
<PAGE>   1
                                                                   EXHIBIT 10.16

                                 STERITECH, INC.

                              AMENDED AND RESTATED
                           INVESTORS' RIGHTS AGREEMENT
<PAGE>   2
                                TABLE OF CONTENTS

<TABLE>
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                                                                                                                 PAGE
<S>                                                                                                              <C>
I.                DEFINITIONS...................................................................................  1

II.               REGISTRATION; RESTRICTIONS ON TRANSFER........................................................  3
         2.1      Restrictions on Transfer......................................................................  4
         2.2      Demand Registration...........................................................................  5
         2.3      Piggyback Registrations.......................................................................  7
         2.4      Form S-3 Registration.........................................................................  8
         2.5      Obligations of the Company....................................................................  9
         2.6      Termination of Registration Rights............................................................ 10
         2.7      Furnish Information........................................................................... 10
         2.8      Delay of Registration......................................................................... 10
         2.9      Indemnification............................................................................... 10
         2.10     Assignment of Registration Rights............................................................. 12
         2.11     "Market Stand-Off" Agreement.................................................................. 13
         2.12     Amendment of Registration Rights.............................................................. 13
         2.13     Limitation on Subsequent Registration Rights.................................................. 13

III.              COVENANTS OF THE COMPANY...................................................................... 14
         3.1      Basic Financial Information and Reporting..................................................... 14
         3.2      Inspection Rights............................................................................. 14
         3.3      Confidentiality of Records.................................................................... 15
         3.4      Insurance..................................................................................... 15
         3.5      Proprietary Information Agreements............................................................ 15
         3.6      Employee Agreements........................................................................... 15
         3.7      Observer Rights............................................................................... 16
         3.8      Termination of Covenants...................................................................... 16

IV.               RIGHTS OF FIRST REFUSAL....................................................................... 16
         4.1      Subsequent Offerings.......................................................................... 16
         4.2      Exercise of Rights............................................................................ 16
         4.3      Issuance of Equity Securities to Other Persons................................................ 17
         4.4      Termination of Rights of First Refusal........................................................ 17
         4.5      Transfer of Rights of First Refusal........................................................... 17
         4.6      Excluded Securities........................................................................... 17

V.                MISCELLANEOUS................................................................................. 18
         5.1      Governing Law................................................................................. 18
         5.2      Survival...................................................................................... 18
         5.3      Successors and Assigns........................................................................ 18
         5.4      Separability.................................................................................. 19
         5.5      Amendment and Waiver.......................................................................... 19
         5.6      Delays or Omissions........................................................................... 19
</TABLE>


                                       i.
<PAGE>   3
                                TABLE OF CONTENTS
                                   (CONTINUED)

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                                                                                                                PAGE
        <S>      <C>                                                                                                    <C>
         5.7      Notices, etc.................................................................................. 19
         5.8      Attorneys' Fees............................................................................... 20
         5.9      Titles and Subtitles.......................................................................... 20
         5.10     Counterparts.................................................................................. 20
</TABLE>


                                       ii.
<PAGE>   4
                              AMENDED AND RESTATED
                           INVESTORS' RIGHTS AGREEMENT

         THIS AMENDED AND RESTATED INVESTORS' RIGHTS AGREEMENT (the "Agreement")
is entered into as of the 1st day of April, 1996, by and among (i) STERITECH,
INC., a California corporation (the "Company"), (ii) the purchasers of the
Company's Series A Preferred Stock ("Series A Stock") and warrants exercisable
for shares of the Company's Series B Preferred Stock (the "Series B Stock")
pursuant to that certain Series A Preferred Stock Purchase Agreement/Series B
Preferred Stock Warrant Agreement dated as of December 27, 1991 (the "Series
A/Series B Purchasers"), (iii) the purchasers of the Company's Series C
Preferred Stock (the "Series C Stock") pursuant to those certain Series C
Preferred Stock Purchase Agreements dated as of December 10, 1993 and March 14,
1994 (the "Series C Purchasers"), (iv) the purchasers of the Company's Series D
Preferred Stock (the "Series D Stock") pursuant to that certain Series D
Preferred Stock Purchase Agreement dated as of March 1, 1995 (the "Series D
Purchasers"), (v) the purchasers of warrants for Series B Stock and Series C
Stock pursuant to those certain Note and Warrant Purchase Agreements dated May
14, 1993 and August 13, 1993 (the "Warrant Holders"), (vi) the purchaser of the
Company's Series E Preferred Stock (the "Series E Stock") pursuant to that
certain Series E Preferred Stock Purchase Agreement dated as of April 1, 1996
(the "Series E Purchaser") and (vii) COMDISCO, INC. ("Comdisco"). Each of the
Series A/Series B Purchasers, the Series C Purchasers, the Series D Purchasers,
the Warrant Holders, the Series E Purchaser and Comdisco, and their transferees,
shall be known as an "Investor".

