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<SEC-DOCUMENT>0000927016-02-003466.txt : 20020628
<SEC-HEADER>0000927016-02-003466.hdr.sgml : 20020628
<ACCEPTANCE-DATETIME>20020628151150
ACCESSION NUMBER:		0000927016-02-003466
CONFORMED SUBMISSION TYPE:	F-3
PUBLIC DOCUMENT COUNT:		6
FILED AS OF DATE:		20020628

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			QIAGEN NV
		CENTRAL INDEX KEY:			0001015820
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				000000000
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		F-3
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-91474
		FILM NUMBER:		02691308

	BUSINESS ADDRESS:	
		STREET 1:		5911 KJ VENLO
		CITY:			SPOORSTRAAT
		STATE:			P7
		ZIP:			50
		BUSINESS PHONE:		31-77-320-8400

	MAIL ADDRESS:	
		STREET 1:		28159 AVENUE STANFORD
		CITY:			VALENCIA
		STATE:			CA
		ZIP:			91355
</SEC-HEADER>
<DOCUMENT>
<TYPE>F-3
<SEQUENCE>1
<FILENAME>df3.txt
<DESCRIPTION>FORM F-3
<TEXT>
<PAGE>

As filed with the Securities and Exchange Commission on June 28, 2002.
                                                      Registration No. 333-_____
- --------------------------------------------------------------------------------
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ----------------------
                                    FORM F-3
                             REGISTRATION STATEMENT
                                      Under
                           THE SECURITIES ACT OF 1933
                                   QIAGEN N.V.
             (Exact name of registrant as specified in its charter)

<TABLE>
<S>                                                   <C>                                  <C>
                 The Netherlands                               2836/3559                                Not Applicable
(State or other jurisdiction of incorporation or      (Primary Standard Industrial         (I.R.S. Employer Identification Number)
                  organization)                       Classification Code Number)
</TABLE>

                                 Spoorstraat 50
                                  5911 KJ Venlo
                                 The Netherlands
                                 +31-77-320-8400
   (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)
                                  Byron Hewett
                   Senior Vice President, Sales and Marketing
                                  QIAGEN, Inc.
                              28159 Avenue Stanford
                               Valencia, CA 91355
                                 (661) 294-7940
 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
                                 With a copy to:
                          Jonathan L. Kravetz, Esquire
               Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                              One Financial Center
                           Boston, Massachusetts 02111
                                 (617) 542-6000

     Approximate date of commencement of proposed sale to the public: As soon as
practical after this Registration Statement becomes effective.

     If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box.                                                                         [_]

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933 other than securities offered only in connection with dividend or interest
reinvestment, check the following box.                                       [X]

     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering.                      [_]

     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering.                                                       [_]

     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box.                                              [_]

<TABLE>
<CAPTION>
                                           CALCULATION OF REGISTRATION FEE
=========================================================================================================================
                                                                                Proposed Maximum
Title of Each Class of          Amount to be        Proposed Maximum            Aggregate Offering        Amount of
Securities to be Registered    Registered/(1)/   Offering Price per Share/(2)/        Price           Registration Fee
- -------------------------------------------------------------------------------------------------------------------------
<S>                            <C>               <C>                            <C>                   <C>
Common shares, EURO 0.01 par      564,334                $10.95                   $6,179,457.30            $568.51
value
=========================================================================================================================
</TABLE>

/(1)/ Includes (i) 564,334 common shares to be offered and sold by the selling
shareholders and (ii) an indeterminate number of additional common shares as may
from time to time become issuable by reason of stock splits, stock dividends and
other similar transactions, which shares are registered hereunder pursuant to
Rule 416.
/(2)/ The price of $10.95 per share which was the average of the high and low
prices of the common shares reported by the Nasdaq Stock Market on June 26,
2002, is set forth solely for the purpose of calculating the registration fee in
accordance with Rule 457(c) of the Securities Act of 1933, as amended.

The Registrant hereby amends this Registration Statement on such date or dates
as may be necessary to delay its effective date until the Registrant shall file
a further amendment which specifically states that this Registration Statement
shall thereafter become effective in accordance with Section 8(a) of the
Securities Act of 1933 or until the Registration Statement shall become
effective on such date as the Commission, acting pursuant to said Section 8(a),
may determine.

<PAGE>

                                   QIAGEN N.V.

                              564,334 Common Shares
                         (par value EUR 0.01 per share)

     We are registering 564,334 common shares for sale by the securityholders
identified in this prospectus as the selling shareholders.

     The selling shareholders may sell the common shares at prices and on terms
determined by the market, in negotiated transactions or through underwriters.
The selling shareholders are identified and information with respect to them is
provided under the caption "Selling Shareholders" in this prospectus.

     We will not receive any of the proceeds from the sale of such shares.


Investing in our common shares involves risks. See "Risk Factors" beginning on
page 5.


     Our common shares are listed on the Nasdaq National Market under the symbol
"QGENF" and on the Neuer Markt trading segment of the Frankfurt Stock Exchange
under the symbol "QIA." On June 26, 2002, the last reported sale price of our
common shares on the Nasdaq National Market was $11.06.

     Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.

                 The date of this prospectus is June __, 2002.

<PAGE>

                   ENFORCEABILITY OF CERTAIN CIVIL LIABILITIES

     We are incorporated under the laws of The Netherlands and a substantial
portion of our assets are located outside the United States. In addition,
members of our Managing and Supervisory Boards, our officers and certain experts
named herein reside outside the United States. As a result, it may be difficult
for investors to effect service of process within the United States upon us or
such other persons, or to enforce outside the United States judgments obtained
against such persons in U.S courts, in any action, including actions predicated
upon the civil liability provisions of U.S. securities laws. In addition, it may
be difficult for investors to enforce, in original actions brought in courts in
jurisdictions located outside the United States, rights predicated upon the U.S.
securities laws.

     We have been advised by legal counsel in The Netherlands, De Brauw
Blackstone Westbroek N.V., that the United States and The Netherlands do not
currently have a treaty providing for reciprocal recognition and enforcement of
judgments (other than arbitration awards) in civil and commercial matters.
Therefore, a final judgment for the payment of money rendered by any federal or
state court in the United States based on civil liability, whether or not
predicated solely upon the federal securities laws, would not be directly
enforceable in The Netherlands. However, if the party in whose favor such final
judgment is rendered brings a new suit in a competent court in The Netherlands,
such party may submit to the Dutch court the final judgment which has been
rendered in the United States. If the Dutch court finds that the jurisdiction of
the federal or state court in the United States has been based on grounds which
are internationally acceptable and that proper legal procedures have been
observed, the Dutch court will, in principle, give binding effect to the final
judgment which has been rendered in the United States unless such judgment
contravenes Dutch principles of public policy. Based on the foregoing, there can
be no assurance that U.S. investors will be able to enforce against us, members
of our Managing or Supervisory Boards, officers or certain experts named herein
who are residents of The Netherlands or countries other than the United States
any judgments obtained in U.S. courts in civil and commercial matters, including
judgments under the federal securities laws. In addition, there is doubt as to
whether a Dutch court would impose civil liability on such persons in an
original action predicated solely upon the federal securities laws of the United
States brought in a competent court in The Netherlands against us or such
members, officers or experts, respectively. See "Risk Factors--Enforcement of
Judgments".


                 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

     The SEC allows us to "incorporate by reference" the information we file
with it, which means that we can disclose important information to you by
referring you to those documents. The information incorporated by reference is
considered to be a part of this prospectus, and information that we file later
with the SEC will automatically update and supersede this information. We
incorporate by reference the documents listed below and any future filings made
with the SEC under Sections 13(a), 13(c) or 15(d) of the Securities Exchange Act
of 1934 until all of the common shares are sold. The documents we are
incorporating by reference are:

          1. Our Annual Report on Form 20-F for the fiscal year ended December
     31, 2001, filed on April 2, 2002;

          2. Our reports on Form 6-K, including our report for the quarterly
     period ended March 31, 2002, filed on May 31, 2002; and our report dated
     June 19, 2002, which includes a copy of our proxy statement dated May 15,
     2002 and our 2001 annual report, filed on June 20, 2002;

          3. All other documents or reports filed by the Company pursuant to
     Section 13(a), 13(c) or 15(d) of the United States Securities Exchange Act
     of 1934, as amended (the "Exchange Act"), after the date of this Prospectus
     and prior to the termination of the offering of the common shares offered
     hereby, including all annual reports on Form 20-F and any Form 6-K which we
     file with the Commission wherein we identify that such form is being
     incorporated by reference into this prospectus; and

          4. The description of our common shares contained in our registration
     statement on Form 8-A filed with the Commission on June 14, 1996, including
     any amendments or reports filed for purposes of updating such description.

                                       2

<PAGE>

     On May 28, 2002, we announced that we had entered into an agreement to
acquire GenoVision AS, a Norwegian company focused on the development of
reagents and solutions for certain nucleic acid diagnostic markets, such as the
HLA market. We completed this acquisition on June 14, 2002. Subject to the terms
of the agreement, we paid approximately $14 million in cash and issued
approximately 940,000 shares of our common stock in exchange for all of the
outstanding stock of GenoVision. In addition, we agreed to pay a success fee of
up to $3 million based on GenoVision's performance in the twelve months
following the acquisition.

     We will provide without charge to each person, including any beneficial
owner, to whom a copy of this prospectus is delivered, upon the written or oral
request of any such person, a copy of any or all of the documents which are
incorporated herein by reference, other than exhibits to such documents (unless
such exhibits are specifically incorporated by reference in such documents).
Requests should be directed to the Company, Spoorstraat 50, 5911 KJ Venlo, The
Netherlands, Attention: Secretary, telephone: +31-77-320-8400.

     Any statement contained in a document all or a portion of which is
incorporated or deemed to be incorporated by reference herein shall be deemed to
be modified or superseded for purposes of this prospectus to the extent that a
statement contained herein or in any other subsequently filed document which
also is or is deemed to be incorporated by reference herein modifies or
supersedes such statement. Any statement so modified, shall not be deemed to
constitute a part of this prospectus except as so modified, and any statement so
superseded shall not be deemed to constitute a part of this prospectus.


                              AVAILABLE INFORMATION

     We have filed with the Commission in Washington, D.C. a Registration
Statement on Form F-3 (the "Registration Statement") under the United States
Securities Act of 1933, as amended (the "Securities Act"), with respect to the
common shares offered hereby. This prospectus, which constitutes part of the
Registration Statement, does not contain all of the information set forth in the
Registration Statement and the exhibits and schedules filed therewith, certain
portions of which have been omitted as permitted by the rules and regulations of
the Commission. For further information with respect to us and the common shares
offered hereby, reference is made to such Registration Statement and to the
exhibits and schedules filed therewith.

     We are subject to the periodic reporting and other informational
requirements of the Exchange Act, applicable to foreign private issuers, and in
accordance therewith we file or furnish reports and other information with or to
the Commission. The Registration Statement (with exhibits), as well as such
reports and other information filed or furnished by us, may be inspected and
copied at prescribed rates at the public reference facilities maintained by the
Commission at its principal offices at Room 1024, 450 Fifth Street, N.W.,
Washington, D.C. 20549, and at the Commission's Regional Offices located at
Northwest Atrium Center, 500 West Madison Street, Suite 1400, Chicago, Illinois
60661, and 7 World Trade Center, New York, New York 10048. Copies of such
material may also be obtained by mail from the Public Reference Section of the
Commission, 450 Fifth Street, N.W., Washington, D.C. 20549 at prescribed rates.

                                       3

<PAGE>

                               PROSPECTUS SUMMARY

     This summary highlights information incorporated by reference or contained
elsewhere in this prospectus. It is not complete and may not contain all of the
information that you should consider before investing in our securities. You
should read the entire prospectus and the documents incorporated by reference
herein carefully, including the "Risk Factors" section contained herein and the
more detailed financial statements, and notes to financial statements,
incorporated by reference in this prospectus.


                                   The Company

     We were incorporated on April 29, 1996 as a public limited liability
company ("naamloze vennnootschap") under Dutch law as a holding company for our
wholly owned subsidiaries, and have our legal seat in Venlo, The Netherlands. As
a holding company, we conduct our business through our wholly-owned
subsidiaries:

        .  QIAGEN GmbH (Germany),
        .  QIAGEN Ltd. (England),
        .  QIAGEN AG (Switzerland),
        .  QIAGEN S.A. (France),
        .  QIAGEN Pty. Ltd. (Australia),
        .  QIAGEN Inc. (Canada),
        .  QIAGEN K.K. (Japan)
        .  QIAGEN S.p.A. (Italy),
        .  QIAGEN Instruments AG, formerly Rosys Instruments AG (Switzerland),
        .  QIAGEN Operon GmbH (Germany),
        .  Sawady Technologies Co., Ltd. (Japan), and
        .  QIAGEN North American Holdings, Inc. (United States).

     QIAGEN North American Holdings, Inc. wholly owns our other U.S.
subsidiaries: QIAGEN, Inc., QIAGEN Sciences, Inc. QIAGEN Genomics, Inc. and
QIAGEN Operon, Inc. (United States). In addition, we own 50% of PreAnalytiX GmbH
(Germany) and 55% of Accord Co., Ltd. (Japan).

     We believe, based on the nature of our products and technologies and on our
United States and European market shares as supported by independent market
studies, that we are the world's leading provider of innovative enabling
technologies and products for the separation and purification of nucleic acids.
Since 1986, we have developed and marketed a broad range of proprietary products
for the academic and industrial research market. The increased understanding of
nucleic acid structure and function combined with the development of
technologies such as Polymerase Chain Reaction (PCR) have resulted in a rapid
expansion in the potential uses of nucleic acids beyond the research market into
developing commercial markets. These include (1) genomics, (2) nucleic
acid-based molecular diagnostics, and (3) genetic vaccination and gene therapy.
We believe that by targeting our enabling nucleic acid separation and
purification technologies to numerous participants in each of these developing
commercial markets, we will optimize and diversify our opportunities for growth.

     Our objective is to expand our leadership position by employing the
following strategies: (1) to expand our leadership in the research market and to
leverage such leadership to diversify its opportunities for future growth into
an array of developing commercial markets, (2) to maintain and further expand
technology leadership by investing significant resources in research and
development and through strategic acquisitions, (3) to provide a comprehensive
portfolio of products for specific nucleic acid handling, separation and
purification applications, (4) to accelerate consumable sales through new
automation product lines, and (5) to emphasize customer contacts and service.

     On April 17, 2002, we completed the acquisition of Xeragon, Inc. of
Huntsville, Alabama, pursuant to an agreement and plan of merger with Xeragon
dated as of March 28, 2002. In connection with this acquisition, we issued
564,334 of our common shares to the shareholders of Xeragon in exchange for all
of the outstanding capital stock of Xeragon. We structured this acquisition to
qualify as a tax-free reorganization. Established in 2001,

                                       4

<PAGE>

Xeragon is a market and technology leader for products and services focusing on
synthetic nucleic acids, particularly siRNA. Since synthetic nucleic acids are
used in the analysis of nucleic acids purified from natural sources, we believe
that Xeragon's products will be highly synergistic with our own and will enable
us to extend significantly our presence into the genomics and genetic analysis
markets.

     On May 28, 2002, we announced that we had entered into an agreement to
acquire GenoVision AS, a Norwegian company focused on the development of
reagents and solutions for certain nucleic acid diagnostic markets, such as the
HLA market. We completed this acquisition on June 14, 2002. Subject to the terms
of the agreement, we paid approximately $14 million in cash and issued
approximately 940,000 shares of our common stock in exchange for all of the
outstanding stock of GenoVision. In addition, we agreed to pay a success fee of
up to $3 million based on GenoVision's performance in the twelve months
following the acquisition. We believe that this acquisition will provide us with
unique, automated solutions for the purification of nucleic acids based on
GenoVisions' proprietary magnetic particle technology. Genovision has two wholly
owned subsidiaries: GenoVision VertriebsgesmbH, Austria, and Genovision Inc,
USA. In addition, the company owns a 60% share in Particle Solutions AS, Norway.

     Our principal executive offices are located at Spoorstraat 50, 5911 KJ
Venlo, The Netherlands, telephone number +31-77-320-8400. We are registered with
the trade registry in Venlo, The Netherlands, under no. 12036979. The offices of
QIAGEN GmbH, our principal operating subsidiary, are located at
Max-Volmer-Strasse 4, D-40724 Hilden, Germany, telephone number +49-2103-29-0.
Parties within the United States may also contact QIAGEN, Inc. in Valencia,
California at 800-426-8157 to obtain information.


                                  RISK FACTORS

     In addition to the other information in this prospectus, prospective
purchasers of the common shares offered hereby should consider carefully the
following risk factors in evaluating us and our business. This prospectus and
the documents incorporated herein by reference contain forward-looking
statements within the meaning of the "safe harbor" provisions of the Private
Securities Litigation Reform Act of 1995. These statements can be identified by
the use of forward-looking terminology such as "may," "will," "could," "expect,"
"anticipate," "estimate," "continue" or other similar words. Reference is made
in particular to the description of our plans and objectives for future
operations, assumptions underlying such plans and objectives, and other
forward-looking statements included in the sections entitled "Prospectus
Summary", and in "Management's Discussion and Analysis of Financial Condition
and Results of Operations" and "Business" incorporated by reference in this
prospectus. Such statements are based on management's current expectations and
are subject to a number of factors and uncertainties which could cause actual
results to differ materially from those described in the forward-looking
statements. Factors which could cause such results to differ materially from
those described in the forward-looking statements include those set forth in the
risk factors below. When considering forward-looking statements, you should keep
in mind that the risk factors could cause our actual results to differ
significantly from those contained in any forward-looking statement.

An inability to manage our growth or the expansion of our operations could
adversely affect our business

     Our business has grown rapidly, with total net revenues increasing from
$75.4 million in 1997 to $263.8 million in 2001. We have recently opened our new
research and manufacturing facility in Germantown, Maryland, upgraded our
operating and financial systems and expanded the geographic area of our
operations, resulting in substantial growth in the number of our employees, as
well as increased responsibility for both existing and new management personnel.
The rapid expansion of our business and growth in personnel may place a strain
on our management and operational systems. Our future operating results will
depend on the ability of our management to continue to implement and improve our
research, product development, sales and marketing and customer support
programs, enhance our operational and financial control systems, expand, train
and manage our employee base, and effectively address new issues related to our
growth as they arise. There can be no assurance that we will be able to manage
our recent or any future expansion successfully, and any inability to do so
could have a material adverse effect on our results of operations.

                                       5

<PAGE>

We may have difficulty integrating acquisitions of technologies and businesses

     During the past several years we have consummated a number of acquisitions
of companies, through which we have gained access to technologies and products
that complement our internally developed product lines. In the future, we may
acquire additional technologies, products or businesses to expand our existing
and planned business. We may not be able to achieve the benefits expected from
any potential acquisition in a reasonable time frame, or at all. Acquisitions
would expose us to the risks associated with the:

     .  assimilation of new technologies, operations, sites and personnel;

     .  diversion of resources from our existing business and technologies;

     .  inability to generate revenues to offset associated acquisition costs;

     .  inability to maintain uniform standards, controls, and procedures;

     .  inability to maintain relationships with employees and customers as a
        result of any integration of new management personnel;

     .  issuance of dilutive equity securities;

     .  incurrence or assumption of debt; or

     .  additional expenses associated with future amortization or impairment of
        acquired intangible assets or potential businesses.

Our failure to address these risks successfully could have a material adverse
effect on our business.

Our operating results may vary significantly

     Our operating results may vary significantly from quarter to quarter and
from year to year, depending on factors such as the level and timing of our
customers' research and commercialization efforts, timing of our customers'
funding, the timing of our research and development and sales and marketing
expenses, the introduction of new products by us or our competitors, competitive
conditions, exchange rate fluctuations and general economic conditions. Our
expense levels are based in part on our expectations as to future revenues.
Consequently, revenues or profits may vary significantly from quarter to quarter
or from year to year, and revenues and profits in any interim period will not
necessarily be indicative of results in subsequent periods.

Our common shares may have a volatile public trading price

     The market price of the common shares since our initial public offering in
June 1996 has increased significantly and been highly volatile. In addition to
overall stock market fluctuations, factors which may have a significant impact
on the market price of the common shares include:

     .  announcements of technological innovations or the introduction of new
        products by us or our competitors;

     .  developments in our relationships with collaborative partners;

     .  quarterly variations in our operating results;

     .  changes in government regulations or patent laws;

                                       6

<PAGE>

     .  developments in patent or other proprietary rights;

     .  and general market conditions relating to the pharmaceutical and
        biotechnology industries.

The stock market has from time to time experienced extreme price and trading
volume fluctuations that have particularly affected the market for
technology-based companies and that have not necessarily been related to the
operating performance of such companies. These broad market fluctuations may
adversely affect the market price of our common shares.

Exchange rate fluctuations may adversely affect our business

     Since we currently market our products in over 42 countries throughout the
world, a significant portion of our business is conducted in currencies other
than the U.S. dollar, our reporting currency. As a result, fluctuations in value
relative to the U.S. dollar of the currencies in which we conduct our business
have caused and will continue to cause foreign currency transaction gains and
losses. Foreign currency transaction gains and losses arising from normal
business operations are charged against earnings in the period incurred. Due to
the number of currencies involved, the variability of currency exposures and the
potential volatility of currency exchange rates, we cannot predict the effects
of exchange rate fluctuations upon future operating results. While we engage in
foreign exchange hedging transactions to manage our foreign currency exposure,
there can be no assurance that our hedging strategy will adequately protect our
operating results from the effects of future exchange rate fluctuations.

We heavily rely on air cargo carriers and other overnight logistics services

     The Company's customers within the scientific research markets typically do
not keep a significant inventory of QIAGEN products and consequently require
overnight delivery of purchases. As such, the Company heavily relies on air
cargo carriers such as FedEx and UPS. If overnight services are suspended or
delayed and other delivery carriers cannot provide satisfactory services,
customers may suspend a significant amount of work requiring nucleic acid
purification. If there are no adequate delivery alternatives available, sales
levels could be negatively affected.

Our continued growth is dependent on the development and success of new products

     Our continued growth is dependent on new product introductions that are
well received in the market. We focus our product development efforts on
expanding our existing products and developing innovative new products in
selected areas where we have expertise and have identified substantial unmet
market needs. There can be no assurance that we will be able to introduce new
products or that new product releases will be successfully launched and received
by our customers.

Competitors may render some or all of our products or future products
noncompetitive

     Our primary competition stems from traditional separation and purification
methods that utilize widely available reagents and other chemicals. The success
of our business depends in part on the continued conversion of current users of
such traditional methods to our nucleic acid-based separation and purification
technologies and products. There can be no assurance, however, as to how quickly
such conversion will occur. We also experience, and expect to continue to
experience, increasing competition in various segments of our nucleic acid-based
separation business from companies providing nucleic acid-based separation
products in kit form. Certain of such competitors have substantially greater
financial, research and development, sales and marketing and personnel resources
than we do and may have significantly more experience in developing,
manufacturing, marketing and supporting new products. There can be no assurance
that such companies will not develop products that are directly competitive with
our current or planned products or that they will not be able to penetrate
markets more rapidly than we can. To the extent that our sales depend on future
sales of diagnostic or therapeutic products by our customers, we may also be
adversely affected by the intense competition in the pharmaceutical and
biotechnology industries. If QIAGEN is not able to maintain its technological
advantage over competing products, to expand its market presence, to preserve
customer loyalty and thus to compete effectively against its existing or future
competitors, QIAGEN's financial condition and results of operations could be
materially adversely affected.

                                       7

<PAGE>

Rapid technological change may render some or all of our technologies and
products obsolete

     Extensive research and technological change characterize our business
environment, and new developments are expected to continue at a rapid pace.
There can be no assurance that developments by others will not render our
technologies and products uneconomical or obsolete.

We depend on patents and proprietary rights that may fail to protect our
business

     Our success will depend to a large extent on our ability to develop
proprietary products and technologies and to establish and protect our patent
and trademark rights with respect thereto. We currently own 32 issued patents in
the United States, 27 issued patents in Germany and 166 issued patents in other
major industrialized countries. In addition, we have approximately 235 pending
patent applications and we intend to file applications for additional patents as
our products and technologies are developed. However, the patent positions of
technology-based companies, including QIAGEN, involve complex legal and factual
questions and may be uncertain, and the laws governing the scope of patent
coverage and the periods of enforceability of patent protection are continuing
to evolve. In addition, patent applications in the United States are maintained
in secrecy until patents issue, and publication of discoveries in the scientific
or patent literature tend to lag behind actual discoveries by several months.
Therefore, no assurance can be given that patents will issue from any patent
applications owned by or licensed to us or, if patents do issue, that the claims
allowed will be sufficiently broad to protect our technology. In addition, no
assurance can be given that any issued patents owned by or licensed to us will
not be challenged, invalidated or circumvented, or that the rights granted
thereunder will provide competitive advantages to us.

     The biotechnology industry has been characterized by extensive litigation
regarding patents and other intellectual property rights. We are aware that
patents have been applied for and/or issued to third parties claiming
technologies for the separation and purification of nucleic acids that are
closely related to those used by us. From time to time we receive inquiries
requesting confirmation that we do not infringe patents of third parties. We
endeavor to follow developments in this field, and we do not believe that our
technologies and/or products infringe any proprietary rights of third parties.
However, there can be no assurance that third parties will not challenge our
activities and, if so challenged, that we will prevail. In addition, the patent
and proprietary rights of others could require us to alter our products or
processes, pay licensing fees or cease certain activities, and there can be no
assurance that we will be able to license any technologies that we may require
on acceptable terms. In addition, litigation, including proceedings that may be
declared by the U.S. Patent and Trademark Office or the International Trade
Commission, may be necessary for us to respond to any assertions of
infringement, enforce our patent rights and/or determine the scope and validity
of our proprietary rights or those of third parties. Litigation could involve
substantial cost to us, and there can be no assurance that we would prevail in
any such proceedings.

     Certain of our products incorporate patents and technologies that are
licensed from third parties. These licenses impose various commercialization,
sublicensing and other obligations on us. Our failure to comply with these
requirements could result in the conversion of the applicable license from being
exclusive to non-exclusive in nature or, in some cases, termination of the
license.

     We also rely on trade secrets and proprietary know-how, which we seek to
protect through confidentiality agreements with our employees and consultants.
There also can be no assurance that any confidentiality agreements between us
and our employees, consultants, outside scientific collaborators and sponsored
researchers and other advisors will provide meaningful protection for our trade
secrets or adequate remedies in the event of unauthorized use or disclosure of
such information. There also can be no assurance that our trade secrets will not
otherwise become known or be independently developed by competitors.

     We currently engage in, and from time to time may engage in, collaborations
with academic researchers and institutions. There can be no assurance that under
the terms of such collaborations, third parties will not acquire rights in
certain inventions developed during the course of the performance of such
collaborations.

