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<TYPE>EX-99.1
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<FILENAME>dex991.txt
<DESCRIPTION>PRESS RELEASE
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                                                                    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

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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).

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