         In consideration of the mutual agreements, covenants and considerations
and releases contained herein, the parties hereto hereby agree as follows:

                                       I.

                                   DEFINITIONS

         1.1      The term "HOLDER" means:

                  (a)      any person owning of record Registrable Securities 
that have not been sold to the public; or

                  (b)      any assignee of record of such Registrable Securities
in accordance with Section 2.10 of the Agreement; provided, however:

                         (i)        that for purposes of the Agreement, a record
holder of Series A Stock, Series B Stock, Series C Stock, Series D Stock or
Series E Stock convertible into such Registrable Securities shall be treated as
the Holder of such Registrable Securities, except that the record holder of any
of such shares that are issued upon exercise of the warrants originally issued
to Comdisco in connection with leasing transactions: (A) to purchase 20,779
shares of Series A Preferred Stock, (B) to purchase 3,949 shares of Series B
Preferred Stock, (C) to


                                       1.
<PAGE>   5
purchase 6,250 shares of Series C Stock and (D) to purchase 4,500 shares of
Series D Preferred Stock (the "Comdisco Shares") shall be considered a Holder
only for purposes of Sections 2.3 - 2.13 of the Agreement and under those
provisions shall be subject to the same terms and conditions with respect to the
registration and sale of the shares as would any other Holder; and

                        (ii)        that the Company shall in no event be 
obligated to register the Series A Stock, Series B Stock, Series C Stock, Series
D Stock, Series E Stock or the warrants held by the Warrant Holders and
Comdisco, and that Holders of Registrable Securities will not be required to
convert or exercise, respectively, the Series A Stock, Series B Stock, Series C
Stock, Series D Stock, Series E Stock or the warrants held by the Warrant
Holders and Comdisco, into Common Stock in order to exercise registration rights
granted hereunder, until immediately before the closing of the offering to which
the registration relates.

         1.2      The terms "REGISTER," "REGISTERED," and "REGISTRATION" refer 
to an registration effected by preparing and filing a registration statement in
compliance with the Securities Act, and the declaration or ordering of
effectiveness of such registration statement or document.

         1.3      The term "REGISTRABLE SECURITIES" means:

                  (a)      Common Stock of the Company issued or issuable upon 
conversion of:

                         (i)        the Series A Stock issued pursuant to the 
Series A/Series B Purchase Agreement;

                        (ii)        the Series B Stock issued pursuant to those
certain warrants identified on Exhibit A of the Series A/Series B Purchase 
Agreement;

                       (iii)        the Series C Stock issued pursuant to the 
Series C Stock Purchase Agreements dated as of December 10, 1993 and March 14, 
1994;

                        (iv)        the Series B Stock and the Series C Stock 
issued or issuable upon exercise of the warrants issued in connection with the 
May 14 and August 13, 1993 bridge loan financings by the Company;

                         (v)        the Series D Stock issued pursuant to the 
Series D Stock Purchase Agreement dated as of March 1, 1995;

                        (vi)        the equity securities issuable pursuant to 
Sections 4.1 and 4.2 of that certain Development, Manufacturing and Marketing
Agreement, dated as of April 1, 1996, between Baxter Healthcare Corporation, a
Delaware corporation (together with its affiliates (as such term is defined in
the Baxter Agreement), "Baxter"), and the Company (the "Baxter Agreement") and
issued to Baxter pursuant to this Agreement; and

                  (b)      any Common Stock of the Company issued as (or 
issuable upon the conversion or exercise of any warrant, right or other security
which is issued as) a dividend or


                                       2.
<PAGE>   6
other distribution with respect to, or in exchange for or in replacement of,
such above-described securities; and

                  (c)      for purposes of Sections 2.3 - 2.13 of the Agreement,
the term "Registrable Securities" also includes:

                         (i)        Common Stock of the Company issued or 
issuable upon conversion of the Preferred Stock issued pursuant to the exercise
of the warrants to purchase the Comdisco Shares, and

                        (ii)        any Common Stock of the Company issued as 
(or issuable upon the conversion or exercise of any warrant, right or other
security which is issued as) a dividend or other distribution with respect to,
or in exchange for or in replacement of, such above-described securities.