                                       8

<PAGE>

We rely on collaborative commercial relationships to develop some of our
products

     Our long-term business strategy includes entering into strategic alliances
or marketing and distribution arrangements with corporate partners relating to
the development, commercialization, marketing and distribution of certain of our
existing and potential products. There can be no assurance that we will be able
to negotiate such collaborative arrangements on acceptable terms, or that any
such relationships will be scientifically or commercially successful. In
addition, there can be no assurance that we will be able to maintain such
relationships or that our collaborative partners will not pursue or develop
competing products or technologies, either on their own or in collaboration with
others.

Our ability accurately to forecast our results during each quarter is impacted
by the fact that a substantial percentage of our sales are booked in the final
weeks or days of the quarter.

     The markets we serve are characterized by a high percentage of purchase
orders being received in the final few weeks or even days of each quarter.
Although this varies from quarter to quarter, increasingly our customers
generally make a large portion of their purchase decisions late in each fiscal
quarter, as both their budgets and requirements for the coming quarter become
clearer. As a result, even late in each fiscal quarter, we cannot predict with
any certainty whether our revenue forecasts for the quarter will be achieved.
Historically, we have been able to rely on the overall pattern of customer
purchase orders during prior periods to project with reasonable accuracy our
anticipated sales for the current or coming quarters. However, if our customers'
purchases during a quarter vary from historical patterns, our final quarterly
results could deviate significantly from our projections. Consequently, our
revenue forecasts for any given quarter may prove not to have been accurate.
Because of the end-of-quarter buying patterns of our customers, we may not have
enough information to confirm or revise our sales projections during the
quarter. If we fail to achieve our forecasted revenues for a particular quarter,
our stock price could be adversely affected.

                                       9

<PAGE>

We have risks relating to doing business internationally

     Our business involves operations in several countries. Our current
consumable and BioRobot production and manufacturing facilities are located in
Germany, our instrumentation facility is located in Switzerland, and we have
added, through the acquisition of the Sawady group of companies in Tokyo, and
establishment of QIAGEN Operon GmbH in Cologne, our synthetic DNA production
businesses in Japan and Germany. We expect to begin production of certain of our
consumable products at our new facility in Germantown, Maryland in the second
quarter of 2002. We also operate U.S. facilities in Alameda, California
(synthetic DNA production), Valencia, California (sales and distribution), and
Bothell, Washington (single nucleotide polymorphism (SNP) analyses). We also
have established sales subsidiaries in Japan, the United Kingdom, France,
Switzerland, Australia, Canada and Italy. In addition, our products are sold
through independent distributors serving more than 42 other countries.

     Conducting and launching operations on an international scale requires
close coordination of activities across multiple jurisdictions and time zones
and consumes significant management resources. We have invested heavily in
computerized information systems in order to manage more efficiently the widely
dispersed components of our operations. In the past year, we have expanded our
SAP business information system that integrates our North American and European
subsidiaries.

     Our operations are also subject to other risks inherent in international
business activities, such as general economic conditions in the countries in
which we operate, overlap of different tax structures, unexpected changes in
regulatory requirements, compliance with a variety of foreign laws and
regulations, and longer accounts receivable payment cycles in certain countries.
Other risks associated with international operations include import and export
licensing requirements, trade restrictions, exchange controls and changes in
tariff and freight rates. As a result of the above conditions, an inability to
successfully manage our international operations could have a material adverse
impact on our operations.

Our success depends on the continued employment of our key personnel, any of
whom we may lose at any time

     Our success depends, to a significant extent, on key members of our
management and scientific staff. The loss of such employees could have a
material adverse effect on us. Our ability to recruit and retain qualified
skilled personnel to perform future research and development work will also be
critical to our success. Due to the intense competition for experienced
scientists from numerous pharmaceutical and biotechnology companies and academic
and other research institutions, there can be no assurance that we will be able
to attract and retain such personnel on acceptable terms. Our planned activities
will also require additional personnel, including management, with expertise in
areas such as manufacturing and marketing, and the development of such expertise
by existing management personnel. The inability to recruit such personnel or
develop such expertise could have a material adverse impact on our operations.

Our business may require substantial additional capital, which we may not be
able to obtain on commercially reasonable terms, if at all

     Our future capital requirements and level of expenses will depend upon
numerous factors, including the costs associated with:

     .  our marketing, sales and customer support efforts;

     .  our research and development activities;

     .  the expansion of our facilities;

     .  the consummation of possible future acquisitions of technologies,
        products or businesses;

     .  the demand for our products and services; and

                                       10

<PAGE>

     .  the refinancing of debt.

     In addition, we have outstanding loan facilities at March 31, 2002 of
approximately $70.0 million, of which approximately $61.2 million will become
due in May 2003. To the extent that our existing resources are insufficient to
fund our activities, we may need to raise funds through public or private
financings of debt or equity securities. No assurance can be given that such
additional financings will be available or, if available, can be obtained on
terms acceptable to us. If adequate funds are not available, we may have to
reduce expenditures for research and development, production or marketing, which
could have a material adverse effect on our business. To the extent that
additional capital is raised through the sale of equity, the issuance of such
securities could result in dilution to our shareholders.

Changing government regulations may adversely impact our business

     QIAGEN and our customers operate in a highly regulated environment
characterized by continuous changes in the governing regulatory framework.
Genetic research activities as well as products commonly referred to as
"genetically engineered" - such as certain food and therapeutic products - are
subject to governmental regulation in most developed countries, especially in
the major markets for pharmaceutical and diagnostic products (i.e., the European
Union, the United States, and Japan). In the recent past, several highly
publicized scientific successes (most notably in the areas of genomic research
and "cloning") have stirred a public debate in which ethical, philosophical and
religious arguments have been raised against an unlimited expansion of genetic
research and the use of products developed thereby. As a result of this debate,
some key countries might increase the existing regulatory barriers; this, in
turn, could adversely affect the demand for our products and prevent us from
fulfilling our growth expectations. Furthermore, there can be no assurance that
any future changes of applicable regulations will not require further
expenditures or an alteration, suspension or liquidation of our operations in
certain areas, or even in their entirety.

Additionally, we are subject to various laws and regulations generally
applicable to businesses in the different jurisdictions in which we operate,
including laws and regulations applicable to the handling and disposal of
hazardous substances. We do not expect compliance with such laws to have a
material effect on our capital expenditures, earnings or competitive position.
Although we believe that our procedures for handling and disposing of hazardous
materials comply with the standards prescribed by applicable regulations, the
risk of accidental contamination or injury from these materials cannot be
completely eliminated. In the event of such an accident, we could be held liable
for any damages that result, and any such liability could have a material
adverse effect on us.

     Sales volumes of certain of our products in development may be dependent on
commercial sales by our customers of diagnostic and pharmaceutical products,
which will require pre-clinical studies and clinical trials. Such trials will be
subject to extensive regulation by governmental authorities in the United States
and other countries and could impact customer demand for our products.

Risk of price controls is a threat to our profitability

     The ability of many of our customers to successfully market their products
depends in part on the extent to which reimbursement for the costs of these
products is available from governmental health administrations, private health
insurers and other organizations. Governmental and other third party payers are
increasingly seeking to contain health care costs and to reduce the price of
medical products and services. Therefore, the biotech industry, the diagnostics
industry and the pharmaceutical industry, as a whole, is exposed to the
potential risk of price controls by these entities. If there are not adequate
reimbursement levels, the commercial success of our customers and, hence, of
QIAGEN itself - could be adversely affected.

Our business exposes us to potential product liability

     The marketing and sale of nucleic acid-based products and services for
certain applications entail a potential risk of product liability, and there can
be no assurance that product liability claims will not be brought against us. We
currently carry product liability insurance coverage, which is limited in scope
and amount, but which

                                       11

<PAGE>

we believe is currently appropriate for our purposes. There can be no assurance,
however, that we will be able to maintain such insurance at reasonable cost and
on reasonable terms, or that such insurance will in fact be adequate to protect
us against any or all potential claims or losses.

Provisions of our Articles of Association and Dutch law may inhibit a takeover,
which could limit the price investors might be willing to pay in the future for
our common shares

     Our Articles of Association (the "Articles of Association") and the
applicable laws of The Netherlands contain provisions that may have
anti-takeover effects. Among other things, the Articles of Association provide
that our joint meeting of the Supervisory Board and Managing Board (the "Joint
Meeting") may make binding nominations for the election of directors, which can
only be overridden by shareholders with a two-thirds majority of the votes cast,
which majority must represent more than 50 percent of the outstanding shares;
that preference shares may in certain instances be issued to third parties
selected by us giving such parties preferred dividend rights and placing
additional votes in hands friendly to our Supervisory Board; that significant
transactions such as a merger or sale of substantially all our assets can only
be approved by specified super-majority votes unless such transactions were
proposed to the general meeting by the Supervisory Board; and that the Articles
of Association can only be amended based on a proposal of our Supervisory Board.
Such provisions may have the effect of delaying, deterring or preventing a
change in control that might otherwise be considered to be in the best interest
of shareholders.

Our holding company structure makes us dependent on the operations of our
subsidiaries

     We were incorporated under Dutch law as a public limited liability company
and we are organized as a holding company. Currently, our material assets are
the outstanding shares of our subsidiaries. We, therefore, are dependent upon
payments, dividends and distributions from our subsidiaries for funds to pay our
operating and other expenses and to pay future cash dividends or distributions,
if any, to holders of the common shares. The lending arrangement entered into by
QIAGEN GmbH with a group of banks led by Deutsche Bank in 2001, limits the
amount of distributions that can be made to QIAGEN N.V. during the period the
borrowings are outstanding. Dividends or distributions by subsidiaries to us in
a currency other than the U.S. dollar may result in a loss upon a subsequent
conversion or disposition of such foreign currency, including a subsequent
conversion into U.S. dollars.

We do not anticipate paying dividends on our common shares

     We have not paid cash dividends since our inception and do not anticipate
paying any cash dividends on the common shares for the foreseeable future.
Although we do not anticipate paying any cash dividends, any cash dividends paid
in a currency other than the U.S. dollar will be subject to the risk of foreign
currency transaction losses.

Future sales of our common shares could adversely affect our stock price

     Future sales of substantial amounts of our common shares in the public
market, or the perception that such sales may occur, could adversely affect the
market price of the common shares. As of June 14, 2002, we had outstanding
144,384,622 common shares plus 8,668,700 outstanding stock options, of which
4,678,011 were exercisable at June 14, 2002. A total of 18,968,000 common shares
are reserved for issuance under our stock option plan. All of our outstanding
common shares are freely saleable except 12,250,612 shares held by our
affiliates, which are subject to certain limitations on resale.

United States civil liabilities may not be enforceable against us

     We are incorporated under the laws of The Netherlands and substantial
portions of our assets are located outside the United States. In addition,
certain members of our Managing and Supervisory Boards, our officers and certain
experts named herein reside outside the United States. As a result, it may be
difficult for investors to effect service of process within the United States
upon us or such other persons, or to enforce outside the U.S. judgments obtained
against such persons in U.S. courts, in any action, including actions predicated
upon the civil liability provisions of

                                       12

<PAGE>

U.S. securities laws. In addition, it may be difficult for investors to enforce,
in original actions brought in courts in jurisdictions located outside the
United States, rights predicated upon the U.S. securities laws. There is no
treaty between the United States and The Netherlands for the mutual recognition
and enforcement of judgments (other than arbitration awards) in civil and
commercial matters. Therefore, a final judgment for the payment of money
rendered by any federal or state court in the United States based on civil
liability, whether or not predicated solely upon the federal securities laws,
would not be directly enforceable in The Netherlands. However, if the party in
whose favor such final judgment is rendered brings a new suit in a competent
court in The Netherlands, such party may submit to the Dutch court the final
judgment which has been rendered in the United States. If the Dutch court finds
that the jurisdiction of the federal or state court in the United States has
been based on grounds which are internationally acceptable and that proper legal
procedures have been observed, the Dutch court will, in principle, give binding
effect to the final judgment which has been rendered in the United States unless
such judgment contravenes Dutch principles of public policy. Based on the
foregoing, there can be no assurance that U.S. investors will be able to enforce
against us, members of our Managing or Supervisory Boards, officers or certain
experts named herein who are residents of The Netherlands or countries other
than the United States any judgments obtained in U.S. courts in civil and
commercial matters, including judgments under the federal securities laws. In
addition, there is doubt as to whether a Dutch court would impose civil
liability on us, the members of our Managing or Supervisory Boards, our officers
or certain experts named herein in an original action predicated solely upon the
federal securities laws of the United States brought in a court of competent
jurisdiction in The Netherlands against us or such members, officers or experts,
respectively.

Risks and Uncertainties Regarding Forward-Looking Statements

     This Prospectus contains certain forward-looking statements that are
subject to certain risks and uncertainties. These statements include statements
regarding (i) our ability to maintain relationships with our customers and our
broad range of products, (ii) our ability to stay abreast of technological
developments, (iii) the size of our markets and potential markets, (iv) our
ability to penetrate and expand these markets and the demand for our products,
(v) our ability to increase our production efficiency as a result of expansion
in our production capacity, and (vi) our liquidity. Such statements are based on
management's current expectations and are subject to a number of factors and
uncertainties that could cause actual results to differ materially from those
described in the forward-looking statements. We caution investors that there can
be no assurance that actual results or business conditions will not differ
materially from those projected or suggested in such forward-looking statements
as a result of various factors, including, but not limited to, the following:
risks associated with our expansion of operations, management growth,
international operations, and dependence on key personnel; intense competition;
the variation in our operating results; technological change; our ability to
develop and protect proprietary products and technologies and to enter into
collaborative commercial relationships; our ability to integrate acquisitions of
technologies and businesses; our future capital requirements; and uncertainties
as to the extent of future government regulation of our business. As a result,
our future development efforts involve a high degree of risk.


                                 DIVIDEND POLICY

     We have never paid cash dividends on our share capital. We currently intend
to retain any earnings to finance the growth and development of our business
and, therefore, do not intend to pay dividends on our share capital for the
foreseeable future.


                                 USE OF PROCEEDS

     All net proceeds from the sale of the common shares being offered will go
to the the selling shareholders who offer and sell their shares. Accordingly, we
will not receive any proceeeds from the selling shareholders' sale of their
common shares.

                                       13

<PAGE>

                              SELLING SHAREHOLDERS

     The following table sets forth certain information regarding the beneficial
ownership of the Company's common shares as of June 26, 2002 by each selling
shareholder both before and after giving effect to this offering. Each of the
selling shareholders received his or her common shares in connection with our
acquisition of Xeragon, Inc.

<TABLE>
<CAPTION>
                                                                           Number of
                                                                           ---------
                                               Number of Common             Common            Number of Common
                                               ----------------             ------            ----------------
                  Name                           Shares Owned               Shares              Shares Owned
                  ----                           ------------               ------              ------------
                                              Prior to Offering            Offered             After Offering
                                              -----------------            -------             --------------

                                               Number(1)      Percent                         Number(1)      Percent
                                               ---------      -------                         ---------      -------
<S>                                           <C>             <C>          <C>                <C>            <C>
Patrick Weiss/(2)/                              143,905          *         143,905                  0           *
Violette Weiss                                  143,905          *         143,905                  0           *
Stefan Pitsch                                   141,084          *         141,084                  0           *
Edgar Rutishauser                                28,217          *          28,217                  0           *
Rolf Stalder                                     28,717          *          28,717                  0           *
James R. Hudson, Jr. and Suanne Hudson           28,717          *          28,717                  0           *
Luzy Jenny                                       23,573          *          23,573                  0           *
James R. Hudson, III                             14,108          *          14,108                  0           *
Cindy Jackson                                    14,108          *          14,108                  0           *
</TABLE>

 *   Less than 1%
(1)  The number of common shares beneficially owned by each shareholder is
     determined under rules promulgated by the Commission, and the information
     is not necessarily indicative of beneficial ownership for any other
     purpose. Under such rules, beneficial ownership includes any common shares
     as to which the individual has sole or shared voting power or investment
     power and also any common shares which the individual has the right to
     acquire within 60 days after June 26, 2002 through the exercise of any
     stock option or other right. The inclusion herein of such common shares,
     however, does not constitute an admission that the named shareholder is a
     direct or indirect beneficial owner of such common shares.

(2)  Patrick Weiss is the President of Xeragon, Inc.


                              Plan of Distribution

     In addition to covering the resale of the above-mentioned common shares,
this prospectus covers an indeterminate number of additional common shares as
may from time to time become issuable as a result of any stock split, stock
dividend, recapitalization, combination, merger, consolidation, distribution or
other similar transactions with respect to the 564,334 common shares discussed
above.

     Our common shares offered in this prospectus were originally issued to the
selling shareholders pursuant to exemptions from the registration requirements
of the Securities Act under Sections 4(2) thereof in connection with our
acquisition of Xeragon, Inc. In accordance with registration rights granted to
the selling shareholders in the Xeragon acquisition, we have filed a
Registration Statement on Form F-3 with the SEC in order to register the
securities for resale. The Registration Statement covers the resale of the
564,334 common shares from time to time on the Nasdaq National Market or in
privately negotiated transactions. This prospectus forms a part of the
Registration Statement. We have also agreed to prepare and file such amendments
and supplements to the Registration Statement as may be necessary to keep the
Registration Statement effective until the earlier of the date when the
securities covered by the Registration Statement may be sold under SEC Rule 144
within a three-month period or such time as all of the securities covered by the
Registration Statement have been sold by the selling shareholders. We

                                       14

<PAGE>

have agreed to pay all reasonable fees and expenses for the registration of the
common shares. We have agreed to indemnify the selling shareholders against
certain losses, claims, damages and liabilities, including liabilities under the
Securities Act, that could arise in connection with the selling shareholders'
sales of their securities.

     Our 564,334 common shares offered in this prospectus may be offered and
sold from time to time by the selling shareholders, or by pledgees, donees,
transferees or other successors in interest selling shares received after the
date of this prospectus from a named selling shareholder as a gift, pledge,
partnership distribution or other non-sale related transfer. Such offers and
sales may be made from time to time on a stock exchange, market or trading
facility on which the securities are traded or in privately negotiated
transactions. These sales may be at prices and on terms prevailing in the
market, at prices related to the market price of our common shares or at
negotiated prices. The selling shareholders may use any one or more of the
following methods when selling the securities:

     .  ordinary brokerage transactions and transactions in which the
        broker-dealer solicits purchasers;

     .  block trades in which the broker-dealer will attempt to sell the shares
        as agent but may position and resell a portion of the block as principal
        to facilitate the transaction;

     .  purchases by a broker-dealer as principal and resale by the broker-
        dealer for its account,

     .  an exchange distribution in accordance with the rules of the relevant
        exchange;

     .  privately negotiated transactions;

     .  short sales;

     .  broker-dealers may agree with the selling shareholders to sell a
        specified number of such shares at a stipulated price per share;

     .  a combination of any such methods of sale; and

     .  any other method permitted by law.

The selling shareholders may also sell shares under Rule 144 under the
Securities Act, if available, rather than under this prospectus.

     From time to time the selling shareholders may engage in short sales, short
sales against the box, puts and calls and other transactions in our securities,
and may sell and deliver the securities in connection with those transactions.
The selling shareholders may pledge their shares to their brokers under the
margin provisions of their customer agreements. If a selling stockholder
defaults on a margin loan, the broker may offer and sell the pledged securities
from time to time.

     Broker-dealers engaged by the selling shareholders may arrange for other
brokers-dealers to participate in sales. Broker-dealers may receive commissions
or discounts from the selling shareholders (or, if any broker-dealer acts as
agent for the purchaser of shares, from the purchaser) in amounts to be
negotiated. The selling shareholders do not expect these commissions and
discounts to exceed what is customary in the types of transactions involved.

     The selling shareholders and any broker-dealers or agents that are involved
in selling the securities may be considered to be "underwriters" within the
meaning of the Securities Act in connection with such sales. If so, any
commissions received by such broker-dealers or agents and any profit on the
resale of the securities purchased by them may be considered to be underwriting
commissions or discounts under the Securities Act.

     In order to comply with the securities laws of some states, the securities
must be offered or sold only through registered or licensed brokers or dealers.
In addition, in some states, the securities may not be offered or sold unless

                                       15

<PAGE>

they have been registered or qualified for sale in that particular state or
unless an exemption from the registration or qualification requirement is
available and is complied with.

     The common shares may be offered anywhere in the world, except that such
offer may only be announced to persons who are established, domiciled or have
their residence outside the Netherlands, provided that (i) the offer and each
announcement of the offer states that the offer is not and will not be made to
persons who are resident in the Netherlands, and (ii) the offer and each
announcement thereof comply with the laws and regulations of any State where
persons to whom the offer is made are resident.

     The anti-manipulative provisions of Regulation M under the Securities
Exchange Act of 1934 may apply to sales of the common shares by the selling
shareholders.

     All proceeds from sales of the 564,334 common shares offered in the
prospectus will be the property of the selling shareholders, each of whom will
bear the expense of underwriting discounts and selling commissions, if any, and
their own related legal fees.


                                  LEGAL MATTERS

     Certain legal matters in connection with this offering will be passed upon
for us by Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston,
Massachusetts, our U.S. counsel. Attorneys at Mintz Levin own an aggregate of
14,000 common shares. The validity of the common shares offered hereby will be
passed upon for us by De Brauw Blackstone Westbroek N.V., Amsterdam, The
Netherlands. Matters of Dutch tax law will be passed upon for us by Baker &
McKenzie, Amsterdam, The Netherlands.


                                     EXPERTS

     The audited financial statements and schedule incorporated by reference in
this prospectus and elsewhere in the registration statement to the extent and
for the periods indicated in their reports have been audited by Arthur Andersen
LLP, independent public accountants, and are included herein in reliance upon
the authority of said firm as experts in accounting and auditing in giving said
reports.

                                       16

<PAGE>

     You should rely only on the information contained in this prospectus. We
have not authorized anyone to provide you with information different from that
contained in this prospectus. The selling shareholders are offering to sell and
seeking offers to buy our common shares only in jurisdictions where offers and
sales are permitted. The information contained in this prospectus is accurate
only as of June __, 2002. You should not assume that this prospectus is accurate
as of any other date.


                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                  Page
                                                  ----
<S>                                                 <C>
Enforceability of Certain Civil Liabilities......   2
Incorporation of Certain Documents by
   Reference.....................................   2
Available Information............................   3
Prospectus Summary...............................   4
Risk Factors.....................................   5
Dividend Policy..................................  13
Use of Proceeds..................................  13
Selling Shareholders.............................  14
Plan of Distribution.............................  14
Legal Matters....................................  16
Experts..........................................  16
</TABLE>


                              564,334 Common Shares
                         (par value EUR 0.01 per share)

                                   QIAGEN N.V.

                                   PROSPECTUS

                                  June __, 2002

<PAGE>

                 PART II. INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution.

     The table sets forth our estimates (other than the SEC and Nasdaq filing
fees) of our expenses in connection with the issuance and distribution of the
common shares being registered. None of the following expenses are being paid by
the selling shareholders.

Item                                                             Amount
                                                                 ------

SEC registration fee.........................................   $568.51
Nasdaq listing fee...........................................
Legal fees and expenses......................................
Accounting fees and expenses.................................   $     0
Miscellaneous fees and expenses..............................   $12,000

Total........................................................   $
                                                                =======


Item 15. Indemnification of Directors and Officers

     The Registrant's Articles of Association provide for indemnification of the
Registrant's directors and officers for liabilities and expenses that they may
incur in such capacities. In general, directors and officers are indemnified
with respect to actions taken in good faith in a manner reasonably believed to
be in, or not opposed to, the best interests of the Registrant, and with respect
to any criminal action or proceeding, actions that the indemnitee had no
reasonable cause to believe were unlawful.

     The Registrant maintains insurance which insures the officers and directors
of the Registrant against certain losses and which insures the Registrant
against certain of its obligations to indemnify such officers and directors.

Item 16. Exhibits and Financial Statement Schedules

     (a) Exhibits

 Exhibit
 -------
 Number                            Description of Exhibits
 ------      ----------------------------------------------------------------

2.1      --Agreement and Plan of Merger by and among QIAGEN N.V., Xenopus Merger
         Sub, Inc. and Xeragon, Inc. dated as of March 28, 2002

4.1      --Articles of Association of Registrant as conformed by notorial deed
         as of July 6, 2000 (English translation) (incorporated by reference to
         Exhibit 1.1 to the Registrant's Annual Report on Form 20-F for the year
         ending December 31, 2001 filed with the Securities Exchange Commission
         on April 2, 2002)

4.2      --Form of Certificate representing Common Shares (incorporated by
         reference to Exhibit 4.1 to the Registrant's Registration Statement on
         Form F-1, No, 333-4922, effective June 27, 1996)

                                      II-1

<PAGE>

5.1      --Opinion of De Brauw Blackstone Westbroek N.V. regarding the legality
         of the common shares being registered

8.1      --Opinion of Baker & McKenzie as to certain Dutch tax matters relative
         to the common shares

8.2      --Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo P.C. as to
         certain U.S. tax matters relative to the common shares

23.1     --Consent of De Brauw Blackstone Westbroek N.V. (included in Exhibit
         5.1)

23.2     --Consent of Baker & McKenzie (included in Exhibit 8.1)

23.3     --Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo P.C.
         (included in Exhibit 8.2)

24.1     --Powers of Attorney (included in Part II)

99.1     --Press release dated April 18, 2002 titled "QIAGEN Aquires Xeragon,
         Inc."

After reasonable effort, the registrant has not been able to obtain the consent
of Arthur Andersen LLP to the incorporation by reference of their report in this
registration statement, and the registrant has dispensed with the requirement to
file their consent in reliance upon Rule 437a promulgated under the Securities
Act. Because Arthur Andersen LLP has not consented to the incorporation by
reference of their report in this registration statement, you will not be able
to recover against Arthur Andersen LLP under Section 11 of the Securities Act
for any untrue statements of a material fact contained in the financial
statements audited by Arthur Andersen LLP incorporated by reference herein or
any ommissions to state a material fact required to be stated therein.

Item 17. Undertakings

A. Rule 415 Offering.

The undersigned registrant hereby undertakes:

     (1) To file, during any period in which offers or sales are being made, a
    post-effective amendment to this registration statement:

         (i)  To include any prospectus required by Section 10(a)(3) of the
         Securities Act of 1933;

         (ii) To reflect in the prospectus any facts or events arising after the
         effective date of the registration statement (or the most recent post-
         effective amendment thereof) which, individually or in the aggregate,
         represent a fundamental change in the information set forth in the
         registration statement. Notwithstanding the foregoing, any increase or
         decrease in volume of securities offered (if the total dollar value of
         securities offered would not exceed that which was registered) and any
         deviation from the low or high end of the estimated maximum offering
         range may be reflected in the form of prospectus filed with the
         Commission pursuant to Rule 424(b)(S).230.424(b) of this chapter) if,
         in the aggregate, the changes in volume and price represent no more
         than a 20% change in the maximum aggregate offering price set forth in
         the "Calculation of Registration Fee" table in the effective
         registration statement; and

         (iii) To include any material information with respect to the plan of
         distribution not previously disclosed in the registration statement or
         any material change to such information in the registration statement;

                                      II-2

<PAGE>

Provided, however, that paragraphs (A)(1)(i) and (A)(1)(ii) do not apply if the
registration statement is on Form S-3, Form S-8 or Form F-3, and the information
required to be included in a post-effective amendment by those paragraphs is
contained in periodic reports filed by the Registrant pursuant to Section 13 or
Section 15(d) of the 1934 Act that are incorporated by reference in the
registration statement.

    (2) That, for the purpose of determining any liability under the Securities
    Act, each such post-effective amendment shall be deemed to be a new
    registration statement relating to the securities offered therein, and the
    offering of such securities at that time shall be deemed to be the initial
    bona fide offering thereof.

    (3) To remove from registration by means of a post-effective amendment any
    of the securities being registered which remain unsold at the termination of
    the offering.

    (4) If the registrant is a foreign private issuer, to file a post-effective
    amendment to the registration statement to include any financial statements
    required by Section 210.3-19 of this chapter at the start of any delayed
    offering or throughout a continuous offering. Financial statements and
    information otherwise required by Section 10(a)(3) of the Act need not be
    furnished, provided that the registrant includes in the prospectus, by means
    of a post-effective amendment, financial statements required pursuant to
    this paragraph (a)(4) and other information necessary to ensure that all
    other information in the prospectus is at least as current as the date of
    those financial statements. Not withstanding the foregoing, with respect to
    registration statements on Form F-3 (Section 239.33 of this chapter), a
    post-effective amendment need not be filed to include financial statements
    and information required by Section 10(a)(3) of the Act or Section 210.3-19
    of this chapter if such financial statements and information are contained
    in periodic reports filed with or furnished to the Commission by the
    registrant pursuant to section 13 or section 15(d) of the Securities
    Exchange Act of 1934 that are incorporated by reference in the Form F-3.

B. Filings Incorporating Subsequent Exchange Act Documents by Reference.

The undersigned registrant hereby undertakes that, for purposes of determining
any liability under the Securities Act of 1933, each filing of the registrant's
annual report pursuant to section 13(a) or section 15(d) of the Securities
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to section 15(d) of the Securities Exchange Act of
1934) that is incorporated by reference in the registration statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.

C. Request for Acceleration of Effective Date.

Insofar as indemnification for liabilities arising under the Securities Act of
1933 may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
of 1933 and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.

                                      II-3

<PAGE>

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form F-3 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Venlo, The Netherlands, on June 28, 2002.

                                             QIAGEN N.V.


                                                       /s/ Peer M. Schatz
                                             -----------------------------------
                                              Peer M. Schatz, Managing Director,
                                                      Chief Financial and
                                                       Accounting Officer


                                POWER OF ATTORNEY

     Each person whose signature appears below constitutes and appoints Metin
Colpan and Peer M. Schatz, and each of them (with full power to act alone) his
true and lawful attorney-in-fact and agent, with full power of substitution and
resubstitution, for him and in his name, place and stead, and in any and all
capacities, to sign any and all amendments (including post-effective amendments)
to this Registration Statement on Form F-3 (and any other registration statement
for the same offering that is to be effective upon filing pursuant to Rule
462(b) under the Securities Act of 1933) of QIAGEN N.V., and to file the same,
with all exhibits thereto and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorney-in-fact and
agent, full power and authority to do and perform each and every act and thing
requisite or necessary to be done in and about the premises, as full to all
intents and purposes as he might or could do in person, hereby ratifying and
conforming all that said attorney-in-fact and agent or his substitute and
substitutes may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities indicated on June ___, 2002.

<TABLE>
<CAPTION>
Signatures                          Title                                           Date
- ----------                          -----                                           ----
<S>                                 <C>                                             <C>
/s/ Dr. Metin Colpan                Managing Director, Chief Executive Officer      June 28, 2002
- ------------------------------
Dr. Metin Colpan

/s/ Peer M. Schatz                  Managing Director, Chief Financial Officer      June 28, 2002
- ------------------------------
Peer M. Schatz

/s/ Prof. Dr. Detlev Riesner        Chairman of the Board, Supervisory Director     June 28, 2002
- ------------------------------
Prof. Dr. Detlev Riesner

/s/ Franz A. Wirtz                  Supervisory Director                            June 28, 2002
- ------------------------------
Dr. Franz A. Wirtz

/s/ Jochen Walter
- ------------------------------      Supervisory Director                            June 28, 2002
Jochen Walter

/s/ Erik Hornnaess                  Supervisory Director                            June 28, 2002
- ------------------------------
Erik Hornnaess

/s/ Dr. Manfred Karobath            Supervisory Director                            June 28, 2002
- ------------------------------
Dr. Manfred Karobath

/s/ Dr. Heinrich Hornef             Supervisory Director                            June 28, 2002
- ------------------------------
Dr. Heinrich Hornef
</TABLE>

                                      II-4

<PAGE>

              SIGNATURE OF AUTHORIZED REPRESENTATIVE OF QIAGEN N.V.

     Pursuant to the Securities Act of 1933, as amended, the undersigned, the
duly authorized representative in the United States of QIAGEN N.V., has signed
this Registration Statement in Valencia, California on June 28, 2002.

                                              By:  /s/ Byron Hewett
                                                   ---------------------------

                                                   Byron Hewett

                                      II-5

<PAGE>

                                  EXHIBIT INDEX

Exhibit
- -------
Number                        Description of Exhibits
- ------   -----------------------------------------------------------------------

2.1      Agreement and Plan of Merger by and among QIAGEN N.V., Xenopus Merger
         Sub, Inc. and Xeragon, Inc. dated as of March 28, 2002.

4.1      Articles of Association of Registrant as conformed by notorial deed as
         of July 6, 2000 (English translation) (incorporated by reference to
         Exhibit 1.1 to the Registrant's Annual Report on Form 20-F for the year
         ending December 31, 2001 filed with the Securities Exchange Commission
         on April 2, 2002).

4.2      Form of Certificate representing Common Shares (incorporated by
         reference to Exhibit 4.1 to the Registrant's Registration Statement on
         Form F-1, No, 333-4922, effective June 27, 1996).

5.1      Opinion of De Brauw Blackstone Westbroek N.V. regarding the legality of
         the common shares being registered.

8.1      Opinion of Baker & McKenzie as to certain Dutch tax matters relative to
         the common shares.

8.2      Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo P.C. as to
         certain U.S. tax matters relative to the common shares.

23.1     Consent of De Brauw Blackstone Westbroek N.V. (included in Exhibit
         5.1).

23.2     Consent of Baker & McKenzie (included in Exhibit 8.1).

23.3     Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo P.C. (included
         in Exhibit 8.2).

24.1     Powers of Attorney (included in Part II).

99.1     Press release dated April 18, 2002 titled "QIAGEN Aquires Xeragon,
         Inc."

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-2.1
<SEQUENCE>3
<FILENAME>dex21.txt
<DESCRIPTION>AGREEMENT AND PLAN OF MERGER
<TEXT>
<PAGE>

                                                                     Exhibit 2.1

                                                                  EXECUTION COPY

                          AGREEMENT AND PLAN OF MERGER

                  AGREEMENT AND PLAN OF MERGER (this "Agreement"), dated as of
March 28, 2002 by and among QIAGEN N.V., a Netherlands corporation ("QIAGEN"),
XENOPUS MERGER SUB, INC., a Delaware corporation and a wholly-owned subsidiary
of QIAGEN ("Merger Sub"), XERAGON, INC., an Alabama corporation (the "Company"),
and the shareholders of the Company listed on Schedule I attached hereto (the
"Company Shareholders").

                  WHEREAS, the Boards of Directors of QIAGEN, Merger Sub and the
Company have each determined that it is in the best interests of their
respective stockholders for QIAGEN to acquire the Company upon the terms and
subject to the conditions set forth herein;

                  WHEREAS, in furtherance of such acquisition, the Boards of
Directors of QIAGEN, Merger Sub and the Company have each approved the merger
(the "Merger") of Merger Sub with and into the Company, and the Company
Shareholders have consented to the Merger, each in accordance with the General
Corporation Law of the State of Delaware (the "DGCL"), and the Alabama Business
Corporation Act (the "ABCA"), as the case may be, subject to the conditions set
forth herein, which Merger will result in, among other things, the Company
becoming a wholly owned subsidiary of QIAGEN, and all of the issued and
outstanding shares of the common stock of the Company, $0.0001 par value per
share (the "Company Shares"), of the Company, held by the Company Shareholders
will be exchanged and converted into shares of Common Stock, Eur. 0.01 par
value, of QIAGEN (the "QIAGEN Common Stock") on the terms described herein;

                  WHEREAS, the shares of QIAGEN Common Stock issuable hereunder
are not and will not be offered to persons who are established, domiciled or
have their residence in the Netherlands. The offer of the shares of QIAGEN
Common Stock issued hereunder, each announcement thereof and this Agreement
comply with the law and regulations of any State where persons to whom the offer
is made are resident.

                  WHEREAS, the Company Shareholders have voted by written
consent in favor of the Merger and to approve this Agreement;

                  WHEREAS, for federal income tax purposes, it is intended that
the Merger shall qualify as a tax-free reorganization with the meaning of
Section 368(a) of the Code and the United States Treasury Regulations
promulgated thereunder; and

                  WHEREAS, the Company and Xeragon AG, a Swiss corporation
("XAG") are parties to that certain License Agreement, dated as of August 1,
2001, (the "Old XAG License Agreement"), pursuant to which XAG has granted to
the Company an exclusive (subject to one limited license agreement with Glen
Research Corporation) license to XAG's Intellectual Property Rights (as defined
herein), and XAG joins in this Agreement in order to assist in the consummation
of the Merger and in anticipation of its relationship with QIAGEN following the
Merger;

<PAGE>

           NOW, THEREFORE, in consideration of the foregoing and the mutual
representations, warranties, covenants and agreements herein contained, and
intending to be legally bound hereby, the Company, QIAGEN, Merger Sub and the
Company Shareholders hereby agree as follows:

                                   ARTICLE 1
                                   THE MERGER

       1.1 The Merger. At the Effective Time (as defined in Section 1.2) and
subject to and upon the terms and conditions of this Agreement and the
provisions of the DGCL and the ABCA, Merger Sub shall be merged with and into
the Company, the separate corporate existence of Merger Sub shall cease and the
Company shall, as the surviving corporation in the Merger, continue its
existence under the provisions of the ABCA as a wholly-owned subsidiary of
QIAGEN. The Company, as the surviving corporation after the Merger, is
hereinafter sometimes referred to as the "Surviving Corporation."

       1.2 Effective Time. As promptly as practicable after the satisfaction or,
to the extent permitted hereunder, waiver of the conditions set forth in Article
7 of this Agreement, the parties hereto shall cause the Merger to be consummated
by filing the Certificate of Merger and the Agreement of Merger, substantially
in the forms set forth in Exhibits A and B attached hereto (the "Certificates of
Merger"), along with a certified copy of this Agreement, if required, and such
other documents as may be required, with the Secretary of State of the State of
Delaware and the Secretary of State of the State of Alabama, executed in
accordance with the relevant provisions of the DGCL and the ABCA (the date and
time of such filing, or such later date and time as may be specified in the
Certificate of Merger by mutual agreement of QIAGEN, Merger Sub and the Company,
being the "Effective Time").

       1.3 Effect of the Merger. At the Effective Time, the effect of the Merger
shall be as provided in the applicable provisions of the DGCL and the ABCA.
Without limiting the generality of the foregoing, and subject thereto, at the
Effective Time, all the property, rights, privileges, powers and franchises of
the Company and Merger Sub shall vest in the Surviving Corporation, and all
debts, liabilities and duties of the Company and Merger Sub shall become the
debts, liabilities and duties of the Surviving Corporation.

       1.4 Articles of Incorporation and By-Laws of Surviving Corporation.
Unless otherwise determined by QIAGEN prior to the Effective Time, at the
Effective Time, the Articles of Incorporation of the Company, as amended by the
Certificates of Merger, shall be the Articles of Incorporation of the Surviving
Corporation until thereafter amended as provided by the ABCA. The by-laws of the
Merger Sub shall be the by-laws of the Surviving Corporation until thereafter
amended as provided by the ABCA.

       1.5 Directors and Officers. The directors of Merger Sub immediately prior
to the Effective Time shall be the initial directors of the Surviving
Corporation, each to hold office in accordance with the Articles of
Incorporation of the Surviving Corporation. The officers of the Merger Sub
immediately prior to the Effective Time shall be the initial officers of the
Surviving Corporation, in each case until their respective successors are duly
elected or appointed and qualified or until their earlier death, resignation or
removal in accordance with the Surviving

                                       2

<PAGE>

Corporation's Articles of Incorporation and by-laws. Prior to the Effective
Time, the Company shall deliver to QIAGEN resignation letters of each of the
directors of the Company to be effective as of such Effective Time.

       1.6   Maximum Merger Consideration; Conversion of Company Shares; Escrow.
             ------------------------------------------------------------------

             (a)    At the Effective Time, by virtue of the Merger and without
any action on the part of the parties hereto:

                    (i)  Subject to the other provisions of this Article 1, each
       Company Share issued and outstanding immediately prior to the Effective
       Time (other than any Company Shares to be canceled pursuant to Section
       1.7 and any Dissenting Shares (as described in Section 1.16)) shall be
       converted automatically into the right to receive (A) the Exchange Ratio
       Fraction of a fully paid and non-assessable share of QIAGEN Common Stock
       (the "Merger Shares") and (B) at the sole election of QIAGEN, either (x)
       the Performance Ratio Fraction of a fully paid and non-assessable share
       of QIAGEN Common Stock (the "Performance Shares") or (y) the Performance
       Payment Amount (the "Performance Cash"), in the case of Merger Shares and
       Performance Shares, together with cash, if any, in lieu of any fraction
       of a share of QIAGEN Common Stock pursuant to Section 1.09 (collectively,
       the "Merger Consideration").

                    (ii) For purposes of this Agreement:

                         (A) the term "Acquisition Amount" shall mean $8,000,000
                    (which Acquisition Amount represents the aggregate fixed
                    portion of the purchase price for the Company Shares);

                         (B) the term "Company Shares Number" means (A) the sum
                    of all Company Shares outstanding immediately prior to the
                    Effective Time, minus (B) Company Shares to be canceled
                    pursuant to Section 1.7;

                         (C) the term "Closing Date Average" shall mean the
                    average of the closing prices of QIAGEN Common Stock
                    (rounded to the nearest cent) on the Nasdaq National Market
                    (as reported on the Nasdaq web site) on the ten (10)
                    consecutive trading days ending on the trading day
                    immediately prior to the Effective Time; provided, however,
                    that if the Closing Date Average is lower than $14.00, the
                    Closing Date Average shall be deemed to be $14.00 for
                    purposes of this Section 1.6;

                         (D) the term "Exchange Ratio Fraction" shall mean the
                    quotient (calculated to the nearest five (5) decimal places)
                    obtained by (I) dividing (x) the Acquisition Amount by (y)
                    the Closing Date Average, and (II) dividing the quotient
                    computed thereby by the Company Shares Number;

                         (E) the term "Performance Amount" shall mean $600,000
                    multiplied by the sum of the Performance Expense Multiplier
                    and the Performance Revenue Multiplier (which Performance
                    Amount represents

                                       3

<PAGE>

              the aggregate variable portion of the purchase price for the
              Company Shares);

                     (F) the term "Performance Average" shall mean the average
              of the closing prices of QIAGEN Common Stock (rounded to the
              nearest cent) on the Nasdaq National Market (as reported on the
              Nasdaq web site) on the ten (10) consecutive trading days ending
              on December 31, 2003; provided, however, that the Performance
              Average shall in no event be less than $14.00 (adjusted for any
              stock dividend, stock split, combination, or similar
              recapitalization occurring from and after the date of this
              Agreement and before December 31, 2003);

                     (G) the term "Performance Expense Multiplier" shall mean
              (I) zero if the Xeragon Expense Percentage is greater than or
              equal to 42%, (II) one if the Xeragon Expense Percentage is less
              than or equal to 35% and (III) otherwise the result obtained by
              dividing (y) the difference between 42% and the Xeragon Expense
              Percentage by (z) 7%;

                     (H) the term "Performance Ratio Fraction" shall mean the
              quotient (calculated to the nearest five (5) decimal places)
              obtained by (I) dividing (x) the Performance Amount by (y) the
              Performance Average, and (II) dividing the quotient computed
              thereby by the Company Shares Number;

                     (I) the term "Performance Payment Amount" shall mean the
              quotient (calculated to the nearest five (5) decimal places)
              obtained by (I) dividing (x) the Performance Amount by (y) the
              Company Shares Number;

                     (J) the term "Performance Revenue Multiplier" shall mean
              (I) zero if the Xeragon Revenues are less than or equal to
              $8,800,000, (II) one if the Xeragon Revenues are equal to or
              greater than $11,000,000 and (III) otherwise the result obtained
              by dividing (y) the difference between the Xeragon Revenues and
              $8,800,000 by (z) $2,200,000;

                     (K) the term "Xeragon Business" shall mean the sale of
              custom or pre-manufactured synthetic RNA; provided, that the term
              "Xeragon Business" shall not include any products which (i) QIAGEN
              offers as of the date hereof or (ii) which QIAGEN may offer in the
              future which are not based on the XAG's Intellectual Property
              Rights;

                     (L) the term "Xeragon Revenues" shall mean, for the one
              year period ending on December 31, 2003, the aggregate of all
              revenues realized by QIAGEN directly from the Xeragon Business
              during such period, net of any trade, cash or quantity discounts
              or rebates, credits or allowances given or made and sales,
              transfer and other excise taxes and

                                       4

<PAGE>

              customs duties levied (including any tax such as a value added or
              similar tax or government charge); and

                     (M) the term "Xeragon Expense Percentage" shall mean, for
              the one-year period ending on December 31, 2003, the sum of the
              cost of goods sold and research and development expenses
              attributable to the Xeragon Business for such period expressed as
              a percentage of the aggregate of all operating expenses
              attributable to the Xeragon Business for such period.

              (iii)  Notwithstanding the foregoing, under no circumstances shall
    QIAGEN be obligated to issue any shares of QIAGEN Common Stock as
    Performance Shares to the extent that, such shares, when aggregated with the
    other shares of QIAGEN Common Stock previously issued pursuant to this
    Agreement, would result in the issuance of a number of shares of QIAGEN
    Common Stock that exceeds 657,143 shares of QIAGEN Common Stock (the
    "Issuance Limit"); provided, however, that the Issuance Limit shall be
    appropriately adjusted for any stock dividend, stock split, combination, or
    similar recapitalization occurring from and after the date of this
    Agreement.

       (b)    As of the Effective Time, each Company Share issued and
outstanding immediately prior to the Effective Time shall no longer be
outstanding, shall automatically be canceled and retired and shall cease to
exist, and each Company Shareholder shall cease to have any rights with respect
thereto, except the right to receive such Company Shareholder's portion of the
Merger Consideration in the form of Merger Shares upon surrender of such
certificate in accordance with Section 1.10 hereof and the contingent right to
receive the either the Performance Shares or, at the sole election of QIAGEN,
the Performance Cash, if any, in accordance with Section 1.18 hereof.

       (c)    The shares of QIAGEN Common Stock to be issued to the Company
Shareholders in connection with the Merger will be issued in a transaction
exempt from registration under the Securities Act of 1933, as amended (the
"Securities Act"), by reason of Section 4(2) thereof, will be "restricted
securities" which have not been registered under the Securities Act, and must be
held until they are either registered or an exemption from registration becomes
available for their resale. As provided in Section 6.3 hereof, QIAGEN shall use
its best efforts to prepare and file as promptly as practicable, and, in any
event, within thirty (30) days following the Effective Time, a registration
statement on Form F-3 with the Securities and Exchange Commission ("SEC")
covering the resale of the Merger Shares (the "Resale Registration Statement"),
and QIAGEN shall use reasonable efforts to cause the Resale Registration
Statement to become effective within ninety (90) days after the Effective Time
(the date of effectiveness of such Resale Registration Statement being referred
to herein as the "Registration Statement Effective Date").

       (d)    Within twenty-five (25) Business Days after the Closing Date,
QIAGEN will deposit in escrow certificates representing 15% of the Merger Shares
(the "Escrow Shares"), to be held in accordance with the terms of the Escrow
Agreement, a form of which is attached hereto as Exhibit C (the "Escrow
Agreement").

                                       5

<PAGE>

      1.7   Cancellation of Treasury  Shares. Each Company Share held in the
treasury of the Company immediately prior to the Effective Time shall be
canceled and extinguished without any conversion thereof.

      1.8   Capital Stock of Merger Sub. Each share of common stock, par value
$.001 per share, of Merger Sub (the "Merger Sub Common Stock"), issued and
outstanding immediately prior to the Effective Time shall be converted into and
exchanged for one validly issued, fully paid and non-assessable share of Common
Stock, par value $.0001 per share, of the Surviving Corporation. Each stock
certificate of Merger Sub evidencing ownership of any Merger Sub Common Stock
shall continue to evidence ownership of such shares of capital stock of the
Surviving Corporation.

      1.9   Fractional Shares. No fraction of a share of QIAGEN Common Stock
will be issued hereunder, but in lieu thereof each holder of Company Shares who
would otherwise be entitled to a fraction of a share of QIAGEN Common Stock
(after aggregating all fractional shares of QIAGEN Common Stock to be received
by such holder) shall receive from QIAGEN an amount of cash (rounded to the
nearest whole cent) equal to the product of such fraction multiplied by the
Closing Date Average (with respect to fractional Merger Shares) or the
Performance Average (with respect to fractional Performance Shares).

      1.10  Surrender of Certificates.

            (a)  QIAGEN to Provide QIAGEN Common Stock. Not later than
twenty-five (25) Business Days after the Effective Time, QIAGEN shall cause to
be delivered to the Exchange Agent, for exchange in accordance with this Article
1, the Merger Shares (exclusive of the Escrow Shares) issuable pursuant to
Section 1.6 in exchange for outstanding Company Shares paid pursuant to Section
1.6.

            (b)  Exchange Procedures. Promptly after the Effective Time, QIAGEN
shall cause the Exchange Agent to mail to each holder of record of a certificate
or certificates (the "Certificates") which immediately prior to the Effective
Time represented outstanding Company Shares whose shares were converted into the
right to receive shares of QIAGEN Common Stock pursuant to Section 1.6, (i) a
letter of transmittal in the form of Exhibit D hereto and instructions for use
in effecting the surrender of the Certificates in exchange for certificates
representing shares of QIAGEN Common Stock, (ii) a notice specifying the number
of whole Merger Shares to which such holder is entitled pursuant to Section 1.6
hereof and (iii) a notice specifying the amount of cash in lieu of the fraction
of a Merger Share, if any, to which such holder is entitled pursuant to Section
1.9 hereof. Upon surrender of a Certificate for cancellation to the Exchange
Agent, together with such letter of transmittal, duly completed and validly
executed in accordance with the instructions thereto, the holder of such
Certificate shall be entitled to receive in exchange therefor, (x) a certificate
representing the number of whole Merger Shares (less the shares of QIAGEN Common
Stock representing such holder's pro rata contribution to the Escrow Fund), and
(y) cash in lieu of fractional Merger Shares which such holder has the right to
receive pursuant to Section 1.9, and the Certificate so surrendered shall
forthwith be canceled. Until so surrendered, each outstanding Certificate that,
prior to the Effective Time, represented Company Shares will be deemed from and
after the Effective Time, for all corporate purposes, other than the payment of
dividends, to evidence the right to receive, upon surrender of such

                                       6

<PAGE>

Certificate, the number of full Merger Shares into which the Company Shares
represented by such Certificate shall have been so converted and the contingent
right to receive Performance Shares, or at the sole election of QIAGEN,
Performance Cash, if any, in the case of Merger Shares or Performance Shares
together with an amount in cash in lieu of fractional shares, if any, in
accordance with Section 1.9. Any portion of the shares of QIAGEN Common Stock
deposited with the Exchange Agent pursuant to this Section 1.10(b) which remains
undistributed to the holders of the Certificates representing Company Shares for
one hundred and eighty (180) days after the Effective Time shall be delivered to
QIAGEN, upon demand, and any holders of Company Shares who have not theretofore
complied with this Article 1 shall thereafter look only to QIAGEN for such
portion of QIAGEN Common Stock, any dividends or distributions with respect to
QIAGEN Common Stock and the amount of cash in lieu of the fraction of a share of
QIAGEN Common Stock, if any, to which such holders may be entitled.

      (c)   Distributions With Respect to Unexchanged Shares. No dividends or
other distributions declared or made after the Effective Time with respect to
QIAGEN Common Stock with a record date after the Effective Time will be paid to
the holder of any unsurrendered Certificate with respect to the shares of QIAGEN
Common Stock represented thereby until the holder of record of such Certificate
shall surrender such Certificate. Subject to applicable escheat Law, following
surrender of any such Certificate, there shall be paid to the record holder of
the certificates representing whole shares of QIAGEN Common Stock issued in
exchange therefor, without interest, at the time of such surrender, the amount
of dividends or other distributions with a record date after the Effective Time
theretofore paid with respect to such whole shares of QIAGEN Common Stock.

      (d)   Transfers of Ownership. If any certificate for shares of QIAGEN
Common Stock is to be issued in a name other than that in which the Certificate
surrendered in exchange therefor is registered, it will be a condition of the
issuance thereof that the Certificate so surrendered will be properly endorsed
and otherwise in proper form for transfer and that the Person requesting such
exchange will have paid to QIAGEN, or any agent designated by it, any transfer
or other taxes required by reason of the issuance of a certificate for shares of
QIAGEN Common Stock in any name other than that of the registered holder of the
certificate surrendered, or established to the satisfaction of QIAGEN or any
agent designated by it that such tax has been paid or is not payable.

      (e)   No Liability. Notwithstanding anything to the contrary in this
Agreement, none of the Exchange Agent, QIAGEN, Merger Sub or the Surviving
Corporation shall be liable to a holder of Company Shares for any QIAGEN Common
Stock or any amount properly paid to a public official pursuant to any
applicable abandoned property, escheat or similar Law.

      (f)   Withholding of Tax. QIAGEN or the Exchange Agent will be entitled to
deduct and withhold from the consideration otherwise payable pursuant to this
Agreement to any holder of Company Shares such amounts as QIAGEN (or any
Affiliate thereof) or the Exchange Agent are required to deduct and withhold
with respect to the making by such holder of payment required under the Code, or
any provision of federal, state, local or foreign tax law as a result of the
Merger. To the extent that amounts are so withheld by QIAGEN or the Exchange
Agent, such withheld amounts will be treated for all purposes of this Agreement
as having been paid to

                                       7

<PAGE>

the holder of the Company Shares in respect of whom such deduction and
withholding were made by QIAGEN.