         Notwithstanding the foregoing, Registrable Securities shall not include
any securities sold by a person to the public either pursuant to a registration
statement, Rule 144 or Rule 144A or sold in a private transaction in which the
transferor's rights are not assigned pursuant to Section 2.10 of the Agreement.

         1.4      The number of shares of "REGISTRABLE SECURITIES THEN 
OUTSTANDING" shall be determined by the calculating total number of shares of
the Company's Common Stock that are Registrable Securities and either (1) are
then issued and outstanding or (2) are issuable pursuant to then exercisable or
convertible securities.

         1.5      "SECURITIES ACT" shall mean the Securities Act of 1933, as 
amended.

         1.6      "SECURITIES LAW" shall mean the California Corporate 
Securities Law of 1968, as amended.

         1.7      The term "FORM S-3" means such form under the Securities Act 
as in effect on the date hereof or any successor registration form under the
Securities Act subsequently adopted by the SEC which permits inclusion or
incorporation of substantial information by reference to other documents filed
by the Company with the SEC.

         1.8      The term "SEC" or "COMMISSION" means the Securities and 
Exchange Commission.


                                       3.
<PAGE>   7
                                       II.

                     REGISTRATION; RESTRICTIONS ON TRANSFER

         2.1      RESTRICTIONS ON TRANSFER.

                  (a) Each Holder agrees not to make any disposition of all or
any portion of the Registrable Securities (or the Common Stock issuable upon the
conversion thereof) unless and until the transferee has agreed in writing for
the benefit of the Company to be bound by this Section 2.1 and Section 2.11
hereof, provided and to the extent such Sections are then applicable and:

                                  (i)       There is then in effect a 
registration statement under the Securities Act covering such proposed
disposition and such disposition is made in accordance with such registration
statement; or

                                 (ii)       (A)      Such Holder shall have 
notified the Company of the proposed disposition and shall have furnished the
Company with a detailed statement of the circumstances surrounding the proposed
disposition, and

                                            (B)      if reasonably requested by
the Company, such Holder shall have furnished the Company with an opinion of
counsel, reasonably satisfactory to the Company, that such disposition will not
require registration of such shares under the Securities Act. It is agreed that
the Company will not require opinions of counsel for transactions made pursuant
to Rule 144 except in unusual circumstances.

                                (iii)       Notwithstanding the provisions of 
paragraphs (i) and (ii) above, no such registration statement or opinion of
counsel shall be necessary for a transfer by a Holder which is a partnership to
a partner of such partnership or a retired partner of such partnership who
retires after the date hereof, or to the estate of any such partner or retired
partner or the transfer by gift, will or intestate succession of any partner to
his spouse or to the siblings, lineal descendants or ancestors of such partner
or his spouse, if the transferee agrees in writing to be subject to the terms
hereof to the same extent as if he were an original Holder hereunder.

                  (b) Each certificate representing Series A Stock, Series B
Stock, Series C Stock, Series D Stock, Series E Stock or Registrable Securities
shall (unless otherwise permitted by the provisions of the Agreement) be stamped
or otherwise imprinted with legends substantially similar to the following (in
addition to any legend required under applicable state securities laws or as
provided elsewhere in the Agreement):

         THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
         SECURITIES ACT OF 1933 (THE "ACT") AND MAY NOT BE OFFERED, SOLD OR
         OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS AND UNTIL
         REGISTERED UNDER THE ACT OR, IN THE OPINION OF COUNSEL OR BASED ON
         OTHER WRITTEN EVIDENCE IN FORM AND SUBSTANCE SATISFACTORY TO THE


                                       4.
<PAGE>   8
         ISSUER OF THESE SECURITIES, SUCH OFFER, SALE OR TRANSFER, PLEDGE OR
         HYPOTHECATION IS IN COMPLIANCE THEREWITH.

         THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO A RIGHT OF
         FIRST REFUSAL OPTION IN FAVOR OF THE COMPANY AND/OR ITS ASSIGNEE(S), AS
         PROVIDED IN THE BYLAWS OF THE COMPANY, AND IN FAVOR OF THE OTHER
         STOCKHOLDERS, AS PROVIDED IN THE INVESTORS' RIGHTS AGREEMENT.

                  (c) The Company shall be obligated to reissue promptly
unlegended certificates at the request of any Holder thereof if the Holder shall
have delivered to the Company an opinion of counsel reasonably acceptable to the
Company to the effect that the securities proposed to be disposed of may
lawfully be so disposed of without registration, qualification or legend.

                  (d) Any legend endorsed on an instrument pursuant to
applicable state securities laws and the stop-transfer instructions with respect
to such securities, shall be removed upon receipt by the Company of an order of
the appropriate blue sky authority authorizing such removal.

         2.2      DEMAND REGISTRATION.

                  (a) Subject to the conditions of this Section 2.2, if the
Company shall receive at any time after the earlier of (i) January 15, 1995, or
(ii) one hundred eighty (180) days from the first underwritten public offering
of the Company's Securities (the "Initial Offering"), a written request from the
Holders of not less than thirty percent (30%) of the Registrable Securities Then
Outstanding (the "Initiating Holders") that the Company file a registration
statement under the Securities Act covering the registration of at least twenty
percent (20%) of the Registrable Securities owned by the Initiating Holders (or
any lesser percentage if the anticipated aggregate offering price, net of
underwriting discounts and commission, would exceed $2,000,000), then the
Company shall, within ten (10) days of the receipt thereof, give written notice
of such request to all Holders, and subject to the limitations of Section
2.2(b), effect, as soon as practicable, and in any event within 90 days the
registration under the Securities Act of all Registrable Securities that the
Holders request to be registered in a written request given within twenty (20)
days of the receipt of such notice from the Company.

                  (b) If the Initiating Holders intend to distribute the
Registrable Securities covered by their request by means of an underwriting,
they shall so advise the Company as a part of their request made pursuant to
this Section 2.2 and the Company shall include such information in the written
notice referred to in Section 2.2(a). In such event, the right of any Holder to
include his Registrable Securities in such registration shall be conditioned
upon such Holder's participation in such underwriting and the inclusion of such
Holder's Registrable Securities in the underwriting (unless otherwise mutually
agreed by a majority in interest of the Initiating Holders and such Holder) to
the extent provided herein. All Holders proposing to distribute their securities
through such underwriting shall enter into an underwriting agreement in
customary form with the underwriter or underwriters selected for such
underwriting by a majority in interest of the Initiating Holders.
Notwithstanding any other provision of this Section


                                       5.
<PAGE>   9
2.2, if the underwriter advises the Company in writing that marketing factors
require a limitation of the number of securities to be underwritten (including
Registrable Securities) then the Company shall so advise all Holders of
Registrable Securities which would otherwise be underwritten pursuant hereto,
and the number of shares that may be included in the underwriting shall be
allocated to the Holders of such Registrable Securities (prior to any allocation
to holders of shares other than Registrable Securities) on a pro rata basis
based on the number of Registrable Securities held by all such Holders
(including the Initiating Holders). Any Registrable Securities excluded or
withdrawn from such underwriting shall be withdrawn from the registration, and
the number of shares that may be included in the underwriting shall be
reallocated pursuant to the above allocation formula.

                  (c) The Company is obligated to effect only two (2) such
registrations pursuant to this Section 2.2. A registration pursuant to this
Section 2.2 may be the Initial Offering.

                  (d) The Company shall not be required to effect a registration
pursuant to this Section 2.2 during the period starting with the date of filing
of, and ending on the date 180 days following the effective date of the
registration statement pertaining to the Initial Offering, provided that the
Company is making reasonable and good faith efforts to cause such registration
statement to become effective. In addition, the Company shall not be required to
effect a registration pursuant to this Section 2.2 if within thirty (30) days of
receipt of a written request from Initiating Holders pursuant to Section 2.2(a),
the Company gives notice to the Holders of the Company's intention to make its
Initial Offering and the registration statement pertaining to such Initial
Offering is actually filed within ninety (90) days after such notice.