      1.11  Further Ownership Rights in Company Shares. All shares of QIAGEN
Common Stock issued upon the surrender for exchange of Company Shares in
accordance with the terms of this Agreement (including any cash paid for
fractional shares paid in respect thereof) shall be deemed to have been issued
in full satisfaction of all rights pertaining to such Company Shares under this
Agreement other than the contingent right to receive Performance Shares, or at
the sole election of QIAGEN, Performance Cash, if any, and there shall be no
further registration of transfers on the records of the Surviving Corporation of
Company Shares which were outstanding immediately prior to the Effective Time.
If, after the Effective Time, Certificates are presented to the Surviving
Corporation for any reason, they shall be canceled and exchanged as provided in
this Article 1.

      1.12  Closing. Unless this Agreement shall have been terminated and the
transactions contemplated by this Agreement abandoned pursuant to the provisions
of Article 9, and subject to the provisions of Article 7, the closing of the
Merger (the "Closing") will take place at 10:00 a.m. (Eastern time) on a date
(the "Closing Date") to be mutually agreed upon by the parties, which date shall
be not later than the third Business Day after all the conditions set forth in
Article 7 shall have been satisfied (or waived in accordance with Article 7, to
the extent the same may be waived), unless another time and/or date is agreed to
in writing by the parties. The Closing shall take place at the offices of Mintz,
Levin, Cohn, Ferris, Glovsky and Popeo, P.C., One Financial Center, Boston,
Massachusetts, unless another place is agreed to in writing by the parties.

      1.13  Lost, Stolen or Destroyed Certificates. In the event any
Certificates shall have been lost, stolen or destroyed, the Exchange Agent shall
issue in exchange for such lost, stolen or destroyed certificates, upon the
making of an affidavit of that fact by the holder thereof, such shares of QIAGEN
Common Stock (and cash for fractional shares, if any), as may be required
pursuant to Sections 1.6 or 1.9; provided, however, that QIAGEN may, as a
condition precedent to the issuance or payment thereof, require the owner of
such lost, stolen or destroyed certificates to indemnify QIAGEN against any
claim that may be made against QIAGEN or the Exchange Agent with respect to the
Certificates alleged to have been lost, stolen or destroyed.

      1.14  Dissenters' Rights. All persons who have executed and delivered a
Stockholder Agreement shall have consented to the Merger and shall have
delivered their stock certificates in accordance with the terms hereof.
Notwithstanding anything in this Agreement to the contrary, any Company Shares
outstanding immediately prior to the Effective Time and held by a holder who has
not voted in favor of the Merger or delivered a valid, unrevoked proxy in favor
of the Merger, or consented thereto in writing and who has delivered written
notice to the Company objecting to the Merger and demanding payment for his
shares as required in accordance, and has otherwise complied, with the
applicable provisions of the ABCA ("Dissenting Shares"), shall not be converted
into the right to receive the QIAGEN Common Stock, unless and until such holder
fails to elect to dissent from the Merger or effectively withdraws or otherwise
loses his right to payment of the fair value of his shares under the provisions
of the ABCA. If, after the Effective Time, any such holder fails to perfect or
effectively withdraws or loses his right to such payment, such Dissenting Shares
shall thereupon be treated as if they had been converted as of

                                       8

<PAGE>

the Effective Time into the right to receive that portion of the Merger
Consideration to which such holder is entitled, without interest thereon. Any
amounts paid to holders of Dissenting Shares in an appraisal proceeding will be
paid by the Surviving Corporation out of its own funds and will not be paid by
QIAGEN or Merger Sub. The Company shall not, except with the prior written
consent of QIAGEN, make any payment with respect to any such demands or offer to
settle or settle any such demands.

      1.15  Further Assurances. If at any time after the Effective Time, the
Surviving Corporation shall consider or be advised that any deeds, bills of
sale, assignments or assurances or any other acts or things are necessary,
desirable or proper (a) to vest, perfect or confirm, of record or otherwise, in
the Surviving Corporation its right, title or interest in, to or under any of
the rights, privileges, immunities, powers, purposes, franchises, properties or
assets of the Company or Merger Sub, or (b) otherwise to carry out the purposes
of this Agreement, the Surviving Corporation and its proper officers and
directors or their designees shall be authorized to solicit in the name of the
Company or Merger Sub any third party consents or other documents required to be
delivered by any third party, to execute and deliver, in the name and on behalf
of the Company or Merger Sub, all such deeds, bills of sale, assignments and
assurances and do, in the name and on behalf of the Company or Merger Sub, all
such other acts and things necessary, desirable or proper to vest, perfect or
confirm its right, title or interest in, to or under any of the rights,
privileges, immunities, powers, purposes, franchises, properties or assets of
the Company or Merger Sub and otherwise to carry out the purposes of this
Agreement.

      1.16  Closing of Company Transfer Books. At the Effective Time, the stock
transfer books of the Company shall be closed and no transfer of Company Shares
shall thereafter be made. If, after the Effective Time, certificates
representing shares of Company Shares are presented to the Surviving
Corporation, they shall be canceled and presented to the Exchange Agent in
accordance with Section 1.10.

      1.17  Tax Consequences. It is intended by the parties hereto that the
Merger shall be treated for federal income tax purposes as a reorganization
within the meaning of Section 368(a)(1)(A) and 368(a)(2)(E) of the Code, and
that this Agreement shall be, and is hereby, adopted as a plan of reorganization
for purposes of Section 368 of the Code. The parties shall not take a position,
whether on any Tax Return or otherwise, that is inconsistent with this Section
1.17.

      1.18  Performance Calculation.

            (a)    As soon as practical after December 31, 2003, QIAGEN will
determine (i) the amount of Xeragon Revenues and (ii) the Xeragon Expense
Percentage, each to be determined in accordance with generally accepted
accounting principles, and shall deliver written notice of such determination to
Patrick Weiss as representative of the Company Shareholders (the "Dispute
Representative") at his address as set forth on the signature page hereto (or
such other address as he shall have furnished in writing to QIAGEN prior to such
time).

            (b)    If the Dispute Representative objects to QIAGEN's
determination of the Xeragon Revenues or Xeragon Expense Percentage, he shall
deliver to QIAGEN written notice

                                       9

<PAGE>

of such objection within 30 calendar days after his receipt of notice thereof (a
"Dispute Notice") setting forth, with specificity, the nature of his dispute and
his alternative calculation of the Xeragon Revenues and the Xeragon Expense
Percentage, as applicable. If the Dispute Representative does not timely deliver
to QIAGEN a Dispute Notice the Company Shareholders shall be deemed to have
agreed to QIAGEN's determination of the Xeragon Revenues and the Xeragon Expense
Percentage. If the Dispute Representative does timely deliver to QIAGEN a
Dispute Notice, QIAGEN and the Dispute Representative shall meet within 15
calendar days after QIAGEN's receipt of the Dispute Notice to attempt to resolve
any dispute referenced therein. Any dispute not able to be resolved within such
15 calendar day period shall be submitted to QIAGEN's independent accounting
representative, or another firm chosen by QIAGEN ("QIAGEN's Accountant"), and
another firm chosen by the Dispute Representative ("Shareholders' Accountant"
and together with QIAGEN's Accountant, (the "Accountants"), which shall endeavor
in good faith to resolve any disputed item(s). If the Accountants are unable to
resolve the disputed item(s) within thirty (30) calendar days after submission
to them, the Accountants shall together, within ten (10) Business Days
thereafter, appoint a representative from a "big five" accounting firm (other
than either of the Accountants) to arbitrate the dispute (the "Arbitrator").
QIAGEN and the Dispute Representative shall, within the next twenty (20)
calendar days thereafter, present their positions with respect to the disputed
item(s) to the Arbitrator together with such other materials as the Arbitrator
deems appropriate. The Arbitrator shall, after the submission of the evidentiary
materials, submit its written decision on each disputed item to QIAGEN and the
Dispute Representative. Any determination by the Arbitrator with respect to any
disputed item shall be final, binding and conclusive on each party to this
Agreement. QIAGEN and the Dispute Representative agree that the cost of the
Arbitrator shall be borne one-half (1/2) by QIAGEN and one-half (1/2) by the
Dispute Representative. QIAGEN shall be responsible for the cost of QIAGEN's
Accountant and the Dispute Representative shall be responsible for the cost of
the Shareholders' Accountant.

            (c) Upon final determination of the Xeragon Revenues and the
Expense Percentage (whether upon agreement of the parties, by the Accountants
or by the Arbitrator), QIAGEN shall, as soon as practical after such final
determination but subject to provisions of Section 1.6(a)(iii), issue and
deliver to the Company Shareholders either (A) the Performance Shares and cash
in lieu of any fractional Performance Shares in accordance with Section 1.6(a)
hereof or (B) the Performance Cash (rounded to the nearest $0.01 for each
Company Stockholder).

                                   ARTICLE 2
                  REPRESENTATIONS AND WARRANTIES OF THE COMPANY

         The Company hereby represents and warrants to QIAGEN and Merger Sub
that the statements contained in this Article 2 are correct and complete as of
the date of this Agreement and will be correct and complete at the Effective
Time, except as disclosed in the disclosure schedule dated the date hereof,
certified by the President and Chief Executive Officer of the Company and
delivered by the Company to QIAGEN and Merger Sub simultaneously herewith (which
disclosure schedule shall contain specific references to the representations and
warranties to which the disclosures contained therein relate, and an item on
such disclosure schedule shall be deemed to qualify only the particular
subsection or subsections specified for such item) (the "Company Disclosure
Schedule") as follows:

                                       10

<PAGE>

      2.1  Organization and Qualification; Subsidiaries.

           (a)  The Company is a corporation duly organized, validly existing
and in good standing under the laws of its jurisdiction of incorporation. The
Company has all the requisite corporate power and authority and is in possession
of all franchises, grants, authorizations, licenses, permits, easements,
consents, certificates, approvals and Orders (collectively, "Company Approvals")
necessary to own, lease and operate its properties and to carry on its business
as it is now being conducted, except where the failure to be so organized,
existing and in good standing or to have such power, authority and Company
Approvals would not, individually or in the aggregate, have a Material Adverse
Effect.

           (b)  The Company is duly qualified or licensed as a foreign
corporation to do business, and is in good standing, in each jurisdiction where
the character of the properties owned, leased or operated by it or the nature of
its activities makes such qualification or licensing necessary, except for such
failures to be so duly qualified or licensed and in good standing which would
not, individually or in the aggregate, have a Material Adverse Effect.

           (c)  The Company has no Subsidiaries and does not own any equity
interest in, or any interest convertible into or exchangeable or exercisable for
directly or indirectly, any equity or similar interest in, any Person.

           (d)  The ownership of XAG is described on Section 2.1 of the Company
Disclosure Schedule.

     2.2   Articles of Incorporation and By-laws. The Company has heretofore
furnished to QIAGEN a complete and correct copy of its Articles of Incorporation
and by-laws or equivalent organizational documents, as amended or restated to
the date hereof. Such Articles of Incorporation and by-laws, or equivalent
organizational documents of the Company, are in full force and effect. The
Company is not in violation of any of the provisions of its Articles of
Incorporation or by-laws or equivalent organizational documents.

     2.3   Capitalization.

           (a)  The authorized capital stock of the Company consists of
1,000,000 shares of common stock, $0.0001 par value per share (previously
defined herein as the "Company Shares"). Of such shares, (i) 1,000,000 Company
Shares are issued and outstanding; (ii) no Company Shares are held in the
treasury of the Company; (iii) no Company Shares are duly reserved for future
issuance and (iv) no options or warrants to purchase Company Shares are issued
and outstanding. Except as set forth above (x) no shares of voting or non-voting
capital stock, other equity interests, or other voting securities of the Company
were issued, reserved for issuance or outstanding and (y) there are no
outstanding stock appreciation rights of the Company and no outstanding limited
stock appreciation rights. All outstanding shares of capital stock of the
Company are duly authorized, validly issued, fully paid and non-assessable and
not subject to preemptive rights. None of the outstanding equity securities or
other securities of the Company was issued in violation of the Securities Act or
any other Law, Regulation or Order. There are no outstanding bonds, debentures,
notes or other indebtedness of the Company with voting rights (or convertible
into, or exchangeable for, securities with voting rights) on any

                                       11

<PAGE>

matters on which stockholders of the Company may vote. The Company Shares
owned by the Company Shareholders and being purchased pursuant to this Agreement
represent one hundred percent (100%) of the outstanding capital stock of the
Company of all classes.

           (b)  Section 2.3(b) of the Company Disclosure Schedule sets forth the
names of the owners of record of all Company Shares. Except as set forth in
Section 2.3(b) of the Company Disclosure Schedule there are no outstanding
securities, options, warrants, calls, rights, commitments, agreements,
arrangements, understandings or undertakings of any kind (contingent or
otherwise) to which the Company is a party or by which it is bound obligating
the Company to issue, deliver or sell, or cause to be issued, delivered or sold,
additional shares of its capital stock or other voting securities of the Company
or obligating the Company to issue, grant, extend or enter into any such
security, option, warrant, call, right, commitment, agreement, arrangement or
undertaking. There are no outstanding contractual obligations of the Company to
repurchase, redeem or otherwise acquire any shares of capital stock (or options
to acquire any such shares) of the Company.

           (c)  There are no voting trusts, proxies or other agreements,
commitments or understandings of any character to which the Company is a party
or by which the Company is bound with respect to the voting of any shares of
capital stock of the Company, except for the Voting Agreements. There are no
agreements, arrangements or commitments of any character (contingent or
otherwise) pursuant to which any person is or may be entitled or to cause the
Company or any successor corporation (including QIAGEN) to file a registration
statement under the Securities Act or which otherwise relate to the registration
of any securities of the Company or such successor corporation, except as
disclosed in Section 2.3(b) of the Company Disclosure Schedule.

     2.4   Authority Relative to this Agreement; Required Vote.

           (a)  The Company has all necessary corporate power and authority to
execute and deliver this Agreement, and each instrument required to be executed
and delivered by it at the Closing, to perform its obligations hereunder and
thereunder and to consummate the transactions contemplated hereby and thereby.
The execution and delivery by the Company of this Agreement, the performance of
its obligations hereunder, and the consummation by the Company of the
transactions contemplated hereby, have been duly and validly authorized by all
corporate action, and no other corporate proceedings on the part of the Company
are necessary to authorize this Agreement or to consummate the transactions so
contemplated. This Agreement has been duly and validly executed and delivered by
the Company and, constitutes the legal, valid and binding obligation of the
Company except to the extent that enforcement hereof may be limited by (A)
bankruptcy, insolvency, reorganization, moratorium or other similar laws now or
hereafter in effect relating to creditors' rights generally and (B) general
principles of equity (regardless of whether enforceability is considered in a
proceeding in equity or at law).

           (b)  The Board of Directors of the Company has directed that this
Agreement be submitted to the Company Shareholders for their approval and
authorization. The affirmative votes of holders of at least a majority of all
outstanding Company Shares are the only votes of the holders of any class or
series of capital stock of the Company necessary to approve and authorize this
Agreement, the Merger, the Related Agreements and the other transactions

                                       12

<PAGE>

contemplated hereby and thereby. The Company Shareholders beneficially own and
have the right to vote, in the aggregate, all of the total issued and
outstanding Company Shares.

     2.5   No Conflict; Required Filings and Consents.

           (a)  The execution and delivery by the Company of this Agreement or
any instrument required by this Agreement to be executed and delivered by the
Company at the Closing do not, and the performance by the Company of its
obligations under this Agreement or any instrument required by this Agreement to
be executed and delivered by the Company at the Closing, shall not (i) conflict
with or violate the Articles of Incorporation or by-laws or equivalent
organizational documents of the Company, (ii) conflict with or violate any Law,
Regulation or Order applicable to the Company or by which any of its properties
is bound or affected, (iii) result in any breach or violation of or constitute a
default (or an event that with notice or lapse of time or both would become a
default) under, or impair the Company's rights or alter the rights or
obligations of any third party under, or give to others any rights of
termination, amendment, acceleration or cancellation of, or result in the
creation of a Lien or encumbrance on any of the properties or assets of the
Company pursuant to, any note, bond, mortgage, indenture, contract, agreement,
lease, license, permit, franchise or other instrument or obligation to which the
Company is a party or by which the Company or any of its properties is bound or
affected, (iv) cause QIAGEN, the Merger Sub or the Company to become subject to,
or to become liable for the payment of, any Tax imposed by any state or local
Tax authority on the Company or any of its properties, or (v) cause any of the
assets owned by the Company to be reassessed or revalued by any state or local
Tax authority.

           (b)  The execution and delivery by the Company of this Agreement or
any instrument required by this Agreement to be executed and delivered by the
Company at Closing do not, and the performance by the Company of its obligations
under this Agreement and any instrument required by this Agreement to be
executed and delivered by the Company at Closing, shall not, require the Company
to obtain any consent or waiver of any Person or the consent, approval,
authorization or action by, license, waiver, qualification, Order or Permit,
observe any waiting period imposed by, or make any filing with or notification
to, any Court or Governmental Authority, domestic or foreign, except (A)
compliance with applicable requirements, if any, of the Securities Act, the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), state
securities laws ("Blue Sky Laws"), (B) the filing of appropriate Merger or other
documents as required by Delaware or Alabama Law, or (C) such other third party
consents, approvals, authorization, licenses, waivers, qualifications, Orders or
Permits set forth in Section 2.5(b) of the Company Disclosure Schedule.

     2.6   Material Agreements. Section 2.6 of the Company Disclosure Schedule
sets forth a true and complete list and a description of (i) all contracts,
licenses, agreements, permits and instruments to which the Company is a party or
by which it or any of its properties or assets may be bound, which are material
to the Company (in the case of contracts, licenses and agreements, "material"
meaning that the aggregate dollar value of obligations or commitments to or by
the Company thereunder shall be at least $5,000), (ii) each agreement pursuant
to which the Company or XAG has granted, or been granted, exclusive rights,
(iii) each agreement which has a term of one year or longer, and (iv) each
agreement which is related in any way to the Company's or XAG's Intellectual
Property Rights (collectively, the "Material Agreements").

                                       13

<PAGE>

Complete copies of all Material Agreements have been made available by the
Company to QIAGEN, and no oral Material Agreements exist. Each such Material
Agreement is in full force and effect, is a valid and binding obligation of the
Company and is enforceable against the Company in accordance with its terms, and
the Company does not have Knowledge that any Material Agreement is not a valid
and binding agreement of the other parties thereto. Each Material Agreement is
enforceable against the Company in accordance with its terms, and enforceable
against each other party thereto, in each case in each case except that the
enforcement thereof may be limited by (A) bankruptcy, insolvency,
reorganization, moratorium or other similar law now or hereafter in effect
relating to creditors' rights generally and (B) general principles of equity
(regardless of whether enforceability is considered in and there has not
occurred any material default by the Company or any other party thereto, which
remains unremedied. No condition exists or, event has occurred which (whether
with or without notice or lapse of time or both, or the happening or occurrence
of any other event) would result in a loss of rights or an acceleration of an
obligation or result in the creation of any Lien thereunder or pursuant thereto,
or would constitute a default by the Company or, to the Company's Knowledge, any
other party thereto under, or result in a right in termination of, any Material
Agreement. The Company is in compliance with the terms of the Company Approvals,
except where any failures to so comply would not, individually or in the
aggregate, have a Material Adverse Effect. The continuation, validity,
enforceability and effectiveness of each Material Agreement will not be affected
by the consummation of the transactions contemplated by this Agreement.
Furthermore, no party to a Material Agreement has repudiated any provision
thereof and communicated such repudiation to the Company, and there are no
negotiations pending or in progress to revise any material terms of any Material
Agreement.

     2.7   Compliance. The Company is not in conflict with, or in default or
violation of, any Law, Regulation or Order applicable to the Company or by which
its or any of its properties is bound or affected (other than any Law,
Regulation or Order relating to emissions, pollution or other environmental
matters, which are separately addressed in Section 2.21 hereof), except for any
such conflicts, defaults or violations which would not, individually or in the
aggregate, have a Material Adverse Effect. The Company has all requisite
licenses, permits, certificates, authorizations and approvals, including health
and safety and employee health and safety permits, from foreign, federal, state
and local authorities necessary to conduct its business as currently conducted
(collectively, the "Permits"), all of which Permits are set forth in Section 2.7
of the Company Disclosure Schedule, except where any failure to have such
Permits will not, individually or in the aggregate, have a Material Adverse
Effect. All of the Permits identified in Section 2.7 of the Company Disclosure
Schedule are in full force and effect no party thereto is in default under any
of such Permits and no event has occurred and no condition exists which, with
the giving of notice, the passage of time, or both, would constitute a default
thereunder. No action or claim is pending or, to the Company's Knowledge,
threatened, to revoke or terminate any Permit identified in Section 2.7 of the
Company Disclosure Schedule. The Company is not, nor has it been, in violation
of any Law, rule, Regulation, ordinance or court or administrative order
(including, without limitation, those relating to building, zoning, land use,
health and safety and employee health and safety matters), except where any such
violations would not, individually or in the aggregate, have a Material Adverse
Effect. The Company has not received any notice or communication from any
foreign, federal, state or local governmental or regulatory authority or
otherwise of any such violation and, to the Company's Knowledge, no such notice
or communication is threatened.

                                       14

<PAGE>

     2.8   Financial Statements. The Company has delivered to the QIAGEN: (a) an
unaudited balance sheet of the Company as of December 31, 2001 and the related
unaudited consolidated statements of income and cash flow for the fiscal year
then ended and (b) an unaudited balance sheet of the Company as of February 28,
2002 (the most recent of which is referred to as the "Company Balance Sheet").
Except as set forth on Section 2.8 of the Company Disclosure Schedule, such
financial statements (collectively, the "Company Financial Statements"), are
true, correct and complete and fairly present the financial condition, the
results of operations and cash flows of the Company as at the respective dates
of and for the periods referred to in such financial statements, all in
accordance with generally accepted accounting principles ("GAAP"), subject, in
the case of interim financial statements, to normal recurring year-end
adjustments and the absence of notes (the effect of which will not, individually
or in the aggregate, be materially adverse). Except as disclosed therein, the
Company Financial Statements reflect the consistent application of such
accounting principles throughout the periods involved. No financial statements
of any Person other than the Company are required by GAAP to be included in the
Company Financial Statements.

     2.9   Books and Records. The books of account, minute books, stock record
books, and other records of the Company, all of which have been made available
to QIAGEN, are complete and correct in all material respects. The Company
maintains a system of internal financial and accounting controls that was deemed
adequate by the Company's independent auditors based on their review of such
controls in connection with the most recent audit of the Company's financial
statements. The minute book of the Company contains accurate and complete
records of all meetings held of, and corporate action taken by, the
stockholders, the Boards of Directors, and committees of the Board of Directors
of the Company, and no meeting of any such stockholders, Board of Directors, or
committee has been held, or corporate action taken, for which minutes have not
been prepared and are not contained in such minute books.

     2.10  Accounts and Notes Receivable. All accounts and notes receivable
reflected in the Company Financial Statements and all accounts receivable
insofar as it represents income earned arising after December 31, 2001
(collectively, the "Company Accounts Receivable") have arisen in the ordinary
course of business of the Company, represent valid and enforceable obligations
due to the Company, and are not subject to and discount, set-off or
counter-claim. All such Company Accounts Receivable have been collected or, to
the Knowledge of the Company, are fully collectible in the ordinary course of
business of the Company in the aggregate amounts thereof in accordance with
their terms.

     2.11  Inventory. All inventory of the Company, whether or not reflected in
the Company Balance Sheet, consists of a quality and quantity usable and salable
in the ordinary course of business in all material respects, except for obsolete
items and items of below-standard quality, all of which have been written off or
written down to net realizable value in the Company Balance Sheet. All
inventories not written off have been priced at the lower of cost or market on a
first in, first out basis. The quantities of each item of inventory (whether raw
materials, work-in-process, or finished goods) are not excessive, but are
reasonable in the present circumstances of the Company.

     2.12  Customers and Distributors. Section 2.12 of the Company Disclosure
Schedule sets forth (i) all representatives and distributors of the Company's
products (whether pursuant to

                                       15

<PAGE>

commission, royalty or other arrangement) and (ii) a list of the Company's top
ten customers (determined by twelve-month trailing revenues from such customers)
(collectively, the "Customers and Distributors"). To the Knowledge of the
Company, the relationships of the Company with its Customers and Distributors
and its suppliers are good. There is no plan or intention of any such Customer,
Distributor, or supplier, and the Company has not received any written or oral
threat from any Customer, Distributor, or supplier, to terminate, cancel or
otherwise adversely modify its relationship with the Company or to decrease
materially or limit its services, supplies or materials to the Company or its
usage, purchase or distribution of the services or products of the Company.

     2.13  Absence of Certain Changes or Events.

           (a)  Since February 28, 2002, the Company has conducted its business
only in the ordinary and usual course and in a manner consistent with past
practice and, since such date, there has not been any (i) purchase, redemption,
retirement, or other acquisition by the Company from the Company Shareholders of
any shares of any such capital stock; or declaration or payment of any dividend
or other distribution or payment in respect of shares of capital stock; (ii)
payment or increase by the Company of any bonuses, salaries, or other
compensation to any stockholder, director, officer, or (except in the ordinary
course of business) employee or entry into any employment, severance, or similar
contract with any director, officer, or employee; (iii) adoption of, or increase
in the payments to or benefits under, any Company Benefit Plan (as defined in
Section 2.16(a)); (iv) damage to or destruction or loss of any asset or property
of the Company, whether or not covered by insurance, that is reasonably likely
to have a Material Adverse Effect; (v) entry into, termination of, or receipt of
notice of termination of (A) any license, distributorship, dealer, sales
representative, joint venture, credit, or similar agreement, or (B) any Material
Agreement or transaction involving a total remaining commitment by or to the
Company of at least $5,000; (vii) sale (other than sales of inventory in the
ordinary course of business), lease, or other disposition of any asset or
property of the Company or mortgage, pledge, or imposition of any Lien on any
material asset or property of the Company, including the sale, lease, or other
disposition of any of the Intellectual Property Rights; (vii) cancellation or
waiver of any claims or rights with a value to the Company in excess of $5,000;
(viii) material change in the accounting methods used by the Company; (ix)
incurrence of any indebtedness for borrowed money or capital lease obligations
outside the ordinary course of business; (x) guaranty of any indebtedness of
another Person; (xi) acquisition by merger or consolidation with, or by
purchasing a substantial equity interest in, or by any other manner, any
business or any Person; (xii) acceleration, termination (other than end-of-term
expirations), modification, cancellation, declaration of a default under or
indication of an intent to terminate any Material Agreement (or series of
related Material Agreements) involving more than $5,000 to which the Company is
a party or by which it is bound; (xiii) any capital expenditure (or series of
related capital expenditures) either involving more than $5,000 or outside the
ordinary course of business; (xiv) delay or postponement of the collection of
accounts receivable or the payment of accounts payable and other liabilities
outside the ordinary course of business; (xvi) loan to, or, except in the
ordinary course of business, entry into any other transaction with, any of its
directors, officers and employees; (xvi) entry into any transaction other than
in the ordinary course of business; (xvii) agreement, whether oral or written,
by the Company to do any of the foregoing; and (xviii) any other change, event,
development or circumstance affecting the

                                       16

<PAGE>

Company which, individually or in the aggregate, has, or is reasonably likely to
have, a Material Adverse Effect.