                  (e) Notwithstanding the foregoing, if the Company furnishes to
Holders requesting a registration statement pursuant to this Section 2.2 a
certificate signed by the President of the Company stating that in the good
faith judgment of the Board of Directors of the Company, it would be seriously
detrimental to the Company and its shareholders for such registration statement
to be filed and it is therefore essential to defer the filing of such
registration statement, the Company shall have the right to defer such filing
for a period of not more than ninety (90) days after receipt of the request of
the Initiating Holders; provided, however, that such right to delay a request
shall be exercised by the Company no more than once in any one-year period.

                  (f) The Company shall bear all the expenses incurred in
connection with the first registration requested pursuant to this Section 2.2
(excluding underwriters' discounts and commissions, which shall be paid by the
selling Holders pro rata), including without limitation all registration,
filing, qualification, printers' and accounting fees, fees and disbursements of
counsel for the Company, and the reasonable fees and disbursements of one
special counsel for the selling Holders; provided, however, that the Company
shall not be required to pay for any expenses of any registration proceeding
begun pursuant to Section 2.2 if the registration request is subsequently
withdrawn, unless the Holders of a majority in interest of the Registrable
Securities agree to forfeit their right to one (1) of the demand registrations
permitted pursuant to this Section 2.2; and provided further that if the
withdrawal of the registration request results from either (a) intentional
actions by the Company outside the normal course of business, or (b) the
discovery of information about the Company that is not known at the time of the
Initiating


                                       6.
<PAGE>   10
Holders' request made pursuant to Section 2.2(a) that materially reduces the
feasibility of the registration proceeding, the Company shall be required to pay
expenses pursuant to this subparagraph (f) without the Holders forfeiting their
right to a demand registration and such registration shall not be deemed to have
been requested. All expenses incurred in connection with any subsequent
registration requested pursuant to this Section 2.2 shall be borne by the
Holders in proportion to the number of Registrable Securities owned by the
Holders included in the registration at the time it goes effective. A
registration request shall be deemed to be withdrawn and the Company shall have
no obligation with respect to any registration requested pursuant to this
Section 2.2 if by reason of withdrawal therefrom by a Holder of Registrable
Securities, the number of shares or aggregate anticipated offering price is less
than the amount needed to initially effectuate the Company's obligations
pursuant to this Section 2.2; provided, that the Holders shall not be deemed to
have forfeited their right to a demand registration and such registration shall
not be deemed to have been requested.

         2.3 PIGGYBACK REGISTRATIONS. The Company shall notify all Holders of
Registrable Securities in writing at least thirty (30) days prior to filing any
registration statement under the Securities Act for purposes of a public
offering of securities of the Company (including, but not limited to,
registration statements relating to secondary offerings of securities of the
Company and registration statements initiated by others, but excluding
registration statements relating to employee benefit plans and corporate
reorganizations) and will afford each such Holder an opportunity to include in
such registration statement all or part of such Registrable Securities held by
such Holder. Each Holder desiring to include in any such registration statement
all or any part of the Registrable Securities held by it shall, within twenty
(20) days after receipt of the above-described notice from the Company, so
notify the Company in writing. Such notice shall state the intended method of
disposition of the Registrable Securities by such Holder. If a Holder decides
not to include all of its Registrable Securities in any registration statement
thereafter filed by the Company, such Holder shall nevertheless continue to have
the right to include any Registrable Securities in any subsequent registration
statement or registration statements as may be filed by the Company with respect
to offerings of its securities, all upon the terms and conditions set forth
herein.

                  (a) UNDERWRITING. If the registration statement under which
the Company gives notice under this Section 2.3 is for an underwritten offering,
the Company shall so advise the Holders of Registrable Securities. In such
event, the right of any such Holder to be included in a registration pursuant to
this Section 3.3 shall be conditioned upon such Holder's participation in such
underwriting and the inclusion of such Holder's Registrable Securities in the
underwriting to the extent provided herein. All Holders proposing to distribute
their Registrable Securities through such underwriting shall enter into an
underwriting agreement in customary form with the underwriter or underwriters
selected for such underwriting. Notwithstanding any other provision of the
Agreement, if the underwriter determines in good faith that marketing factors
require a limitation of the number of shares to be underwritten, the number of
shares that may be included in the underwriting shall be allocated, first, to
the Company; and second, to the Holders on a pro rata basis based on the total
number of Registrable Securities held by the Holders. No such reduction shall
reduce the securities being offered by the Company for its own account to be
included in the registration and underwriting, except that in no event shall the
amount of securities of the selling Holders included in the