           (b)  Since December 31, 2001, there has not been any change by the
Company in its accounting methods, principles or practices, any revaluation by
the Company of any of its assets, including, writing down the value of inventory
or writing off notes or accounts receivable other than in the ordinary course of
business, or any condition, event or occurrence which could reasonably be
expected to prevent, hinder or materially delay the ability of the Company to
consummate the transactions contemplated by this Agreement.

     2.14  No Undisclosed Liabilities. The Company has no liabilities or
obligations of any nature (whether absolute, accrued, fixed, contingent or
otherwise), except (a) liabilities or obligations reflected in the Company
Balance Sheet, (b) liabilities or obligations incurred in the ordinary course of
business consistent with past practice since February 28, 2002 which are not,
and will not have, individually or in the aggregate, a Material Adverse Effect
on the Company and (c) liabilities or obligations which are not and will not
have, individually or in the aggregate, a Material Adverse Effect on the
Company.

     2.15  Absence of Litigation. There is no Litigation pending against the
Company or, to the Company's Knowledge, against any licensors of Intellectual
Property to the Company, or, to the Company's Knowledge, threatened against the
Company and there is no basis for such Litigation. The Company is not subject to
any outstanding Claim or Order which, individually or in the aggregate, has, or
in the future might have, a Material Adverse Effect or would prevent, hinder or
delay the Company from consummating the transactions contemplated by this
Agreement.

     2.16  Employee Benefit Plans.

           (a)  The Company has no deferred compensation, incentive
compensation, stock purchase, restricted stock option and other equity
compensation plan, "welfare" plan, fund or program (within the meaning of
Section 3(1) of the Employee Retirement Income Security Act of 1974, as amended
("ERISA"); "pension" plan, fund or program (within the meaning of Section 3(2)
of ERISA); or any other employee benefit plan, fund, program, agreement or
arrangement, including but not limited to vacation plans, cafeteria plans,
educational assistance or reimbursement plans, spending account plans (for
medical expenses, dependent care expenses, or other expenses), severance, golden
parachute, termination, supplemental unemployment, plant closing or similar
benefits, active health or life or other post-employment welfare or insurance
plans, bonus or performance based compensation plans or arrangements,
supplemental executive retirement plans or other supplemental or excess benefit
plans in each case, that is sponsored, maintained or contributed to or required
to be contributed to by the Company, any trade or business (whether or not
incorporated) which is a member of a controlled group or which is under common
control with the Company within the meaning of Section 414 of the Code or which
could be deemed a "single employer" within the meaning of Section 4001(b) of
ERISA (an "ERISA Affiliate"), or to which the Company or an ERISA Affiliate is a
party, whether written or oral, for the benefit of any officer, director,
employee or former employee of the Company or any of its ERISA Affiliates,
whether or not such plan has been terminated ("Company Benefit Plans").

                                       17

<PAGE>

           (b)  No liability under Title IV or Section 302 of ERISA has been
incurred by the Company or any ERISA Affiliate that has not been satisfied in
full, and no condition exists that presents a risk to the Company or any ERISA
Affiliate of incurring any such liability.

           (c)  The execution, delivery and performance, and consummation of the
transactions contemplated by, this Agreement and the Related Agreements will not
(i) entitle any current or former employee or officer of the Company or any
ERISA affiliate to severance pay, unemployment compensation or any other
payment, except as expressly provided in this Agreement, (ii) accelerate the
time of payment or vesting, or increase the amount of compensation due any such
employee or officer, or (iii) accelerate the vesting of any stock option or of
any shares of restricted stock.

           (d)  Section 2.16(d) of the Company Disclosure Schedule contains a
complete and accurate list of the following information for each retired
employee or director of the Company, or their dependents, receiving benefits or
scheduled to receive benefits in the future: name, pension benefit, pension
option election, retiree medical insurance coverage, retiree life insurance
coverage, and other benefits.

     2.17  Employment and Labor Matters.

           (a)  Section 2.17(a) of the Company Disclosure Schedule identifies
all employees and consultants employed or engaged by the Company or XAG and sets
forth each such individual's rate of pay or annual compensation (and the
portions thereof attributable to salary and bonuses, respectively), job title
and date of hire. There are no employment, consulting, severance pay,
continuation pay, termination or indemnification agreements or other similar
agreements of any nature (whether in writing or not) between the Company or XAG
and any current or former stockholder, officer, director, employee, or any
consultant. No individual will accrue or receive additional benefits, service or
accelerated rights to payments under any Company Benefit Plan, including the
right to receive any parachute payment, as defined in Section 280G of the Code,
or become entitled to severance, termination allowance or similar payments as a
result of the transaction contemplated herein that could result in the payment
of any such benefits or payments. Neither the Company nor XAG is delinquent in
payments to any of its employees or consultants for any wages, salaries,
commissions, bonuses or other compensation for any services. To the Company's
Knowledge, none of the Company's employment policies or practices are currently
being audited or investigated by any Governmental Authority. There are no
pending, or to the Company's Knowledge, threatened, claims, charges, actions,
lawsuits or proceedings alleging claims against the Company or XAG brought by or
on behalf of any employee or other individual or any Governmental Authority with
respect to employment practices, and no facts or circumstances exist that could
give rise to any such claims, charges, actions, lawsuits or proceedings.

           (b)  There are no controversies pending or, to the Company's
Knowledge, threatened, between the Company or XAG and any of its employees, and
employee relations are, in general, considered to be good; the Company is not a
party to any collective bargaining agreement or other labor union contract
applicable to persons employed by the Company nor are there any activities or
proceedings of any labor union or by any employees to organize any such
employees of the Company; during the past five years there have been no strikes,
slowdowns,

                                       18

<PAGE>

work stoppages, lockouts, or threats thereof, by or with respect to any
employees of the Company. The Company does not have nor at the Closing will the
Company have any obligation under the Worker Adjustment and Retraining
Notification Act (the "WARN Act"). The Company is in compliance with all
applicable provisions of applicable state, local, federal and foreign
employment, wage and hour, labor and other applicable laws, except where any
failures to be in compliance therewith would not, individually or in the
aggregate, have a Material Adverse Effect.

     2.18  Absence of Restrictions on Business Activities.

           (a)  There is no Material Agreement or Order binding upon the Company
or any of its properties which has had or could reasonably be expected to have
the effect of prohibiting or materially impairing any business practice of the
Company or the conduct of business by the Company as currently conducted. The
Company is not subject to any non-competition or similar restriction on its
business. The Company has not at any time entered into, or agreed to enter into,
any interest rate swaps, caps, floors or option agreements or any other interest
rate risk management arrangement or foreign exchange contracts.

           (b)  No employee or director of the Company is a party to, or is
otherwise bound by, any agreement or arrangement, including any confidentiality,
non-competition, or proprietary rights agreement, between such employee or
director and any other Person ("Proprietary Rights Agreement") that in any way
adversely affects or will adversely affect (i) the performance of his or her
duties as an employee or director of the Company, or (ii) the ability of the
Company to conduct its business, including any Proprietary Rights Agreement with
the Company by any such employee or director. To the Knowledge of the Company,
no director, officer, or other key employee of the Company intends to terminate
his or her employment with the Company.

           (c)  The Company acknowledges that it has been informed by QIAGEN
that after the Closing QIAGEN intends to move the business operations of the
Company to its U.S. headquarters in Germantown, Maryland.

     2.19  Title to Assets; Leases.

           (a)  Except as described in Section 2.19 of the Company Disclosure
Schedule, the Company owns no real property. Section 2.19 of the Company
Disclosure Schedule sets forth a true and complete list of all real property
leased by the Company and the aggregate monthly rental or other fee payable
under such lease. The Company has good and marketable title to all of their
respective properties and assets, free and clear of all Liens, charges and
encumbrances, except Liens for Taxes (as defined below) not yet due and payable
and such Liens or other imperfections of title, if any, as do not materially
detract from the value of or interfere with the present use of the property
affected thereby. All leases pursuant to which the Company leases real or
personal property from others are valid and effective in accordance with their
respective terms, and there is not, under any of such leases, any existing
material default or event of material default (or event which with notice or
lapse of time, or both, would constitute a material default and in respect of
which the Company has not taken adequate steps to prevent

                                       19

<PAGE>

such a default from occurring or to cure such default) by the Company or, to the
Company's Knowledge, any third party.

           (b)  The Company has good and marketable title to or a valid
leasehold interest in all of the properties and assets that are necessary to the
conduct of the business of the Company as it is currently being conducted,
including all of the properties and assets reflected in the Company Balance
Sheet, other than any such properties or assets that have been sold or otherwise
disposed of in the ordinary course of business since February 28, 2002.

           (c)  The buildings, plants, structures, and equipment of the Company
are structurally sound, are in good operating condition and repair in all
material respects, and are adequate for the uses to which they are being put,
and none of such buildings, plants, structures, or equipment is in need of
maintenance or repairs except for ordinary, routine maintenance and repairs that
are not material in nature or cost. The building, plants, structures, and
equipment of the Company are sufficient for the continued conduct of the
Company's business after the Closing in substantially the same manner as
conducted prior to the Closing.

     2.20  Taxes. For purposes of this Agreement, "Tax" or "Taxes" shall mean
taxes and governmental impositions of any kind in the nature of (or similar to)
taxes, payable to any federal, state, local or foreign taxing authority,
including but not limited to those on or measured by or referred to as income,
franchise, profits, gross receipts, capital ad valorem, custom duties,
alternative or add-on minimum taxes, estimated, environmental, disability,
registration, value added, sales, use, service, real or personal property,
capital stock, license, payroll, withholding, employment, social security,
workers' compensation, unemployment compensation, utility, severance,
production, excise, stamp, occupation, premiums, windfall profits, transfer and
gains taxes, and interest, penalties and additions to tax imposed with respect
thereto; and "Tax Returns" shall mean returns, reports and information
statements, including any schedule or attachment thereto, with respect to Taxes
required to be filed with the Internal Revenue Service or any other governmental
or taxing authority or agency, domestic or foreign, including consolidated,
combined and unitary tax returns.

           (a)  All federal, state, local and foreign Tax Returns required to be
filed (taking into account extensions) by or on behalf of the Company, and each
affiliated, combined, consolidated or unitary group of which the Company is or
has been a member, have been timely filed, and all such Tax Returns are true,
complete and correct.

           (b)  Except as set forth on Section 2.20 of the Company Disclosure
Schedule, all Taxes payable by or with respect to the Company have been timely
paid, or are adequately reserved for (other than a reserve for deferred Taxes
established to reflect timing differences between book and Tax treatment) in
accordance with GAAP on the Company Balance Sheet. No deficiencies for any Taxes
have been proposed, asserted or assessed either orally or in writing against the
Company that are not adequately reserved for in accordance with GAAP on the
respective Company Balance Sheet. All assessments for Taxes due and owing by or
with respect to the Company with respect to completed and settled examinations
or concluded litigation have been paid. The Company has not incurred a Tax
liability from the date of the latest Company Balance Sheet other than a Tax
liability in the ordinary course of business.

                                       20

<PAGE>

               (c)   The Company has not requested, or been granted any waiver
of any federal, state, local or foreign statute of limitations with respect to,
or any extension of a period for the assessment of, any Tax. No extension or
waiver of time within which to file any Tax Return of, or applicable to, the
Company has been granted or requested, except as set forth in Section 2.20 of
the Company Disclosure Schedule, which extension or waiver has not since
expired.

               (d)   The Company is not and has never been (nor does the Company
have any liability for unpaid Taxes because it once was) a member of an
affiliated, consolidated, combined or unitary group, and the Company is not a
party to any Tax allocation or sharing agreement or liable for the Taxes of any
other party, as transferee or successor, by contract, or otherwise.

               (e)   Prior to the date hereof, the Company has provided QIAGEN
with written schedules setting forth the taxable years of the Company for which
the statutes of limitations with respect to foreign, federal and material state
income Taxes have not expired, and with respect to foreign, federal and material
state income Taxes, those years for which examinations have been completed and
those years for which examinations are presently being conducted.

               (f)   Based on its current income, assets and activities, the
Company does not believe that it presently is a "foreign investment company" as
such term is defined in Section 1246(b) of the Code.

               (g)   The Company is not presently and has not been a "passive
foreign investment company" as such term is defined in Section 1297(a) of the
Code.

               (h)   The Company is not presently and has not been at any time
during the last five years a "controlled foreign corporation" as such term is
defined in Section 957(a) of the Code.

               (i)   The Company has not made any payments, is not obligated to
make any payments, and is not a party to any agreements that under any
circumstances could obligate it to make any payments that will not be deductible
under Section 280G of the Code.

               (j)   No unsatisfied deficiency, delinquency or default for any
Tax has been claimed, proposed or assessed against or with respect to the
Company, nor has the Company received notice of any such deficiency, delinquency
or default which, in any such case, may have a Material Adverse Effect.

               (k)   The Company has not been a United States real property
holding corporation within the meaning of Section 897(c)(2) of the Code during
the applicable period specified in Section 897(c)(1)(A)(ii) of the Code.

               (l)   The Company has complied with all applicable Laws relating
to the payment and withholding of Taxes (including, without limitation,
withholding of Taxes pursuant to Sections 1441, 1442 and 3406 of the Code or
similar provisions under any foreign Laws) and has, within the time and in the
manner required by Law, withheld from employee wages and paid over to the proper
Governmental Authorities all amounts required to be so withheld and paid over
under all applicable Laws.

                                       21

<PAGE>

               (m)   Section 2.20(m) of the Company Disclosure Schedule sets
forth: (i) the net operating loss ("NOL") and (ii) capital loss carry forwards
for foreign and federal income Tax purposes of the Company through the taxable
year ended December 31, 2001.

               (n)   The NOLs of the Company are not subject to Section 382 or
269 of the Code, Treasury Regulation Section 1.1502-21T(c), or any similar
provisions or regulations otherwise limiting the use of the NOLs of the Company.

               (o)   No property of the Company is "tax-exempt use property" as
such term is defined in Section 168 of the Code.

               (p)   The Company has never made an election under Section 341(f)
of the Code.

       2.21    Environmental Matters.

               (a)   The Company is and has been in compliance with all
applicable Environmental Laws;

               (b)   The Company has obtained all Permits relating to the
business required by any applicable Environmental Law and all environmental
permits relating to the business of the Company and all such permits are in full
force and effect in all respects; the environmental Permits do not materially
limit or affect the processes, methods, capacity or operating hours of the
persons carrying on the business of the Company as it is currently carried on;

               (c)   The Company has not, and the Company has no Knowledge of
any other Person who has, caused any unlawful or improper release, threatened
release or disposal of any Hazardous Material at any properties or facilities
previously or currently owned, leased or occupied by the Company;

               (d)   The Company has no Knowledge that any of the Company's
facilities are adversely affected by any release, threatened release or disposal
of a Hazardous Material originating or emanating from any other property;

               (e)   The Company (i) has no liability for response or corrective
action, natural resources damage, or any other harm pursuant to any
Environmental Law, (ii) is not subject to, has notice or Knowledge of, or is
required to give any notice of any Environmental Claim involving an allegation
against the Company or any properties or facilities of the Company or (iii) has
no Knowledge of any condition or occurrence which could reasonably be expected
to form the basis of an Environmental Claim against the Company or any of its
properties or facilities;

               (f)   The Company is not subject to any, and the Company has no
Knowledge of any, imminent restriction on the ownership, occupancy, use or
transferability of their properties and facilities arising from any (i)
Environmental Law or (ii) release, threatened release or disposal of any
Hazardous Material; and

                                       22

<PAGE>

               (g)   There is no Environmental Claim pending, or, to the
Company's Knowledge, threatened, against the Company or, to the Company's
Knowledge, against any Person whose liability for any Environmental Claim the
Company has or may have retained or assumed either contractually or by operation
of law and no basis exists for any Environmental Claim against the Company. No
material capital expenditure is currently required for the Company in relation
to environmental matters in order to comply with, extend, renew or obtain any
environmental permit or comply with Environmental Laws. Copies of all
environmental audits and other assessments, reviews and reports have been
previously provided to QIAGEN.

       2.22    Intellectual Property.

               (a)   Section 2.22(a) of the Company Disclosure Schedule sets
forth a true, correct and complete list of all of the Company's and XAG's United
States and foreign (i) patents and patent applications (the "Patents"), (ii)
registered and unregistered trademarks and trademark applications, including
material Internet domain name registrations (the "Trademarks"), (iii) service
marks, service mark applications and trade names (the "Tradenames"), (iv)
copyright registrations and copyright applications (the "Copyrights"), and (v)
licenses presently used by the Company, indicating for each, the applicable
jurisdiction, registration number (or applicable number), and date issued or
filed, as applicable, with respect to (i), (ii), (iii), and (iv) above and
including the terms of such licenses (all of which, together with patent rights,
trade secrets, confidential business information, formulas, processes, invention
records, procedures, research and development activity reports, laboratory
notebooks, copyrights, license rights and trademark rights which relate to or
are used or held for use in connection with the business of the Company or XAG,
are collectively referred to as, the "Intellectual Property Rights"). Copies of
all licenses listed in (v) above have been previously provided or made available
to QIAGEN. The Intellectual Property Rights are sufficient for the conduct of
the Company's business as presently conducted.

               (b)   Section 2.22(b) of the Company Disclosure Schedule sets
forth a true, correct and complete list, and where appropriate, a description of
all Intellectual Property Rights set forth in Section 2.22(a) of the Company
Disclosure Schedule to which the Company's rights are not exclusive, excluding
all Intellectual Property Rights which the Company has the right to use under a
shrinkwrap or similar mass marketing license. Except as otherwise disclosed in
Section 2.22(b) of the Company Disclosure Schedule and excluding all
Intellectual Property Rights subject to a shrinkwrap or similar mass marketing
license, the Company exclusively owns or has the exclusive right to use all of
the Intellectual Property Rights listed in Section 2.22(a) of the Company
Disclosure Schedule. It is not and will not be necessary to utilize any
inventions of any of its employees or consultants (or individuals it currently
intends to hire) made prior to their employment by the Company.

               (c)   All Trademarks, Patents, Tradenames and Copyrights are
currently in compliance with all legal requirements (including the timely
post-registration filing of affidavits of use and incontestability and renewal
applications with respect to Trademarks, and the payment of filing, examination
and maintenance fees and proof of working or use with respect to Patents), and
are, to the Company's Knowledge, valid and enforceable. No Trademark has been or
is now involved in any cancellation and, to the Company's Knowledge, no such
action is threatened with respect to any of the Trademarks. No Patent has been
or is now involved in any

                                       23

<PAGE>

interference, reissue, re-examination or opposition proceeding. To the Company's
Knowledge, there are no potentially conflicting trademarks or potentially
interfering patents of any third party. The Company has discussed with QIAGEN's
counsel the content of all reviews, assessments or analyses (whether written or
oral) pertaining to the Company's ability to use Patents (whether owned or
licensed).

               (d)   Except as disclosed on Section 2.22(d) of the Company
Disclosure Schedule:

                     (i)    The Company owns free and clear of all Liens, all
      owned Intellectual Property Rights, and has a valid and enforceable right
      to use in accordance with the applicable license agreement, if any, all of
      the Intellectual Property Rights licensed to the Company and used in the
      Company's business;

                     (ii)   The Company has taken all necessary steps to protect
      and preserve the Intellectual Property Rights which the Company owns or
      has licensed;

                     (iii)  The conduct of the Company's businesses as currently
      conducted, or as contemplated to fulfill the Company's business plan for
      fiscal year 2002, does not and will not infringe upon any intellectual
      property rights owned or controlled by any third party;

                     (iv)   There is no Litigation pending or, to the Company's
      Knowledge, threatened, nor has the Company received any written
      communication of, and there is no basis for, a claim against it (1)
      alleging that the Company's or XAG's activities, products, publications or
      the conduct of its businesses infringes upon, violates, or constitutes the
      unauthorized use of the intellectual property rights of any third party,
      or (2) challenging the ownership, use, validity or enforceability of any
      Intellectual Property Rights of the Company or XAG;

                     (v)    No third party is misappropriating, infringing,
      diluting, or violating any Intellectual Property Rights of the Company or
      XAG, and no such claims have been brought against any third party by the
      Company or XAG, and the Company has not knowingly misappropriated the
      trade secrets of any third party; and

                     (vi)   The execution, delivery and performance by the
      Company of this Agreement, and the consummation of the transactions
      contemplated hereby will not result in the loss or impairment of or give
      rise to any right of any third party to terminate any of the Company's
      rights to own any of the Intellectual Property Rights owned by the Company
      or to use any Intellectual Property Rights licensed to the Company
      pursuant to the license agreements, nor require the consent of any
      Governmental Authority or third party in respect of any such Intellectual
      Property Rights.

               (e)   All Trademarks have been in continuous use by the Company
or XAG. To the Company's Knowledge (i) there has been no prior use of such
Trademarks by any third party which would confer upon said third party superior
rights in such trademarks, and (ii) the registered Trademarks have been
continuously used in the form appearing in, and in connection with the goods and
services listed in, their respective registration certificates.

                                       24

<PAGE>

               (f)   The Company has taken all reasonable steps in accordance
with normal industry practice to protect the Company's rights in confidential
information and trade secrets of the Company. Without limiting the foregoing and
except as would not be materially adverse to the Company, the Company has and
enforces a policy of requiring each employee, consultant and contractor to
execute proprietary information, confidentiality and assignment agreements
substantially consistent with the Company's standard forms thereof. All of the
Company's employees, consultants and contractors have executed such a
proprietary information, confidentiality and assignment agreement. Except under
confidentiality obligations, there has been no material disclosure by the
Company of the Company's material confidential information or trade secrets.

       2.23    Insurance.

               (a)   Section 2.23 of the Company Disclosure Schedule sets forth
a true and complete list of all insurance policies and fidelity bonds covering
the assets, business, equipment, properties, operations, employees, officers and
directors of the Company including: (i) a summary of the loss experience under
each policy; (ii) a statement describing each claim under an insurance policy
for an amount in excess of $5,000, which sets forth: (A) the name of the
claimant; (B) a description of the policy by insurer, type of insurance, and
period of coverage; and (C) the amount and a brief description of the claim; and
(iii) a statement describing the loss experience for all claims that were
self-insured, including the number and aggregate cost of such claims. There is
no claim by the Company pending under any of such policies or bonds as to which
coverage has been questioned, denied or disputed by the underwriters of such
policies or bonds. All premiums payable under all such policies and bonds have
been paid, and the Company is otherwise in full compliance with the terms of
such policies and bonds (or other policies and bonds providing substantially
similar insurance coverage). Such policies of insurance and bonds are of the
type and in amounts customarily carried by Persons conducting businesses similar
to those of the Company and reasonable in light of the assets of the Company. As
of the date hereof, the Company has not received notice of any, and to Company's
Knowledge, there is no threatened, termination of or material premium increase
with respect to any of such policies or bonds.

               (b)   All policies to which the Company is a party or that
provide coverage to either the Company, or any director or officer of the
Company: (A) are valid, outstanding, and enforceable; (B) are issued by an
insurer that is financially sound and reputable; (C) taken together, provide
adequate insurance coverage for the assets and the operations of the Company for
all risks normally insured against by a Person carrying on the same business as
the Company; (D) are sufficient for compliance with all Laws and Material
Agreements to which the Company is a party or by which it is bound; (E) will
continue in full force and effect following the consummation of the transactions
contemplated by this Agreement; and (F) do not provide for any retrospective
premium adjustment or other experienced-based liability on the part of the
Company.


               (c)   The Company has not received (A) any refusal of coverage
from the issuer of any insurance policy of the Company or any notice that a
defense will be afforded with reservation of rights, or (B) any notice of
cancellation or any other indication that any insurance

                                       25

<PAGE>

policy is no longer in full force or effect or will or will not be renewed or
that the issuer of any policy is not willing or able to perform its obligations
thereunder.

               (d)   The Company has paid all premiums due, and has otherwise
performed all of its respective obligations, under each policy to which the
Company is a party or that provides coverage to the Company or a director
thereof.

               (e)   The Company has given notice to the insurer of all claims
that may be insured thereby.

        2.24   Brokers. No broker, financial advisor, finder or investment
banker or other Person is entitled to any broker's, financial advisor's,
finder's or other fee or commission in connection with the transactions
contemplated by this Agreement based upon arrangements made by or on behalf of
the Company.

        2.25   Certain Business Practices. Neither the Company nor any director,
officer, employee or agent of the Company has (i) used any funds for unlawful
contributions, gifts, entertainment or other unlawful payments relating to
political activity, (ii) made any unlawful payment to any foreign or domestic
government official or employee or to any foreign or domestic political party or
campaign or violated any provision of the Foreign Corrupt Practices Act of 1977,
as amended, (iii) consummated any transaction, made any payment, entered into
any agreement or arrangement or taken any other action in violation of Section
1128B(b) of the Social Security Act, as amended, or (iv) made any other unlawful
payment.

        2.26   Interested Party Transactions. The Company is not indebted to any
director, officer, employee or agent of the Company (except for amounts due as
normal salaries and bonuses and in reimbursement of ordinary expenses), and no
such Person is indebted to the Company.

        2.27   Disclosure. The representations and warranties of the Company
contained in this Agreement (including the Company Disclosure Schedule) do not
contain, and will not contain at the Closing Date, any untrue statement of a
material fact, and do not omit, and will not omit at the Closing Date, to state
any material fact necessary to make such representations and warranties, in
light of the circumstances under which they are made, not misleading. There is
no fact known to the Company that has not been disclosed to QIAGEN and Merger
Sub in this Agreement (including in the Company Disclosure Schedule) that is
reasonably likely to have a Material Adverse Effect.

                                    ARTICLE 3
                 REPRESENTATIONS AND WARRANTIES OF THE FOUNDERS

        Each of Mr. Weiss and Mr. Pitsch (each a "Founder" and collectively, the
"Founders") severally represents and warrants to QIAGEN as follows:

        3.1    Conflicting Agreements. The Founder is not, and will not be as a
result of the nature of the business conducted or proposed to be conducted by
the Surviving Corporation or QIAGEN after the Closing or for any other reason,
in violation of (i) any fiduciary or confidential relationship, (ii) any term of
any contact or covenant (either with the Company or

                                       26

<PAGE>

with another entity) relating to employment, patents, assignment of inventions,
proprietary information disclosure, non-competition or non-solicitation, or
(iii) any other contract or agreement, or any judgment, decree or order of any
court or administrative agency, relating to or affecting the Founder to be
employed or retained as a consultant by the Company. No such relationship, term,
contract, agreement, judgment, decree, or order conflicts with the Founder's
obligations to use his best efforts to promote the interests of the Company, nor
does the execution and delivery of this Agreement or the Related Agreements, nor
the carrying on of the Company's business as an officer, consultant or employee
of the Company, conflict with any such relationship, term, contract, agreement,
judgment, decree or order.

        3.2    Litigation. There is no Litigation pending or, to the best of the
Founder's knowledge, threatened against the Founder, and, to the best of the
Founder's knowledge, there is no basis for any such Litigation.

        3.3    Intellectual Property.


               (a)   Set forth on Section 3.4 of the Company Disclosure Schedule
is a list and brief description of all Intellectual Property Rights assigned to
the Company or XAG by the Founder, proposed to be assigned to the Company or XAG
by the Founder, or licensed to the Company or XAG by the Founder (or any entity
affiliated with the Founder) (collectively, "Founder Intellectual Property").

               (b)   there is no adverse claim or, to the best of the Founder's
knowledge, any threatened claim that would interfere with the Surviving
Corporation or QIAGEN's exclusive right to use the Founder Intellectual
Property. No product, service or process presently used or proposed to be
manufactured, marketed, offered, sold or used by the Company which was
originally Founder Intellectual Property will violate any license or infringe on
any intellectual property rights of any other person; and neither the Company's
intellectual property rights in the Founder Intellectual Property nor the
operation of the Company's business nor proposed operation of the Surviving
Corporation's business shall conflict with the asserted rights of others, nor
does there exist any known basis for any such conflict. No claim is pending or
threatened to the effect that any Founder Intellectual Property is invalid or
unenforceable by the Company, and none of the Founder Intellectual Property may
be invalid. Except as set forth in Section 3.4 of the Company Disclosure
Schedule, the Company has no obligation to compensate any person for the use of
any of the Founder Intellectual Property.

        3.4    Indemnification by Founders.

               (a)   Each of the Founders shall, with respect to the
representations, warranties and agreements made by him in this Article 3 jointly
and severally with the Company and the Company Shareholders as provided in
Article 8, indemnify, defend and hold QIAGEN harmless against all liability,
loss or damage, together with all reasonable costs and expenses related thereto
(including legal and accounting fees and expenses), arising from the untruth,
inaccuracy or breach of any such representations, warranties or agreements of
the Founder. Without limiting the generality of the foregoing, QIAGEN shall be
deemed to have suffered liability, loss or damage as a result of the material
untruth, inaccuracy or breach of any such representations or

                                       27

<PAGE>

warranties if such liability, loss or damage shall be suffered by QIAGEN as a
result of such material untruth, inaccuracy or breach of any facts or
circumstances constituting such material untruth, inaccuracy or breach.

               (b)   Nothing in this Section 3.6 shall limit or in any way
diminish the liability of the Company or the Company Shareholders to QIAGEN with
respect to any breach of any representation or warranty of the Company contained
herein.

                                    ARTICLE 4
           REPRESENTATIONS AND WARRANTIES OF THE COMPANY SHAREHOLDERS

        Each of the Company Shareholders represents and warrants to QIAGEN that
such Company Shareholder is the record and beneficial owner of all of the
outstanding Company Shares set forth opposite his, her or its name on Schedule I
attached hereto, and such Company Shares are owned by such Company Shareholder
free and clear of all Liens, claims, encumbrances, interests of, and rights in,
others.

                                   ARTICLE 5
             REPRESENTATIONS AND WARRANTIES OF QIAGEN AND MERGER SUB

        QIAGEN and Merger Sub hereby, jointly and severally, represent and
warrant to the Company that:

        5.1    Organization and Qualification.

               (a)   Each of QIAGEN and Merger Sub is a corporation duly
organized, validly existing and in good standing under the laws of its
respective jurisdiction of incorporation or organization, and each has the
requisite corporate power and authority, and is in possession of all franchises,
grants, authorizations, licenses, permits, consents, certificates, approvals and
Orders ("QIAGEN Approvals") necessary to own, lease and operate its properties
and to carry on its business as it is now being conducted, except where the
failure to be so qualified, existing and in good standing or to have such power,
authority and QIAGEN Approvals would not, either individually or in the
aggregate, have a Material Adverse Effect.

               (b)   Each of QIAGEN and Merger Sub is duly qualified or licensed
as a foreign corporation to do business, and is in good standing, in each
jurisdiction where the character of the properties owned, leased or operated by
it or the nature of its activities makes such qualification or licensing
necessary, except for such failures to be so duly qualified or licensed and in
good standing that would not, either individually or in the aggregate, have a
Material Adverse Effect.

                                       28

<PAGE>

               (c)   Merger Sub is a newly-formed single purpose entity which
has been formed solely for the purposes of the Merger, has carried on no
business to date and will not carry on any business or engage in any activities
other than those necessary to the Merger.

        5.2    Authorization of Agreement. Each of QIAGEN and Merger Sub has all
requisite corporate power and authority to execute and deliver this Agreement
and each instrument required hereby to be executed and delivered by it at the
Closing, to perform its obligations hereunder and thereunder and to consummate
the transactions contemplated hereby and thereby. The execution and delivery by
each of QIAGEN and Merger Sub of this Agreement and each instrument required
hereby to be executed and delivered by it at the Closing, the performance of
obligations hereunder and thereunder and the consummation of the transactions
contemplated hereby and thereby have been duly and validly authorized by the
Board of Supervisory Directors and the Board of Directors, respectively, of
QIAGEN and Merger Sub, and by QIAGEN as the sole stockholder of Merger Sub, and
except for the filing of the Certificates of Merger, no other corporate
proceedings on the part of QIAGEN or Merger Sub are necessary to authorize this
Agreement or to consummate the transactions contemplated hereby. This Agreement
has been duly executed and delivered by each of QIAGEN and Merger Sub and,
assuming due authorization, execution and delivery hereof by the Company and the
Company Shareholders, constitutes a legal, valid and binding obligation of each
of QIAGEN and Merger Sub, enforceable against each of QIAGEN and Merger Sub in
accordance with its terms, in each case except to the extent that the
enforcement hereof may be limited by (A) bankruptcy, insolvency, reorganization,
moratorium or other similar laws now or hereafter in effect relating to
creditors' rights generally and (B) general principles of equity (regardless of
whether enforceability is considered in a proceeding in equity or at law).

        5.3    Approvals. The execution and delivery by QIAGEN and Merger Sub of
this Agreement or any instrument required by this Agreement to be executed and
delivered by QIAGEN or Merger Sub at the Closing do not, and the performance by
each of QIAGEN and Merger Sub of its respective obligations under this Agreement
or any instrument required by this Agreement to be executed and delivered by
QIAGEN or Merger Sub at the Closing shall not, require QIAGEN or Merger Sub to
obtain any consent, approval, authorization, license, waiver, qualification,
Order or permit of, observe any waiting period imposed by, or require QIAGEN or
Merger Sub to make any filing with or notification to, any Court or Governmental
Authority, except (A) compliance with applicable requirements, if any, of the
Securities Act, the Exchange Act or Blue Sky Laws, (B) the filing of appropriate
Merger or other documents as required by Delaware or Alabama Law, (C) such other
consents, approvals, authorizations, licenses, waivers, qualifications, Orders
or permits, filings or notifications, the failure to obtain or make which would
not have, individually or in the aggregate, a Material Adverse Effect, or (D) as
may arise in any foreign jurisdiction as a consequence of QIAGEN's listing of
the QIAGEN Common Stock on the Neuer Markt division of the Frankfurt Stock
Exchange.

        5.4    No Violation. Assuming effectuation of all filings,
notifications, and registrations with, termination or expiration of any
applicable waiting periods imposed by and receipt of all permits or Orders of
Courts and/or Governmental Authorities set forth in Section 2.4 above, the
execution and delivery by QIAGEN and Merger Sub of this Agreement or any
instrument required by this Agreement to be executed and delivered by QIAGEN or
Merger Sub at the Closing do not, and the performance of this Agreement by each
of QIAGEN or Merger

                                       29

<PAGE>

Sub of its respective obligations under this Agreement or any instrument
required by this Agreement to be executed and delivered by QIAGEN or Merger Sub
at the Closing will not, (i) conflict with or violate the Articles of
Association of QIAGEN, or the Certificate of Incorporation or By-laws of Merger
Sub, (ii) conflict with or violate any Law, Order or Regulation in each case
applicable to QIAGEN or Merger Sub or by which any of their respective
properties is bound or affected, or (iii) result in any breach or violation of
or constitute a default (or an event that with notice or lapse of time or both
would become a default) under any note, bond, mortgage, indenture, contract,
agreement, lease, license, permit, franchise or other instrument or obligation
to which the QIAGEN or Merger Sub is a party or by which QIAGEN or Merger Sub or
any of their respective properties is bound or affected.

                                    ARTICLE 6
                             ADDITIONAL OBLIGATIONS

        6.1    Employee Benefits.

               (a)   QIAGEN agrees that individuals who are employed by the
Company immediately prior to the Effective Time shall become employees of the
Surviving Corporation upon the Effective Time (each such employee, a "Company
Employee"); provided, however, that this Section 6.1 shall not be construed to
limit the ability of the Company or any of its Subsidiaries to terminate the
employment of any Company Employee at any time.

               (b)   QIAGEN will, or will cause the Surviving Corporation to,
give Company Employees full credit for purposes of eligibility (including
service and waiting period requirements), vesting, benefit accrual and
determination of the level of benefits under any employee benefit plans or
arrangements maintained by the QIAGEN or the Surviving Corporation in which the
Company Employees are eligible to participate or to be covered after the
Effective Time, for such Company Employees' service with the Company to the same
extent recognized by the Company immediately prior to the Effective Time.

               (c)   QIAGEN will, or will cause the Surviving Corporation to,
(i) waive all limitations as to preexisting conditions, exclusions and waiting
periods and service requirements with respect to participation and coverage
requirements applicable to the Company Employees under any welfare benefit plans
of QIAGEN or the Surviving Corporation in which Company Employees are eligible
to participate or to be covered after the Effective Time, other than
limitations, waiting periods or service requirements that are already in effect
with respect to such Company Employees and that have not been satisfied under
any welfare plan previously maintained for the Company Employees, and (ii)
provide each Company Employee with credit for any co-payments and deductibles
paid in the year in which the Effective Time occurs under the welfare benefit
plans of the Company or the Surviving Corporation (as shown on the Company's or
the Surviving Corporation's records) in satisfying any applicable deductible or
out-of-pocket requirements under any welfare benefit plans of QIAGEN in which
Company Employees are eligible to participate or to be covered in the year in
which the Effective Time occurs.

               (d)   It is QIAGEN's present intention that the operations of the
Company shall be relocated to QIAGEN's U.S. headquarters in Germantown,
Maryland.

                                       30

<PAGE>

    6.2      Listings. QIAGEN shall use commercially reasonable efforts to cause
the QIAGEN Common Stock to be issued in the Merger to be approved for listing on
(i) the Nasdaq National Market not later than the effectiveness of the Resale
Registration Statement (as defined in Section 1.6(c) hereof) and (ii) the Neuer
Markt division of the Frankfurt Stock Exchange as soon as practicable after the
Effective Time.

    6.3      Registration of Shares Issued in the Merger.

             (a)   Registrable Shares. For purposes of this Agreement,
"Registrable Shares" shall mean the Merger Shares issued to the Company
Shareholders in accordance with Section 1.6 of this Agreement, but shall exclude
any Escrow Shares or Performance Shares.

             (b)   Required Registration. Within thirty (30) days after the
Effective Time, QIAGEN shall prepare and file with the SEC a Resale Registration
Statement under the Securities Act with respect to the sale of the Registrable
Shares by the Company Shareholders or their permitted distributees. QIAGEN shall
use its commercially reasonable efforts to cause the Resale Registration
Statement and all registrations, qualifications and compliances (including,
without limitation, obtaining appropriate qualifications under applicable state
securities or "blue sky" laws and compliance with any other applicable
governmental requirements or regulations) as the Company Shareholders may
reasonably request and that would permit or facilitate the sale of Registrable
Shares to become effective within ninety (90) days after the Effective Time;
provided, however, that QIAGEN shall not be required in connection therewith to
qualify to do business or to file a general consent to service of process in any
such state or jurisdiction. QIAGEN will provide the Company Shareholders upon
request with as many copies of the prospectus contained in the Resale
Registration Statement as the Company Shareholders may reasonably request.

             (c)   Effectiveness; Suspension Right.

                   (i)   From and after the effectiveness of the Resale
    Registration Statement as contemplated by Section 6.3(b), QIAGEN will use
    its best efforts to maintain such effectiveness and other applicable
    registrations, qualifications and compliances until the earlier of (A) such
    time as the Company Shareholders may sell all of the Registrable Shares
    held by them without registration pursuant to Rule 144 under the Securities
    Act within a three-month period or pursuant to Regulation S under the
    Securities Act or (B) such time as all of the Registrable Shares have been
    sold by the Company Shareholders (the "Registration Effective Period"), and
    from time to time QIAGEN will amend or supplement the Resale Registration
    Statement and the prospectus contained therein as and to the extent
    necessary to comply with the Securities Act, the Exchange Act and any
    applicable state securities statute or regulation, subject to the following
    limitations and qualifications.

                   (ii)  Following the Registration Statement Effective Date,
    the Company Shareholders will be permitted, subject to the Suspension Right
    (as defined in paragraph (iii) below), to offer and sell Registrable Shares
    during the Registration Effective Period in the manner described in the
    Resale Registration Statement provided that the Resale

                                       31

<PAGE>

    Registration Statement remains effective and no stop order or suspension of
    the use of the Resale Registration Statement has been imposed by the SEC.

                (iii)    Subject to the provisions of this Section 6.3, QIAGEN
    shall have the right at any time to require that the Company Shareholders
    suspend further open market offers and sales of Registrable Shares
    whenever, and for so long as, in the reasonable judgment of QIAGEN after
    consultation with counsel there is in existence material undisclosed
    information or events with respect to QIAGEN (the "Suspension Right"). In
    the event QIAGEN exercises the Suspension Right, such suspension will
    continue for a period of time reasonably necessary for disclosure to occur
    at a time that is not detrimental to QIAGEN and its stockholders or until
    such time as the information or event is no longer material, each as
    determined in good faith by QIAGEN after consultation with counsel. QIAGEN
    will promptly give the Company Shareholders notice of any such suspension
    and will use commercially reasonable efforts to limit the length of the
    suspension to ten (10) days. Notwithstanding any other provision of this
    Section 6.3, such suspension shall not exceed twenty (20) Business Days. In
    addition, during any period when a suspension is in effect hereunder,
    QIAGEN will suspend the use of, and not file, any other registration
    statements.

       (d)      Expenses. QIAGEN shall bear all costs and expenses of
registration under this Section 6.3, including, without limitation, printing
expenses, legal fees and disbursements of counsel for QIAGEN, legal fees and
disbursements (not to exceed $10,000 in aggregate) of one counsel for the
Company Shareholders, "blue sky" expenses, accounting fees and filing fees, but
excluding underwriting commissions or similar charges in connection with the
resale of the QIAGEN Common.

       (e)      Indemnification.

                (i)      To the fullest extent permitted by law, QIAGEN will
indemnify and hold harmless the Company Shareholders, each underwriter of QIAGEN
Common Stock being sold by such Company Shareholders pursuant to this Section
6.3 and each person, if any, who controls the Company Shareholders or
underwriter within the meaning of the Securities Act or the Exchange Act (for
purposes of this Section 6.3(e) only, a "Company Indemnified Person") against
all actions, claims, losses, damages, liabilities and expenses to which they or
any of them become subject under the Securities Act, the Exchange Act or under
any other Law and, except as hereinafter provided, will promptly reimburse as
incurred the Company Indemnified Persons for any legal or other expenses
reasonably incurred by them or any of them in connection with investigating or
defending any actions, whether or not resulting in any liability, insofar as
such losses, claims, damages, expenses, liabilities or actions arise out of or
are based upon any untrue statement or alleged untrue statement of a material
fact in any registration statement and any prospectus filed pursuant to Section
6.3 or any post-effective amendment thereto, or arise out of or are based upon
any omission or alleged omission to state a material fact required to be stated
therein or necessary to make the statements therein, in light of the
circumstances under which they were made, not misleading, or any violation by
QIAGEN of any rule or regulation promulgated under the Securities Act or the
Exchange Act applicable to QIAGEN and relating to action or inaction required of
QIAGEN in

                                       32

<PAGE>

     connection with such registration; provided, however, that QIAGEN shall not
     be liable to any such Company Indemnified Person in respect of any claims,
     losses, damages, liabilities and expenses resulting from any untrue
     statement or alleged untrue statement, or omission or alleged omission made
     in reliance upon and in conformity with information furnished to QIAGEN by
     the Company Indemnified Person specifically for use in connection with such
     registration statement and prospectus or post-effective amendment.

                (ii)   To the fullest extent permitted by law, the Company
     Shareholders will, severally and not jointly, indemnify QIAGEN, each
     person, if any, who controls QIAGEN within the meaning of the Securities
     Act or the Exchange Act, each director of QIAGEN and each officer of QIAGEN
     who signs the Resale Registration Statement and each underwriter of QIAGEN
     Common Stock (for purposes of this Section 6.3 only, a "QIAGEN Indemnified
     Person") against any actions, claims, losses, damages, liabilities and
     expenses to which they or any of them may become subject under the
     Securities Act, the Exchange Act or under any other Law, and, except as
     hereinafter provided, will promptly reimburse such QIAGEN Indemnified
     Person for any legal or other expenses reasonably incurred by them or any
     of them in connection with investigating or defending any actions, whether
     or not resulting in any liability, insofar as such losses, claims, damages,
     expenses, liabilities or actions arise out of or are based upon any untrue
     statement or alleged untrue statement of a material fact in any
     registration statement and any prospectus filed pursuant to Section 6.3 or
     any post-effective amendment thereto, or any omission or alleged omission
     to state a material fact required to be stated therein or necessary to make
     the statements therein, in light of the circumstances under which they were
     made, not misleading, which untrue statement or alleged untrue statement or
     omission or alleged omission was made in reliance upon and in conformity
     with information furnished QIAGEN by the Company Shareholders specifically
     for use in connection with such registration statement, prospectus or
     post-effective amendment.

                (iii)  Each Company Indemnified Person or QIAGEN Indemnified
     Person entitled to indemnification under this Section 6.3 (an "Indemnified
     Person") shall give notice to the party required to provide indemnification
     (the "Indemnifying Person") promptly after such Indemnified Person has
     actual knowledge of any claim as to which indemnity may be sought and shall
     permit the Indemnifying Person to assume the defense of any such claim and
     any litigation resulting therefrom, provided that counsel for the
     Indemnifying Person who conducts the defense of such claim or any
     litigation resulting therefrom shall be approved by the Indemnified Person
     (whose approval shall not unreasonably be withheld), and the Indemnified
     Person may participate in such defense at such party's expense, and
     provided further that the failure of any Indemnified Person to give notice
     as provided herein shall not relieve the Indemnifying Person of its
     obligations under this Section 6.3 except to the extent the Indemnifying
     Person is materially prejudiced thereby. No Indemnifying Person, in the
     defense of any such claim or litigation, shall (except with the consent of
     each Indemnified Person) consent to entry of any judgment or enter into any
     settlement that does not include as an unconditional term thereof the
     giving by the claimant or plaintiff to each Indemnified Person of a
     complete release from all liability in respect to such claim or litigation.
     Each Indemnified Person shall furnish such information regarding itself or
     the claim in question as an

                                       33

<PAGE>

     Indemnifying Person may reasonably request in writing and as shall be
     reasonably required in connection with the defense of such claim and
     litigation resulting therefrom.

To the extent that the indemnification provided for in this Section 6.3 is held
by a court of competent jurisdiction to be unavailable to an Indemnified Person
with respect to any loss, liability, claim, damage or expense referred to
herein, then the Indemnifying Person, in lieu of indemnifying such Indemnified
Person hereunder, shall contribute to the amount paid or payable by such
Indemnified Person as a result of such loss, liability, claim, damage or expense
in such proportion as is appropriate to reflect the relative fault of the
Indemnifying Person on the one hand and of the Indemnified Person on the other
in connection with the statements or omissions which resulted in such loss,
liability, claim, damage or expense, as well as any other relevant equitable
considerations. The relative fault of the Indemnifying Person and of the
Indemnified Person shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or the
omission or alleged omission to state a material fact relates to information
supplied by the Indemnifying Person or by the Indemnified Person and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such statement or omission.

           (f)  "Market Stand-Off" Agreement. Each Company Shareholder agrees,
if requested by QIAGEN and an underwriter of any securities of the Company, (i)
not to lend, offer, pledge, sell, contract to sell, sell any option or contract
to purchase, purchase any option or contract to sell, grant any option, right or
warrant to purchase, or otherwise transfer or dispose of, directly or
indirectly, any shares of QIAGEN Common Stock or any securities convertible into
or exercisable or exchangeable for QIAGEN Common Stock (whether such shares or
any such securities are then owned by such holder or are thereafter acquired),
or (ii) enter into any swap or other arrangement that transfers to another, in
whole or in part, any of the economic consequences of ownership of the QIAGEN
Common Stock, whether any such transaction described in clause (i) or (ii) above
is to be settled by delivery of QIAGEN Common Stock or such other securities, in
cash or otherwise, whether in privately negotiated or open market transactions,
any QIAGEN Common Stock or other securities of QIAGEN held by it during the one
hundred eighty (180) day period following the effective date of a registration
statement. Such agreement shall be in writing in form and substance satisfactory
to QIAGEN and such underwriter. QAGEN may impose stop-transfer instructions with
respect to the shares subject to the foregoing restrictions until the end of the
"market stand-off" period.

     6.4   Agreement Not to Compete.

           (a) Each of Patrick Weiss, Violette Weiss and Stefan Pitsch agrees
that for a period of three (3) years after the Closing Date, that he, she or it
will not, directly or indirectly, own, manage, control or participate in the
ownership, management or control of, or be employed or engaged by or otherwise
affiliated or associated as a consultant, independent contractor or otherwise
with, any other corporation, partnership, proprietorship, firm, association or
other business entity, or otherwise engage in any business, that is engaged in
any manner in or otherwise competes with the services and business of the
Company or QIAGEN and its subsidiaries in any state in the United States or any
foreign country in which the Company or QIAGEN or any of its subsidiaries is
then doing business; provided, however, that (i) the ownership of not more than
1% of the stock of any publicly traded corporation shall not be

                                       34

<PAGE>

deemed a violation of this covenant, (ii) holding a position in a college,
university or other academic institution in which research is conducted by other
persons in other laboratories that may be competitive with the business of the
Company or QIAGEN shall not be deemed a violation of this covenant so long as
such academic position is not directly or indirectly related to sponsored
research that would otherwise violate this subsection (a), and (iii), the
activities described on Section 6.4 of the Company Disclosure Schedule shall not
be deemed a violation of this covenant.

             A business will be deemed to "compete with the services and
business" of the Company or QIAGEN and its subsidiaries if its businesses is (i)
the selling marketing, brokering, manufacturing or distributing of products or
the provision of services related to the handling, preparation, purification,
modification or detection of nucleic acids, or the preparation and supply of
synthetic nucleic acids or (ii) any activities that are intended to reduce or
could result in the reduction of the need for the products and services
described in the foregoing clause (i).

             (b) Each party hereto expressly agrees and understands that the
remedy at law for any breach by it of this Agreement will be inadequate and that
the damages flowing from such breach are not readily susceptible to being
measured in monetary terms. Accordingly, it is acknowledged that QIAGEN shall be
entitled, among other remedies, to immediate injunctive relief for any such
breach and to obtain a temporary order restraining any threatened or further
breach. Any covenant contained hereinabove shall nevertheless, if breached, give
rise to monetary damages in accordance with the other provisions of this
Agreement.

             (c) In the event a party shall violate any legally enforceable
provision of this Section 6.4 as to which there is a specific time period during
which such party is prohibited from taking certain actions or from engaging in
certain activities, as set forth in this Section 6.4, then, in such event, such
violation shall toll the running of such time period from the date of such
violation until such violation shall cease.

    6.5      Conduct of Business Pending Closing. The Company covenants and
agrees that, between the date hereof and the Effective Time, except as expressly
required or permitted by this Agreement or unless QIAGEN shall otherwise agree
in writing, the Company shall conduct and shall cause the businesses of each of
its Subsidiaries to be conducted only in, and the Company and its Subsidiaries
shall not take any action except in, the ordinary course of business, consistent
with past practices. The Company shall use its best efforts to preserve intact
the business organization and assets of the Company and each of its
Subsidiaries, and to operate, and cause each of its Subsidiaries to operate,
according to plans and budgets provided to QIAGEN, to keep available the
services of the present officers, employees and consultants of the Company and
each of its Subsidiaries, to maintain in effect Material Agreements and to
preserve the present relationships of the Company and each of its Subsidiaries
with advertisers, sponsors, customers, licensees, suppliers and other Persons
with which the Company or any of its Subsidiaries has business relations. The
Company shall immediately notify QIAGEN of any breach of the covenant contained
in this Section 6.5.

    6.6      ETH Agreement. The Company covenants and agrees that the Company
shall immediately provide to QIAGEN a copy of any notices or other
communications given to ETH Transfer on behalf of, or received from ETH Transfer
by, Patrick Weiss, Stephan Pitsch, Luzi

                                       35

<PAGE>

Jenny or any entity formed or controlled by any of them (individually or in
the aggregate) under the ETH Agreement (as defined in the Option Agreement) at
the same time as such notices are given or received.

     6.7  SouthTrust Bank. As soon as practicable following the Closing, QIAGEN
shall cause SouthTrust Bank to release Patrick Weiss, Violette Weiss and Stephan
Pitsch from their personal guarantees of the indebtedness evidenced by that
certain $400,000 Promissory Note of the Company originally issued to SouthTrust
Bank and dated November 22, 2001 (the "SouthTrust Note").

     6.8  Acknowledgement of ETH Transfer. The Founders shall use their efforts
to deliver within two weeks following the closing, and in any event shall
deliver on or prior to May 30, 2002, written evidence, in form and substance
satisfactory to QIAGEN in its sole discretion, that ETH Transfer: (i)
acknowledges that there are no defaults or breaches under the ETH Agreement (as
defined in the Option Agreement) and consents to the structure pursuant to which
the inventions which are the subject matter of the ETH Agreement have been, and
are proposed to be, commercialized and (ii) agrees to send a copy to QIAGEN of
any notices or other communications given or received by ETH Transfer under the
ETH Agreement at the same time as such notices are given or received by ETH
Transfer.

     6.9  XAG Change of Name. As soon as practicable following the Closing, and
in any event within two weeks after the Closing, the Founders shall provide
evidence to QIAGEN that XAG has changed its name to a name reasonably
satisfactory to QIAGEN which shall not contain the word "XERAGON" or any
derivation thereof.

                                    ARTICLE 7
                              CONDITIONS OF MERGER

     7.1  Conditions to Obligation of Each Party to Effect the Merger. The
respective obligations of each party to effect the Merger shall be subject to
the satisfaction at or prior to the Effective Time of the following conditions,
any or all of which may be waived by the party entitled to the benefit thereof,
in whole or in part, the extent permitted by applicable Law:

          (a)  Shareholder Approval. This Agreement and the Merger shall have
been authorized by the requisite vote of the shareholders of the Company in
accordance with the provisions of the ABCA and the Articles of Incorporation or
equivalent organizational documents and by-laws of the Company.