                                       7.
<PAGE>   11
registration be reduced below twenty percent (20%) of the total amount of
securities included in such registration, unless such offering is the Initial
Offering, in which event any or all of the Registrable Securities of the Holders
may be excluded in accordance with the immediately preceding sentence. For
purposes of the preceding concerning apportionment, for any selling shareholder
which is a holder of Registrable Securities and which is a partnership or
corporation, the partners, retired partners and shareholders of such holder, or
the estates and family members of any such partners and retired partners and any
trusts for the benefit of any of the foregoing persons shall be deemed to be a
single "selling shareholder", and any pro-rata reduction with respect to such
"selling shareholder" shall be based upon the aggregate amount of shares
carrying registration rights owned by all entities and individuals included in
such "selling shareholder", as defined in this sentence. If any Holder
disapproves of the terms of any such underwriting, he may elect to withdraw
therefrom by written notice to the Company and the underwriter, delivered at
least five (5) days prior to the effective date of the registration statement.
Any Registrable Securities excluded or withdrawn from such underwriting shall be
withdrawn from the registration.

                  (b) REGISTRATION EXPENSES. The Company shall bear all fees and
expenses incurred in connection with the first three registrations under this
Section 2.3 (excluding underwriters' discounts and commissions, which shall be
paid by the selling Holders pro rata), including without limitation all
registration, filing, qualification, printers' and accounting fees, fees and
disbursements of counsel to the Company, and the reasonable fees and
disbursements of one special counsel to the selling Holders. Subsequent
registrations under this Section 2.3 shall be borne by the Holders in proportion
to the number of Registrable Securities owned by the Holders included in such
registration at the time it goes effective.

         2.4 FORM S-3 REGISTRATION. In case the Company shall receive a written
request from the Holder of not less than thirty percent (30%) of the Registrable
Securities Then Outstanding that the Company effect a registration on Form S-3
and any related qualification or compliance with respect to all or a part of the
Registrable Securities owned by such Holders, the Company will:

                  (a) promptly give written notice of the proposed registration,
and any related qualification or compliance, to all other Holders of Registrable
Securities; and

                  (b) as soon as practicable, effect such registration and all
such qualifications and compliances as may be so requested and as would permit
or facilitate the sale and distribution of all or such portion of such Holders'
Registrable Securities as are specified in such request, together with all or
such portion of the Registrable Securities of any other Holders joining in such
request as are specified in a written request given within fifteen (15) days
after receipt of such written notice from the Company; provided, however, that
the Company shall not be obligated to effect any such registration,
qualification or compliance pursuant to this Section 2.4: (i) if Form S-3 is not
available for such offering by the Holders, (ii) if the Holders, together with
the holders of any other securities of the Company entitled to inclusion in such
registration, propose to sell Registrable Securities and such other securities
(if any) at an aggregate price to the public of less than $500,000, (iii) if the
Company shall furnish to the Holders a certificate signed by the President of
the Company stating that in the good faith


                                       8.
<PAGE>   12
judgment of the Board of Directors of the Company, it would be seriously
detrimental to the Company and its shareholders for such Form S-3 Registration
to be effected at such time, in which event the Company shall have the right to
defer the filing of the Form S-3 registration statement for a period of not more
than ninety (90) days after receipt of the request of the Holder or Holders
under this Section 2.4, provided that the Company shall not have the right to
make such deferral more than one time in any twelve month period, (iv) if the
Company has, within the twelve (12) month period preceding the date of such
request, already effected two (2) registrations on Form S-3 for the Holders
pursuant to this Section 2.4, or (v) in any particular jurisdiction in which the
Company would be required to qualify to do business or to execute a general
consent to service of process in effecting such registration, qualification or
compliance.

                  (c) Subject to the foregoing, the Company shall file a Form
S-3 registration statement covering the Registrable Securities and other
securities so requested to be registered as soon as practicable after receipt of
the request or requests of the Holders. All expenses incurred in connection with
any registration requested pursuant to this Section 2.4 shall be borne by the
Holders in proportion to the number of Registrable Securities owned by the
Holders included in such registration at the time it goes effective.
Registrations pursuant to this Section 2.4 do not reduce the number of
registrations to which Holders are entitled pursuant to Section 2.2 or 2.3
hereof.