          (b)  Regulatory Approvals. All approvals and consents of applicable
Courts and/or Governmental Authorities required to consummate the Merger shall
have been received, except for such approvals and consents, the failure of which
to have been so received, shall not have a Material Adverse Effect, shall have
expired or been terminated.

          (c)  No Injunctions or Restraints; Illegality. No temporary
restraining order, preliminary or permanent injunction or other Order (whether
temporary, preliminary or permanent) issued by any Court of competent
jurisdiction or other legal restraint or prohibition (an "Injunction")
preventing the consummation of the Merger shall be in effect which is
non-appealable, nor shall any proceeding brought by any administrative agency or
commission or

                                       36

<PAGE>

other Governmental Authority, domestic or foreign, seeking any of the foregoing
be pending, and there shall not be any action taken, or any statute, rule,
regulation or order enacted, entered, enforced or deemed applicable to the
Merger, which makes the consummation of the Merger illegal.

          (d)  No Order. No Court or Governmental Authority having jurisdiction
over the Company or QIAGEN shall have enacted, issued, promulgated, enforced or
entered any Law, Regulation or Order (whether temporary, preliminary or
permanent) which is then in effect and which has the effect of making the Merger
illegal or otherwise prohibiting consummation of the Merger substantially on the
terms contemplated by this Agreement without an opportunity for appeal by either
party.

     7.2  Additional Conditions to Obligations of QIAGEN and Merger Sub. The
obligations of QIAGEN and Merger Sub to effect the Merger are also subject to
the following conditions, any or all of which may be waived by QIAGEN and Merger
Sub, in whole or in part, to the extent permitted by applicable Law:

          (a)  Representations and Warranties. The representations and
warranties of the Company contained in this Agreement and the Related Agreements
shall be true and correct in all material respects on and as of the Effective
Time, with the same force and effect as if made on and as of the Effective Time,
except for (i) changes contemplated by this Agreement (including the Company
Disclosure Schedule), (ii) representations and warranties that are qualified by
materiality or Material Adverse Effect, in which case such representations and
warranties shall be true and correct in all respects, and (iii) representations
and warranties which address matters only as of a particular date, in which case
such representations and warranties qualified as to materiality or Material
Adverse Effect shall be true and correct in all respects, and those not so
qualified shall be true and correct in all material respects, on and as of such
particular date; and QIAGEN shall have received a certificate to such effect
signed by the President of the Company.

          (b)  Agreements and Covenants. The Company shall have performed or
complied in all material respects with all agreements and covenants required by
this Agreement and the Related Agreements to be performed or complied with by it
on or prior to the Effective Time. QIAGEN shall have received a certificate to
such effect signed by the President of the Company.

          (c)  Third Party Consents. QIAGEN shall have received evidence, in
form and substance reasonably satisfactory to it, that those licenses, Permits,
consents, waivers, approvals, authorizations, qualifications or Orders
(including all United States and foreign governmental and regulatory rulings and
approvals) of Governmental Authorities and other third parties described in
Section 2.5(a) or (b) of the Company Disclosure Schedule (or not described in
Section 2.5(a) or (b) of the Company Disclosure Schedule but required as
described in Section 2.5(a) or (b) of this Agreement) have been obtained.

          (d)  No Material Adverse Effect. There shall not have occurred any
event and no circumstance shall exist which, alone or together with any one or
more other events or

                                       37

<PAGE>

circumstances has had, is having or would reasonably be expected to have a
Material Adverse Effect on the Company.

          (e)  Certificates of Merger.  The Company shall have executed and
delivered the Certificates of Merger.

          (f)  Opinion of Counsel to the Company.  QIAGEN shall have received
the opinion of Lanier Ford Shaver & Payne P.C., dated as of the Effective Time,
substantially in the form of Exhibit E.

          (g)  New XAG License Agreement. The Old XAG License Agreement shall
have been terminated and QIAGEN or one of its Affiliates and XAG shall have
entered into a license agreement with respect to XAG's Intellectual Property
Rights, substantially in the form of Exhibit F (the "New XAG License
Agreement").

          (h)  Releases. QIAGEN shall have received Release Agreements
substantially in the form of Exhibit G executed and delivered by each Company
Shareholder (the "Release Agreements").

          (i)  Dissenting Shares.  The Dissenting Shares shall comprise less
than 5% of the issued and outstanding Company Shares.

          (j)  Shareholder Agreements.  Each of the Company Shareholders shall
have executed and delivered to QIAGEN a Shareholder Agreement in substantially
the form attached hereto as Exhibit H (the "Shareholder Agreement").

          (k)  Acceptance of Employment. Patrick Weiss and Violette Weiss shall
have agreed to become employees of QIAGEN or one of its Affiliates.

          (l)  Escrow Agreement. QIAGEN and the Shareholders' Committee (as
defined  therein) shall have entered into the Escrow  Agreement with the Escrow
Agent.

          (m)  Restriction Agreement. QIAGEN, Patrick Weiss, Luzi Jenny (by
virtue of a power of attorney granted to Patrick Weiss), Stefan Pitsch, Berina
AG and Edgar Rutishauser shall have entered into a Restriction Agreement in
substantially the form attached hereto as Exhibit I (the "Restriction
Agreement").

          (n)  Option Agreement. QIAGEN, Patrick Weiss, Luzi Jenny (by virtue of
a power of attorney granted to Patrick Weiss), Stefan Pitsch and XAG shall have
entered into an Option Agreement in substantially the form attached hereto as
Exhibit J (the "Option Agreement").

          (o)  Declaration.  Luzi Jenny shall have delivered a Declaration in
substantially the form attached hereto as Exhibit L (the "Declaration").

          (p)  Subscription Agreement.  Each of the Company Stockholders shall
have entered into a Subscription Agreement in substantially the form attached
hereto as Exhibit M (the "Subscription Agreement").

                                       38

<PAGE>

          (q)  XAG. QIAGEN shall have received evidence satisfactory to it that
XAG has terminated all of its distribution agreements (other than the agreements
with Glen Research Corporation).

          (r)  No Indebtedness.  QIAGEN shall have received evidence
satisfactory to it that the Company has no indebtedness outstanding as of the
Closing Date other than a maximum of $330,000 evidenced by the SouthTrust Note.

          (s)  Amendment of Lease.  QIAGEN shall have received evidence
satisfactory to it that the Lease Agreement between the Company and James R.
Hudson, Jr. and Suanne Hudson has been amended to its satisfaction.

          (t)  QIAGEN Satisfaction with Intellectual Property Issues. QIAGEN
shall be satisfied in all respects, in its sole discretion, with the
Intellectual Property Rights including without limitation being satisfied: (i)
with its due diligence investigation of the Intellectual Property Rights, (ii)
that the Intellectual Property Rights, including without limitation rights
granted under the New XAG License Agreement, are sufficient to conduct its
business in the manner QIAGEN intends to do so and (iii) that this Agreement and
the Related Agreements sufficiently protect QIAGEN's interest in the
Intellectual Property Rights, including without limitation rights granted under
the New XAG License Agreement, from and after the Effective Time.

     7.3  Additional Conditions to Obligations of the Company. The obligation of
the Company to effect the Merger is also subject to the following conditions,
any or all of which may be waived by Company, in whole or in part, to the extent
permitted by applicable Law:

          (a)  Representations and Warranties. The representations and
warranties of QIAGEN and Merger Sub contained in this Agreement and the Related
Agreements shall be true and correct in all material respects on and as of the
Effective Time, with the same force and effect as if made on and as of the
Effective Time, except for (i) changes contemplated by this Agreement, (ii)
representations and warranties that are qualified by materiality or Material
Adverse Effect, in which case such representations and warranties shall be true
and correct in all respects, and (iii) representations and warranties which
address matters only as of a particular date, in which case such representations
and warranties qualified as to materiality or Material Adverse Effect shall be
true and correct in all respects, and those not so qualified shall be true and
correct in all material respects, on and as of such particular date; and the
Company shall have received a certificate to such effect signed by the Chief
Financial Officer of QIAGEN.

          (b)  Agreements and Covenants. QIAGEN and Merger Sub shall have
performed or complied in all material respects with all agreements and covenants
required by this Agreement to be performed or complied with by them on or prior
to the Effective Time, and the Company shall have received a certificate to such
effect signed by the Chief Financial Officer of QIAGEN.

          (c)  Certificates of Merger.  Merger Sub shall have executed and
delivered the Certificates of Merger.

                                       39

<PAGE>

          (d)  Opinion of Counsel to QIAGEN. The Company shall have received the
opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. dated as of the
Effective Time, substantially in the form of Exhibit K.

          (e)  No Material Adverse Effect. From and including the date hereof,
there shall not have occurred any event and no circumstance shall exist which,
alone or together with any one or more other events or circumstances has had, is
having or would reasonably be expected to have a Material Adverse Effect on
QIAGEN; provided, however, that no change in the market price of QIAGEN Common
Stock shall constitute a Material Adverse Effect.

                                    ARTICLE 8
                             INDEMNIFICATION; ESCROW

     8.1  Survival. Subject to Section 8.5 hereof, all representations and
warranties of the parties in this Agreement, in the Related Agreements or in any
other agreement, instrument or document furnished in connection with this
Agreement or the transactions contemplated hereby, shall survive the Closing and
shall expire on the date which is eighteen months after the Closing (the
"Expiration Date").

     8.2  Indemnification. Each of the Company Shareholders (including the
Founders) shall severally indemnify, defend and hold harmless QIAGEN and the
Surviving Corporation and their respective officers, directors, employees and
stockholders (other than the Company Shareholders and their successors in
interest) and their successors and assigns from, against and with respect to any
claim, liability, obligation, loss, damage, assessment, judgment, cost and
expense (including, without limitation, reasonable attorneys' and accountants'
fees and costs and expenses reasonably incurred in investigating, preparing,
defending against or prosecuting any litigation or claim, action, suit,
proceeding or demand) of any kind or character ("Damages") arising out of or in
any manner incident, relating or attributable to:

               (i)    any material inaccuracy in any representation or material
     breach of warranty by the Company or an indemnifying party contained in
     this Agreement (other than the representations and warranties given in
     Sections 2.1, 2.2, 2.3, 2.4, 2.8, 2.14, 2.20, 2.21 and 2.22 of this
     Agreement);

               (ii)   any material inaccuracy in any representation, or material
     breach of warranty by the Company or an indemnifying party, contained in
     Sections 2.1, 2.2, 2.3, 2.4, 2.8, 2.14, 2.20, 2.21 and 2.22 of this
     Agreement, any Related Agreement or in any certificate, instrument of
     transfer or other document or agreement executed in connection with this
     Agreement or otherwise made or given in connection with this Agreement;

               (iii)  any failure by the Company, XAG or an indemnifying party
     to perform or observe, or to have performed or observed, in full, any
     covenant, agreement or condition to be performed or observed by it under
     this Agreement, any Related Agreement or under any certificates or other
     documents or agreements executed in connection with this Agreement;

                                       40

<PAGE>

               (iv)    reliance by QIAGEN on any books or records of the
     Company or reliance by QIAGEN on any information furnished to QIAGEN
     pursuant to this Agreement by or on behalf of the Company or the Company
     Shareholders;

               (v)     any claim arising out of or relating to the operation of
     the business of the Company on or prior to the Closing Date or facts and
     circumstances existing at or prior to the Closing Date, whether or not such
     liabilities or obligations were known on such date;

               (vi)    any breach by XAG of the New XAG License Agreement; and

               (vi)    any claims by any shareholder, licensor, licensee or
     customer of XAG against QIAGEN, the Company or the Surviving Corporation.

     8.3  Claims for Indemnification. In the event of the occurrence of any
event which any party asserts is an indemnifiable event pursuant to this Article
7, the party claiming indemnification (the "Indemnified Party") shall provide
prompt notice to the party required to provide indemnification (the
"Indemnifying Party"), specifying in detail the facts and circumstances with
respect to such claim and the basis for which indemnification is available
hereunder. If such event involves the claim of any third party, the Indemnifying
Party shall have the right to control the defense or settlement of such claim;
provided, however, that (i) the Indemnified Party shall be entitled to
participate in the defense of such claim at its own expense, (ii) the
Indemnifying Party shall obtain the prior written approval of the Indemnified
Party (which approval shall not be unreasonably withheld or delayed) before
entering into any settlement of such claim which does not include as an
unconditional term thereof the giving by the claimant or plaintiff to the
Indemnified Party of a complete release from all liability in respect to such
claim or litigation, (iii) the Indemnifying Party shall not be entitled to
control (but shall be entitled to participate at its own expense in the defense
of), and the Indemnified Party shall be entitled to have sole control over, and
shall assume all expense with respect to, the defense or settlement of any claim
to the extent such claim seeks an order, injunction or other equitable relief
against the Indemnified Party which, if successful, could materially interfere
with the business, operations, assets, condition (financial or otherwise) or
prospects of the Indemnified Party; provided, that, the Indemnified Party shall
provide written notice to the Indemnifying Party of its election to assume
control over the defense of such claim pursuant to this clause (iii), and (iv)
if the Indemnifying Party is entitled to but fails to assume control over the
defense of a claim as provided in this Section 8.3, providing that Damages
associated with such claim are covered by the indemnity provisions of Section
8.2, the Indemnified Party shall have the right to defend such claim, provided
further that the Indemnified Party shall obtain the prior written approval of
the Indemnifying Party (which approval shall not be unreasonably withheld or
delayed) before entering into any settlement of such claim if, pursuant to or as
a result of such settlement, injunctive or other non-monetary relief would
imposed against the Indemnifying Party.

     In the event that the Indemnifying Party shall be obligated to indemnify
the Indemnified Party pursuant to this Article 7, the Indemnifying Party shall,
upon payment of such indemnity in full, be subrogated to all rights of the
Indemnified Party with respect to the claim to which such indemnification
relates.

                                       41

<PAGE>

     8.4  Deductible with Respect to Indemnification. Subject to Section 8.5
hereof, no claim by QIAGEN (on behalf of itself and the Surviving Corporation,
as the case may be) shall be made against the Company Shareholders for
indemnification pursuant to this Article 8 with respect to any item of Damages
arising out of, relating to or attributable to this Agreement or the
transactions contemplated hereby, unless such item, together with the aggregate
of all prior Damages of QIAGEN and its Affiliates for which indemnification
could be sought pursuant to this Article 8, shall exceed $20,000 (the
"Deductible Amount"), in which event QIAGEN shall be entitled, subject to the
provisions of this Article 8, to make claims for indemnification hereunder to
the extent of any and all of such Damages in excess of the Deductible Amount.

     8.5  Limitations of Indemnification. Notwithstanding anything in this
Article 8 to the contrary, any Damages to QIAGEN or its Affiliates resulting
from fraud or intentional misrepresentation by any executive officer or director
of the Company or more than 10% beneficial owner of outstanding Company Shares
with respect to a representation or warranty contained herein at the time such
representation or warranty was made or at the time of the Closing (i) shall not
be subject to the Deductible Amount or the Expiration Date and (ii) QIAGEN's
recovery shall not be limited to the Escrow Fund.

     8.6  Escrow Arrangements.

          (a)  On the Effective Time, the Company Shareholders will be deemed to
have received and deposited with the Escrow Agent (as defined below) the Escrow
Shares plus any additional shares as may be issued with respect to the Escrow
Shares upon any stock split (including a stock split effected through a dividend
of stock) or recapitalization effected by QIAGEN after the Effective Time,
without any act of any Company Shareholders. Within twenty-five (25) Business
Days after the Effective Time, the Escrow Shares, without any act of any Company
Shareholders, will be deposited with State Street Bank (or another institution
acceptable to QIAGEN and the Company Shareholders) as Escrow Agent (the "Escrow
Agent"), such deposit to constitute an escrow fund (the "Escrow Fund") to be
governed by the terms of the Escrow Agreement. The Escrow Fund shall be
available to fund the indemnification of QIAGEN and the Surviving Corporation
with respect to Damages incurred by QIAGEN and the Surviving Corporation after
the Effective Time. Subject to Section 8.5 hereof, the indemnification
obligations of the Company Shareholders pursuant to clause (i) of Section 8.2
hereof shall be limited to amounts deposited in the Escrow Fund.

          (b)  Subject to the terms of the Escrow Agreement, the Escrow Fund
shall be in existence immediately following the Effective Time and shall
terminate on the Expiration Date.

                                    ARTICLE 9
                        TERMINATION, AMENDMENT AND WAIVER

     9.1  Termination. This Agreement may be terminated and the Merger
contemplated hereby may be abandoned at any time prior to the Effective Time,
notwithstanding approval thereof by the stockholders of the Company:

                                       42

<PAGE>

          (a)  By mutual written consent duly authorized by the Boards of
Directors of QIAGEN and the Company; or

          (b)  By either QIAGEN or the Company if the Merger shall not have been
consummated on or before May 30, 2002; provided, however, that the right to
terminate this Agreement under this Section 9.1(b) shall not be available to any
party whose willful failure to fulfill any material obligation under this
Agreement has been the cause of, or resulted in, the failure of the Merger to
have been consummated on or before such date; or

          (c)  By either QIAGEN or the Company, if a Court or Governmental
Authority shall have issued an Order or taken any other action, in each case,
which has become final and non-appealable and which restrains, enjoins or
otherwise prohibits the Merger.

     9.2  Effect of Termination. Except as provided in this Section 9.2, in the
event of the termination of this Agreement pursuant to Section 9.1, this
Agreement (other than this Section 9.2 and Sections 9.3 and Article 10, which
shall survive such termination) will forthwith become void, and there will be no
liability on the part of QIAGEN, Merger Sub or the Company or any of their
respective officers or directors to the other and all rights and obligations of
any party hereto will cease, except that nothing herein will relieve any party
from liability for any breach, prior to termination of this Agreement in
accordance with its terms, of any representation, warranty, covenant or
agreement contained in this Agreement.

     9.3  Amendment. This Agreement may be amended by the parties hereto by
action taken by or on behalf of their respective Boards of Directors at any time
prior to the Effective Time; provided, however, that, after approval of the
Merger by the stockholders of the Company, no amendment may be made which would
reduce the amount or change the type of consideration into which each Company
Share shall be converted upon consummation of the Merger. This Agreement may not
be amended except by an instrument in writing signed by QIAGEN, Merger Sub and
the Company.

     9.4  Waiver. At any time prior to the Effective Time, any party hereto may
extend the time for the performance of any of the obligations or other acts
required hereunder, waive any inaccuracies in the representations and warranties
contained herein or in any document delivered pursuant hereto and waive
compliance with any of the agreements or conditions contained herein. Any such
extension or waiver shall be valid if set forth in an instrument in writing
signed by the party or parties to be bound thereby.

                                   ARTICLE 10
                               GENERAL PROVISIONS

     10.1 Notices. All notices or other communications which are required or
permitted hereunder shall be in writing and sufficient if delivered personally
or sent by nationally recognized overnight courier or by registered or certified
mail, postage prepaid, return receipt requested, or by electronic mail, with a
confirmatory copy thereof to be delivered by mail (as aforesaid) within 24 hours
of such electronic mail, or by telecopier, with confirmation as provided above,
addressed as follows:

                                       43

<PAGE>

               (a)  If to QIAGEN or Merger Sub:

                    QIAGEN N.V.
                    Sportstraat 50
                    KJ 5911 Venlo
                    The Netherlands
                    Telephone:  011 31 77 320-8400
                    Telecopier:  011 31 77 320-8409
                    Attention: Dr. Metin Colpan, Chief Executive Officer

With a copy to:
                    Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                    One Financial Center
                    Boston, Massachusetts  02111
                    Telephone: (617) 542-6000
                    Telecopier: (617) 542-2241
                    Attention:  Jonathan L. Kravetz, Esq.

               (b)  If to the Company:

                    Xeragon, Inc.
                    2307 Spring Branch Road
                    Huntsville, AL 35801
                    Telephone: (256) 704 3063
                    Telecopier: (256) 704 3066
                    Attention:  President

With a copy to:

                    Lanier Ford Shaver & Payne P.C.
                    200 West Side Square, Suite 5000
                    Huntsville, AL 35801
                    Telephone: (256) 535-1100
                    Telecopier: (256) 533-9322
                    Attention: Richard J. Marsden, Esq.

or to such other address as the party to whom notice is to be given may have
furnished to the other party in writing in accordance herewith. All such notices
or communications shall be deemed to be received (a) in the case of personal
delivery, on the date of such delivery, (b) in the case of nationally recognized
overnight courier, on the next Business Day after the date when delivered to the
courier (c) in the case of facsimile transmission or electronic mail, upon
confirmed receipt, and (d) in the case of mailing, on the fifth (5th) Business
Day following the date on which the piece of mail containing such communication
was posted.

     10.2 Disclosure Schedules. The Company Disclosure Schedule shall be divided
into sections corresponding to the sections and subsections of this Agreement.
Disclosure of any fact or item in any section of the Company Disclosure Schedule
shall not, should the existence of the

                                       44

<PAGE>

fact or item or its contents be relevant to any other section of the Company
Disclosure Schedule, be deemed to be disclosed with respect to such sections.

     10.3  Certain Definitions. For purposes of this Agreement, the term:

           (a)  "Affiliates" means, with respect to any Person, any other Person
that directly or indirectly, through one or more intermediaries, controls, is
controlled by, or is under common control with, the first mentioned Person;
including, without limitation, any partnership or joint venture in which the
Company (either alone, or through or together with any other Subsidiary) has,
directly or indirectly, an interest of 15% or more of the issued and outstanding
capital stock or other equity interests of such Person;

           (b)  "Business Day" means any day other than a Saturday, Sunday or
day on which banks are permitted to close in the State of Alabama or in the
State of Delaware.

           (c)  "Control" (including the terms "controlled by" and "under common
control with") means the possession, directly or indirectly, of the power to
direct or cause the direction of the management or policies of a Person, whether
through the ownership of stock, as trustee or executor, by contract or credit
arrangement or otherwise;

           (d)  "Court" means any court or arbitration tribunal of the United
States, any domestic state, or any foreign country, and any political
subdivision thereof.

           (e)  "Environmental Claim" means any claim, action, cause of action,
investigation or notice by any Person alleging potential liability (including,
without limitation, potential liability for investigatory costs, cleanup costs,
governmental response costs, natural resources damages, property damages,
personal injuries or penalties) arising out of, based on or resulting from (a)
the presence, release or disposal of any Hazardous Materials at any location,
whether or not owned or operated by the Company, or (b) circumstances forming
the basis of any violation, or alleged violation, of any Environmental Law.

           (f)  "Environmental Laws" means any Law pertaining to: (i) the
protection of health, safety and the indoor or outdoor environment; (ii) the
conservation, management or use of natural resources and wildlife; (iii) the
protection or use of surface water and ground water; (iv) the management,
manufacture, possession, presence, use, generation, transportation, treatment,
storage, disposal, release, threatened release, abatement, removal, remediation
or handling of, or exposure to, any Hazardous Material; or (v) pollution
(including any release to air, land, surface water and ground water); and
includes, without limitation, the Comprehensive Environmental, Response,
Compensation, and Liability Act of 1980, as amended, and the Regulations
promulgated thereunder and the Solid Waste Disposal Act, as amended, 42 U.S.C.
ss.ss. 6901 et seq.

           (g)  "Exchange Agent" means Mintz, Levin, Cohn, Ferris, Glovsky and
Popeo, P.C. or any other entity appointed to act in the capacities required
under Section 1.10.

           (h)  "Governmental Authority" means any governmental agency or
authority (other than a Court) of the United States, any domestic state, or any
foreign country, and any

                                       45

<PAGE>

political subdivision or agency thereof, and includes any authority having
governmental or quasi-governmental powers.

            (i)  "Hazardous Material" means any substance, chemical, compound,
product, solid, gas, liquid, waste, by-product, pollutant, contaminant or
material which is hazardous or toxic and is regulated under any Environmental
Law, and includes without limitation, asbestos or any substance containing
asbestos, polychlorinated biphenyls or petroleum (including crude oil or any
fraction thereof).

            (j)  "Intellectual Property Right" has the meaning ascribed to such
term in Section 2.22 of this Agreement.

            (k)  "Knowledge" means (i) in the case of an individual, the actual
knowledge possessed by the individual of a particular fact or other matter,
after making due inquiry, or (ii) in the case of an entity (other than an
individual), such entity will be deemed to have "Knowledge" of a particular fact
or other matter if any individual who is serving as a director, officer,
partner, in-house counsel, patent counsel (with respect to Intellectual Property
Rights only), executor or trustee of such entity (or in any similar capacity)
has, or at any time had, after due inquiry, actual knowledge of such fact or
other matter.

            (l)  "Law" means all laws, statutes and ordinances of any
Governmental Authority, including all decisions of Courts having the effect of
law in each such jurisdiction;

            (m)  "Lien" means any mortgage, pledge, security interest,
attachment, encumbrance, lien (statutory or otherwise), option, conditional sale
agreement, right of first refusal, first offer, termination, participation or
purchase or charge of any kind (including any agreement to give any of the
foregoing); provided, however, that the term "Lien" shall not include (i)
statutory liens for Taxes, which are not yet due and payable or are being
contested in good faith by appropriate proceedings, (ii) statutory or common law
liens to secure landlords, lessors or renters under leases or rental agreements
confined to the premises rented, (iii) deposits or pledges made in connection
with, or to secure payment of, workers' compensation, unemployment insurance,
old age, pension or other social security programs mandated under applicable
Laws, (iv) statutory or common law liens in favor of carriers, warehousemen,
mechanics and materialsmen, to secure claims for labor, materials or supplies
and other like liens, and (v) restrictions on transfer of securities imposed by
applicable state and federal securities Laws;

            (n)  "Litigation" means any suit, action, arbitration, cause of
action, claim, complaint, criminal prosecution, investigation, demand letter, or
governmental or other administrative proceeding, whether at law or at equity,
before or by any Governmental Authority, Court or other tribunal;

            (o)  "Material Adverse Effect" means any fact, event, change,
circumstance or effect that is materially adverse to the business, condition
(financial or otherwise), operations, results of operations, assets, liabilities
or prospects of (i) the Company (prior to the Effective Time) or the Surviving
Corporation (after the Effective Time, but based on the business, condition
(financial or otherwise), operations, result of operations, assets, liabilities
or prospects

                                       46

<PAGE>

of the Surviving Corporation as of the Effective Time) when such term is used in
a representation or warranty of, or otherwise in relation to, the Company, or
the context otherwise so requires, or (ii) QIAGEN or any of its subsidiaries
when such term is used in relation to QIAGEN, Merger Sub or the Surviving
Corporation, or the context otherwise so requires.

            (p)  "Order" means any judgment, order, writ, injunction or decree
of any Court or Governmental Authority.

            (q)  "Person" means an individual, corporation, partnership,
association, trust, unincorporated organization, limited liability company,
other entity or group (as defined in Section 13(d)(3) of the Exchange Act);

            (r)  "Regulation" means any rule or regulation of any Governmental
Authority having the effect of Law.

            (s)  "Related Agreements" means the Release Agreements, the
Shareholder Agreements, the Escrow Agreement, the Restriction Agreement, the
Option Agreement, the Declaration, the Subscription Agreement and the New XAG
License Agreement.

            (t)  "Subsidiary" or "Subsidiaries" of the Company, the Surviving
Corporation, QIAGEN or any other Person means any corporation, partnership,
joint venture, limited liability company or other legal entity of which the
Company, the Surviving Corporation, QIAGEN or such other Person, as the case may
be, either alone or through or together with any other Subsidiary, owns,
directly or indirectly, 50% or more of the stock or other equity interests the
holders of which are generally entitled to vote for the election of the board of
directors or other governing body of such corporation or other legal entity.

     10.4   Interpretation. When a reference is made in this Agreement to
Sections, subsections, Schedules or Exhibits, such reference shall be to a
Section, subsection, Schedule or Exhibit to this Agreement unless otherwise
indicated. The words "include," "includes" and "including" when used herein
shall be deemed in each case to be followed by the words "without limitation."
The word "herein" and similar references mean, except where a specific Section
or Article reference is expressly indicated, the entire Agreement rather than
any specific Section or Article. The table of contents and the headings
contained in this Agreement are for reference purposes only and shall not affect
in any way the meaning or interpretation of this Agreement.

     10.5   Severability. If any term or other provision of this Agreement is
determined by a Court of competent jurisdiction, without further opportunity to
appeal, to be invalid, illegal or incapable of being enforced in any respect,
then such term or provision shall be deemed to be limited to the extent that
such Court determines it enforceable, and as so limited shall remain in full
force and effect, and all other terms and provisions of this Agreement shall
remain in full force and effect. In the event that such Court shall determine
any such provision, or any portion thereof, to be wholly unenforceable, all
other terms and provisions of this Agreement shall nevertheless remain in full
force and effect. Upon any determination that any term or other provision, or
portion thereof, is invalid, illegal or incapable of being enforced, the parties
hereto shall negotiate in good faith to modify this Agreement so as to effect
the original intent of the

                                       47

<PAGE>

parties as closely as possible in an acceptable manner to the end that
transactions contemplated hereby are fulfilled to the extent possible.

            10.6   Entire Agreement. This Agreement (including all exhibits and
schedules hereto) constitutes the entire agreement of the parties hereto and
supersedes all prior agreements and undertakings (other than the Confidentiality
Agreement), both written and oral, among the parties, or any of them, with
respect to the subject matter hereof and, except as otherwise expressly provided
herein, is not intended to confer upon any other Person any rights or remedies
hereunder.

            10.7   Assignment. This Agreement shall not be assigned by operation
of law or otherwise, except that QIAGEN and Merger Sub may assign all or any of
their rights hereunder to any Affiliate, provided that no such assignment shall
relieve the assigning party of its obligations hereunder.

            10.8   Parties in Interest. This Agreement shall be binding upon and
inure solely to the benefit of each party hereto, and nothing in this Agreement,
express or implied, is intended to or shall confer upon any other Person any
right, benefit or remedy of any nature whatsoever under or by reason of this
Agreement.

            10.9   Failure or Indulgence Not Waiver; Remedies Cumulative. No
failure or delay on the part of any party hereto in the exercise of any right
hereunder will impair such right or be construed to be a waiver of, or
acquiescence in, any breach of any representation, warranty or agreement herein,
nor will any single or partial exercise of any such right preclude other or
further exercise thereof or of any other right. All rights and remedies existing
under this Agreement are cumulative to, and not exclusive to, and not exclusive
of, any rights or remedies otherwise available.

            10.10  Governing Law. This agreement and the agreements, instruments
and documents contemplated hereby will be governed by and construed in
accordance with the Law of the State of Delaware (exclusive of conflicts of law
principles) ("Delaware Law"). Delaware Courts within the State of Delaware and,
more particularly, to the fullest extent such Court shall have subject matter
jurisdiction over the matter, the Court of Chancery of the State of Delaware,
will have exclusive jurisdiction over any and all disputes between the parties
hereto, whether in law or equity, arising out of or relating to this Agreement
and the agreements, instruments and documents contemplated hereby. The parties
consent to and agree to submit to the jurisdiction of such Courts, provided,
however, that such consent to jurisdiction is solely for the purpose referred to
in this Section 9.10 and shall not be deemed to be a general submission to the
jurisdiction of such Courts or in the State of Delaware other than for such
purpose. Each of the parties hereby waives, and agrees not to assert in any such
dispute, to the fullest extent permitted by applicable Delaware Law, any claim
that (i) such party is not personally subject to the jurisdiction of such
Courts, (ii) such party and such party's property is immune from any legal
process issued by such Courts or (iii) any Litigation commenced in such Courts
is brought in an inconvenient forum.

            10.11  Counterparts. This Agreement may be executed in one or more
counterparts, and by the different parties hereto in separate counterparts, each
of which when executed shall be

                                       48

<PAGE>

deemed to be an original, but all of which taken together shall constitute one
and the same agreement.

                  [Remainder of page intentionally left blank]

                                       49

<PAGE>

         IN WITNESS WHEREOF, QIAGEN, Merger Sub, the Company and the Company
Shareholders have caused this Agreement and Plan of Merger to be executed as of
the date first written above, in the case of corporations, by their respective
officers thereunto duly authorized.

                               QIAGEN N.V.

                               By   /s/ Peer Schatz
                                  ---------------------------------------
                               Name:  Peer Schatz
                               Title: Managing Director and Chief Financial
                                      Officer


                               XENOPUS MERGER SUB, INC.

                               By   /s/ Peer Schatz
                                  ---------------------------------------
                               Name:  Peer Schatz
                               Title: Treasurer


                               XERAGON, INC.

                               By   /s/ Patrick A. Weiss
                                  ---------------------------------------
                               Name:  Patrick A. Weiss
                               Title: President

                                       50

<PAGE>



COMPANY SHAREHOLDERS:


   /s/ Patrick Weiss                            /s/ Violette Weiss
- -------------------------------------       ------------------------------------
Name:  Patrick Weiss                        Name:  Violette Weiss
Address: 10007 Bluff Drive                  Address:  10007 Bluff Drive
        -----------------------------               ----------------------------
         Huntsville, AL 35803                         Huntsville, AL 35803
        -----------------------------               ----------------------------


   /s/ Stefan Pitsch                            /s/ James R. Hudson, III
- -------------------------------------       ------------------------------------
Name:  Stefan Pitsch                        Name:  James R. Hudson, III
Address: AV Vinet 7                         Address:  127 Holmes Ave, NW
        -----------------------------               ----------------------------
         6H-1004 Lausanne                             Huntsville AL 35801
        -----------------------------               ----------------------------


   /s/ Cindy H. Jackson                         /s/ Edgar Rutishauser
- -------------------------------------       ------------------------------------
Name:  Cindy H. Jackson                     Name: Edgar Rutishauser
Address: 127 Holmes Ave, NW                 Address:  Albisriederstrasse 377
        -----------------------------               ----------------------------
         Huntsville AL 35801                          8047 Zurich
        -----------------------------               ----------------------------


   /s/ Rolf Stalder                             /s/ James R. Hudson, Jr.
- -------------------------------------       ------------------------------------
Name:  Rolf Stalder                         Name:  James R. Hudson, Jr.
Address: Residence la Maison                Address:  127 Holmes Ave, NW
        -----------------------------               ----------------------------
         6363 Burgenstock/NW                          Huntsville AL 35801
        -----------------------------               ----------------------------
         Switzerland
        -----------------------------


  /s/ Susanne J. Hudson                         /s/ Luzi Jenny
- -------------------------------------       ------------------------------------
Name:  Suanne J. Hudson                     Name:  Luzi Jenny
Address: 127 Holmes Ave, NW                 Address:  Rotwandstrasse 65
        -----------------------------               ----------------------------
         Huntsville, AL 35801                         8004 Zurich
        -----------------------------               ----------------------------

                                       51

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>4
<FILENAME>dex51.txt
<DESCRIPTION>OPINION OF DE BRAUW BLACKSTONE
<TEXT>
<PAGE>
                                                                     Exhibit 5.1

To: Qiagen N.V.
Spoorstraat 50
5911 KJ  Venlo
The Netherlands

J.J.J. Schutte - advocaat
Amsterdam, 28 June 2002
Our ref.:       f:\396\20218214\l006-1079.doc\

Dear Sirs,

                                   Qiagen N.V.

Offer and sale of shares

1    Introduction

     I have acted on behalf of De Brauw Blackstone Westbroek N.V. as Dutch legal
     adviser (advocaat) to Qiagen N.V., with corporate seat in Venlo, (the
     "Company") in connection with the registration (the "Registration") by the
     Company with the United States Securities and Exchange Commission (the
     "SEC") of the Additional Shares (as defined below).

2    Dutch Law

     This opinion is limited to Dutch law as applied by the Dutch courts and
     published and in effect on the date of this opinion. It is given on the
     basis that all matters relating to it will be governed by, and that it
     (including all terms used in it) will be construed in accordance with,
     Dutch law.

<PAGE>

3    Scope of Inquiry

     For the purpose of this opinion, I have examined the following documents:

3.1  A print of an e-mailed copy received by me on 1 April 2002 of an executed
     agreement and plan of merger, with the exception of its exhibits, dated 28
     March 2002, between the Company, Xenopus Merger Sub, Inc and Xeragon, Inc.
     (the "Merger Agreement").

3.2  A faxed copy of an executed Subscription Agreement, dated 17 April 2002,
     between the Company and the persons named in it relating to the issuance of
     564,334 ordinary shares in the share capital of the Company (the
     "Additional Shares"), (the "Subscription Agreement").

3.3  A faxed copy of a registration statement on Form F-3 relating to the
     Registration, as filed or to be filed with the SEC (excluding the documents
     incorporated in the registration statement by reference and any annexes to
     it) (the "Registration Statement").

3.4  A photocopy of a notarial copy of the deed of incorporation of the Company
     and its articles of association as most recently amended on 3 July 2000
     according to the trade register extract referred to in paragraph 3.5, both
     as filed with the chamber of commerce and industry for Venlo (the "Chamber
     of Commerce").

3.5  A faxed copy of a trade register extract regarding the Company and provided
     by the Chamber of Commerce and dated 19 June 2000.

3.6  A photocopy of an extract from the minutes of the Company's general meeting
     of shareholders held on 13 June 2001, including a resolution to designate
     the Company's supervisory board (raad van commissarissen) as the corporate
     body authorised to resolve to issue shares and to limit or exclude
     pre-emptive rights (voorkeursrechten) in respect thereof.

3.7  A faxed copy of a written resolution of the Company's managing board
     (directie) dated 28 March 2002.

3.8  A faxed copy of a written resolution of the Company's supervisory board
     (raad van commissarissen) dated 15 February 2002 relating to the issuance
     of up to 666,667 ordinary shares, nominal value EUR 0,01 in the Company's
     share capital, designating Mr M. Colpan and Mr P. Schatz each individually,
     as the authorized persons to resolve upon inter alia the exact number of
     ordinary shares to be issued and to the exclusion of pre-emptive rights in
     connection with the issuance of these ordinary shares.

     In addition, I have obtained the following confirmations given by telephone
     on the date of this opinion:

                                       2

<PAGE>

3.9  Confirmation from the Chamber of Commerce that the trade register extract
     referred to in this paragraph 3 is up to date.

3.10 Confirmation from the office of the bankruptcy division
     (faillissementsgriffie) of the Roermond district court that the Company is
     not registered as having been declared bankrupt or granted suspension of
     payments.

3.11 In this opinion:

     "Agreements" means the Merger Agreement and the Subscription Agreement.

     My examination has been limited to the text of the documents and I have not
     investigated the meaning and effect of any document governed by a law other
     than Dutch law under that other law.

4    Assumptions

4.1  All copy documents conform to the originals and all originals are genuine
     and complete.

4.2  Each signature is the genuine signature of the individual concerned.

4.3  Any minutes and extracts from minutes referred to in paragraph 3 are a true
     record of the proceedings described in them in duly convened, constituted
     and quorate meetings and the resolutions set out in those minutes and any
     written resolutions referred to in paragraph 3 (i) were validly passed and
     remain in full force and effect without modification, and (ii) comply with
     the requirements of reasonableness and fairness (redelijkheid en
     billijkheid) under Dutch law. Any confirmations referred to in paragraph 3
     are true.

4.4  The Agreements are within the capacity and powers of, and have been validly
     authorised and signed by, each party (including the Company).

4.5  When validly signed by all the parties, the Merger Agreement is valid,
     binding and enforceable on each party under Delaware law by which it is
     expressed to be governed, and the Subscription Agreement is valid binding
     and enforceable on each party under applicable law.

4.6  The execution of the Subscription Agreement by Mr P. Schatz on behalf of
     the Company also constitutes his resolution upon the exact number of
     ordinary shares to be issued, as referred to in paragraph 3.8.

4.7  There are no dealings between the parties which affect the Agreements.

4.8  At the time of the issue of the Additional Shares, the Company's authorised
     share capital was sufficient to allow for the issue.

                                       3

<PAGE>

4.9  The Additional Shares have been issued as required under the Company's
     articles of association in force at the time of issue and have been validly
     accepted by the subscribers for them.

4.10 The Additional Shares have been fully paid in accordance with the
     Agreements.

4.11 The Registration Statement has been or will have been filed with the SEC in
     the form referred to in paragraph 3.

4.12 The Additional Shares have been offered on issue, and any announcement of
     such offer has been made, in accordance with the 1995 Act on the
     Supervision of the Securities Trade (Wet toezicht effectenverkeer 1995).

4.13 At the time of their entry into the Agreements and the issue and offer of
     the Additional Shares, no party possessed insider knowledge
     (voorwetenschap) in respect of the Company or the trade in its securities.

5    Opinion

     Based on the documents and confirmations referred to and the assumptions in
     paragraphs 3 and 4 and subject to the qualifications in paragraph 6 and to
     any matters not disclosed to me, I am of the following opinion:

5.1  The Additional Shares have been validly issued in accordance with Dutch law
     and are fully paid.

6    Qualifications

     This opinion is subject to the following qualifications:

6.1  This opinion is subject to any limitations arising from bankruptcy,
     insolvency, liquidation, moratorium, reorganisation and other laws of
     general application relating to or affecting the rights of creditors.

6.2  The trade register extract referred to in paragraph 3 does not provide
     conclusive evidence that the facts set out in it are correct. However,
     under the 1996 Trade Register Act (Handelsregisterwet 1996), subject to
     limited exceptions, a company cannot invoke the incorrectness or
     incompleteness of its trade register registration against third parties who
     were unaware of it.

6.3  The confirmation from the office of the bankruptcy division referred to in
     paragraph 3 does not provide conclusive evidence that the Company has not
     been declared bankrupt or granted suspension of payments.

                                       4

<PAGE>

7    Reliance

     This opinion is solely for your benefit and solely for the purpose of the
     Registration. It is not to be transmitted to anyone else nor is it to be
     relied upon by anyone else of for any other purpose or quoted or referred
     to in any public document or filed with anyone without my written consent
     except that it may be filed with the SEC as an exhibit to the Registration
     Statement (but I do not admit that I am a person whose consent for that
     filing and reference is required under Section 7 of the United States
     Securities Act of 1933, as amended).

Yours faithfully,

/s/ J.J.J. Schutte
- ------------------
J.J.J. Schutte
for De Brauw Blackstone Westbroek N.V.


                                       5

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-8.1
<SEQUENCE>5
<FILENAME>dex81.txt
<DESCRIPTION>OPINION OF BAKER & MCKENZIE
<TEXT>
<PAGE>

                                                                     Exhibit 8.1

                                                          WILLEM C.B. VAN WETTUM
                                                                     020-5517414

QIAGEN N.V.
Spoorstraat 50
5911 KJ  VENLO
The Netherlands

June 24, 2002
68-083443-0/WCW/FFR

Re: Qiagen N.V. Secondary Public Offering by Certain Selling Shareholders

Dear Sirs,

We have acted as Netherlands tax counsel to QIAGEN N.V., a Netherlands
corporation (the "Company"), in connection with the secondary public offering by
certain selling shareholders of the Common Shares in the Company which is
described in the Registration Statement on Form F-3, as filed with the
Securities and Exchange Commission ("the Prospectus") and in certain documents
incorporated by reference into the Prospectus. All capitalized terms, unless
otherwise specified, have the meaning assigned to them in the Prospectus.

We express no opinion as to any laws other than the current Netherlands tax laws
and regulations. There can be no assurance that a change in the existing laws
and regulations would not occur in the future which may have the effect of
altering our opinion.

Based upon and subject to the foregoing we are of the opinion that the
statements in the Company's Annual Report on Form 20-F for the fiscal year ended
December 31, 2001 (a copy of which is attached), under the caption "Taxation --
Netherlands Tax Considerations", incorporated by reference into the Prospectus,
summarize the

                                                                             1/2

<PAGE>

                                                                             2/2
June 24, 2002

material tax consequences under Netherlands laws of an investment in the Common
Shares.

In this opinion, Netherlands legal and fiscal concepts are expressed and
described in English language terms and not in their original Netherlands
language terms. These concepts may not be identical to the concepts described by
the equivalent English language terms.

This opinion is furnished to you and may not be relied upon by, transmitted to
or filed with any person, firm or company or institution without our prior
written consent. We hereby consent to the filing of this opinion as an exhibit
to the Registration Statement. We also consent to the incorporation by reference
of this consent into any subsequent registration statement filed pursuant to
Rule 462(b) under the Securities Act of 1933 in connection with the offering to
which the Registration Statement relates. We also consent to the references to
Baker & McKenzie under the headings "Taxation -- Netherlands Tax Considerations"
and "Legal Matters" in the Registration Statement.

This opinion is strictly limited to the matters stated herein and is not to be
read as extending by implication to any matters not specifically referred to
herein.

Yours sincerely,

/s/ Baker & McKenzie
Baker & McKenzie
Willem C.B. van Wettum

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-8.2
<SEQUENCE>6
<FILENAME>dex82.txt
<DESCRIPTION>OPINION OF MINTZ,LEVIN
<TEXT>
<PAGE>

                                                                     EXHIBIT 8.2

                                  June 28, 2002

QIAGEN N.V.
Spoorstraat 501
5911 KJ Venlo
The Netherlands

Ladies and Gentlemen:

         You have requested our opinion regarding certain United States federal
income tax consequences of the ownership of the Common Shares (the "Shares") of
QIAGEN N.V., a Netherlands public limited liability company (the "Company"),
acquired pursuant to a public offering (the "Offering") of the Shares in the
United States.

         In formulating our opinion as to the matters certified, we have
examined such documents as we have deemed appropriate, including the
Registration Statement of the Company on Form F-3 as filed with the Securities
and Exchange Commission ("Commission") pursuant to the Securities Act of 1933
(the "Securities Act") on June ___, 2002 (such Registration Statement being
referred to hereinafter as the "Registration Statement") and the Company's
Annual Report on Form 20-F for the fiscal year ended December 31, 2001 as filed
with the Commission on April 2, 2002 (the "Form 20-F"). Also, we have obtained
such additional information as we have deemed relevant and necessary through
consultation with various officers and representatives of the Company.

         The terms of the Offering, which are set forth in the Registration
Statement, are incorporated herein by reference.

         Based upon the terms of the Offering, as set forth in the Registration
Statement, it is our opinion that the portion of the Form 20-F set forth under
the heading "Taxation - United States Federal Income Tax Considerations",
incorporated by reference into the Registration Statement, summarizes the
material United States federal income tax consequences to U.S. Holders and to
non-U.S. Holders (as defined therein) of the acquisition, ownership and
disposition of Shares acquired in the Offering.

         The foregoing opinion is based on current provisions of the United
States Internal Revenue Code of 1986, as amended, the Treasury Regulations
promulgated thereunder (including proposed Treasury Regulations), published
pronouncements of the Internal Revenue Service, and case law, any of which may
be changed at any time with retroactive effect. No opinion is expressed on any
matters other than those specifically referred to herein.

                                       1

<PAGE>

                                                                     EXHIBIT 8.2

         We hereby consent to your filing this opinion as an exhibit to the
Registration Statement and to the reference to our firm therein. We also consent
to the incorporation by reference of this opinion into any subsequent
registration statement filed pursuant to Rule 462(b) under the Securities Act in
connection with the offering to which the Registration Statement relates.

                         Very truly yours,

                         /S/ Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                         -------------------------------------------------------

                         Mintz, Levin, Cohn, Ferris,
                           Glovsky and Popeo, P.C.

                                       2

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>7
<FILENAME>dex991.txt
<DESCRIPTION>PRESS RELEASE
<TEXT>
<PAGE>

                                                                    Exhibit 99.1

Peer M. Schatz, Chief Financial Officer, QIAGEN N.V., +49 2103 2911 702, e-mail:
p.schatz@de.QIAGEN.com
Dr. Solveigh Mahler, Manager Investor Relations, QIAGEN N.V., +49 2103 2911 710,
e-mail: s.maehler@de.QIAGEN.com
Noonan/Russo Communications, +1 212 696 4455, Mary Claire Bice (Investors)

QIAGEN Acquires Xeragon, Inc.

Technologies for the Manufacture and Use of Synthetic RNA Add a Rapidly Growing
Segment of Synthetic Nucleic Acid Products

Venlo, the Netherlands and Huntsville, Alabama, USA - April 18, 2002: QIAGEN
N.V. (Nasdaq: QGENF, Frankfurt, Neuer Markt: QIA) today announced that it has
completed the acquisition of Xeragon, Inc. Xeragon, a privately held company, is
a market and technology leader for products and services focusing on synthetic
RNA and in particular siRNA. The acquisition of this technology and product
portfolio adds an exciting segment to QIAGEN Operon's leadership position in
synthetic DNA products.

Subject to the terms of the merger agreement, QIAGEN issued approximately
564,000 shares of its common stock (valued at approximately US$ 8 million) in
exchange for all of the outstanding capital stock of Xeragon Inc. In addition,
QIAGEN could issue an additional payment of up to US$ 1.2 million in cash or
stock in December 2003 upon the attainment of certain performance targets.
QIAGEN expects this transaction to have a positive and accretive impact on
QIAGEN's 2003 net income per share. Xeragon's activities will be integrated into
QIAGEN Sciences' operations in Germantown, Maryland.

Nucleic acids take two forms: DNA and RNA. Synthetic DNA is today widely used in
many different molecular biology applications. Only very recently
state-of-the-art applications emerged which require large amounts of synthetic
RNA. Small interfering RNA (siRNA) is double stranded RNA of 21-25 nucleotides
in length. siRNAs have been shown to function as key molecules in triggering
sequence specific mRNA degradation leading to the posttranscriptional
'silencing' of a target gene. The siRNA technology is considered as the most
powerful tool to unravel function of genes. It can be used in a variety of
applications such as high throughput target validation and gene therapy.

Xeragon's core competencies include RNA amidite and synthesis technology based
on a proprietary chemistry (TOM amidites), which in terms such as quality and
cost allow a highly efficient manufacturing process of RNA. Xeragon has built a
leading position in RNA synthesis and in gene silencing by siRNA technology,
which has been co-exclusively licensed in from the Massachusetts Institute of
Technology. Xeragon offers custom and pre-manufactured stock siRNA products.
QIAGEN and Xeragon believe that these RNA synthesis technologies can soon be
integrated into QIAGEN Operon's leading massive parallel, high throughput DNA
synthesis platforms. The newly emerging market for synthetic RNA is growing
rapidly. QIAGEN expects this product line to contribute approximately US$ 1
million in net sales and a net loss of approximately $1 million in the second
half of 2002 and US$ 4 million in net sales and US$ 1 million in net income in
2003.

"Xeragon's proprietary RNA technologies integrate well with QIAGEN's massive
parallel, high throughput DNA synthesis platform and extend QIAGEN's presence
into one of the most dynamic areas of today's functional genomics market," said
Dr. Ulrich Schriek, Vice President Corporate Business Development of QIAGEN.
"Xeragon's siRNA combine seamlessly with

<PAGE>

QIAGEN's RNA purification technologies and RNA transfection products as well
with our analytical tools for quantifying the effected RNA molecules. We are
very impressed by Xeragon's proprietary technologies and by the fact that the
company has already demonstrated its commercial potential as evidenced by an
impressive list of existing customer contacts."

"Xeragon is currently faced with a significant customer demand from the leading
genomics and pharmaceutical customers for its products." added Patrick A. Weiss,
Chairman and CEO of Xeragon. "In joining forces with the technology,
manufacturing and marketing strength of the QIAGEN group, we believe we now have
the best opportunity to build a significant commercial presence for our patented
technologies in this rapidly growing and exciting market."

Xeragon Inc. was established in September of 2001 and employs today
approximately 10 people at its facilities in Alabama. Further information on
Xeragon can be found at www.xeragon.com.

About QIAGEN

QIAGEN N.V., a Netherlands holding company with subsidiaries in Germany, the
United States, Japan, the United Kingdom, Switzerland, France, Italy, Australia
and Canada, believes it is the world's leading provider of innovative enabling
technologies and products for the separation, purification and handling of
nucleic acids. The Company has developed a comprehensive portfolio of more than
320 proprietary, consumable products for nucleic acid separation, purification
and handling, nucleic acid amplification, as well as automated instrumentation,
synthetic nucleic acid products and related services. QIAGEN's products are sold
in more than 42 countries throughout the world to academic research markets and
to leading pharmaceutical and biotechnology companies. In addition, the Company
is positioning its products for sale into developing commercial markets,
including DNA sequencing and genomics, nucleic acid-based molecular diagnostics,
and genetic vaccination and gene therapy. QIAGEN employs approximately 1,500
people worldwide. Further information on QIAGEN can be found at www.QIAGEN.com.

Certain of the statements contained in this news release may be considered
forward-looking statements within the meaning of Section 27A of the U.S.
Securities Act of 1933, as amended, and Section 21E of the U.S. Securities
Exchange Act of 1934, as amended. To the extent that any of the statements
contained herein relating to QIAGEN's products and markets and operating results
are forward-looking, such statements are based on current expectations that
involve a number of uncertainties and risks. Such uncertainties and risks
include, but are not limited to, risks associated with management of growth and
international operations (including the effects of currency fluctuations),
variability of operating results, the successful integration of acquisitions,
the commercial development of the DNA sequencing, genomics and synthetic nucleic
acid-related markets (including the market for products produced by the business
of Xeragon, Inc. being acquired), nucleic acid-based molecular diagnostics
market, and genetic vaccination and gene therapy markets, competition, rapid or
unexpected changes in technologies, fluctuations in demand for QIAGEN's products
(including seasonal fluctuations), difficulties in successfully adapting
QIAGEN's products to integrated solutions and producing such products, the
ability of each of QIAGEN to identify and develop new products and to
differentiate its products from competitors, and the integration of acquisitions
of technologies and businesses. For further information, refer to the discussion
in reports that QIAGEN has filed with the U.S. Securities and Exchange
Commission (SEC).

                                       ###

</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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