         2.5 OBLIGATIONS OF THE COMPANY. Whenever required to effect the
registration of any Registrable Securities pursuant to this Agreement, the
Company shall, as expeditiously as reasonably possible:

                  (a) Prepare and file with the SEC a registration statement
with respect to such Registrable Securities and use its best efforts to cause
such registration statement to become effective, and, upon the request of the
Holders of a majority of the Registrable Securities registered thereunder, keep
such registration statement effective for up to one hundred twenty (120) days.

                  (b) Prepare and file with the SEC such amendments and
supplements to such registration statement and the prospectus used in connection
with such registration statement as may be necessary to comply with the
provisions of the Securities Act with respect to the disposition of all
securities covered by such registration statement.

                  (c) Furnish to the Holders such number of copies of a
prospectus, including a preliminary prospectus, in conformity with the
requirements of the Securities Act, and such other documents as they may
reasonably request in order to facilitate the disposition of Registrable
Securities owned by them.

                  (d) Use its best efforts to register and qualify the
securities covered by such registration statement under such other securities or
Blue Sky laws of such jurisdictions as shall be reasonably requested by the
Holders, provided that the Company shall not be required in connection therewith
or as a condition thereto to qualify to do business or to file a general consent
to service of process in any such states or jurisdictions.


                                       9.
<PAGE>   13
                  (e) In the event of any underwritten public offering, enter
into and perform its obligations under an underwriting agreement, in usual and
customary form, with the managing underwriter(s) of such offering. Each Holder
participating in such underwriting will also enter into and perform its
obligations under such an agreement.

                  (f) Notify each Holder of Registrable Securities covered by
such registration statement at any time when a prospectus relating thereto is
required to be delivered under the Securities Act of the happening of any event
as a result of which the prospectus included in such registration statement, as
then in effect, includes an untrue statement of a material fact or omits to
state a material fact required to be stated thereon or necessary to make the
statements therein not misleading in the light of the circumstances then
existing.

                  (g) Furnish, at the request of any Holder requesting
registration of Registrable Securities, on the date that such Registrable
Securities are delivered to the underwriters for sale, if such securities are
being sold through underwriters, or, if such securities are not being sold
through underwriters, on the date that the registration statement with respect
to such securities becomes effective, (i) an opinion, dated as of such date, of
the counsel representing the Company for the purposes of such registration, in
form and substance as is customarily given to underwriters in an underwritten
public offering and reasonably satisfactory to a majority in interest of the
Holders requesting registration, addressed to the underwriters, if any, and to
the Holders requesting registration of Registrable Securities and (ii) a letter
dated as of such date, from the independent certified public accountants of the
Company, in form and substance as is customarily given by independent certified
public accountants to underwriters in an underwritten public offering and
reasonably satisfactory to a majority in interest of the Holders requesting
registration, addressed to the underwriters, if any, and to the Holders
requesting registration of Registrable Securities.

         2.6 TERMINATION OF REGISTRATION RIGHTS. The registration rights granted
under Section 2.2 and Section 2.3 shall terminate and be of no further force and
effect on the dates five (5) years and ten (10) years, respectively, following
the Company's Initial Offering.

         2.7 FURNISH INFORMATION. It shall be a condition precedent to the
obligations of the Company to take any action pursuant to Sections 2.2, 2.3 or
2.4 that the selling Holders shall furnish to the Company such information
regarding themselves, the Registrable Securities held by them, and the intended
method of disposition of such securities as shall be required to effect the
registration of their Registrable Securities.

         2.8 DELAY OF REGISTRATION. No Holder shall have any right to obtain or
seek an injunction restraining or otherwise delaying any such registration as
the result of any controversy that might arise with respect to the
interpretation or implementation of this Article II.

         2.9 INDEMNIFICATION.  In the event any Registrable Securities are
included in a registration statement under Section 2.2, 2.3 or 2.4:

                  (a) To the extent permitted by law, the Company will indemnify
and hold harmless each Holder, the partners, officers and directors of each
Holder, any underwriter (as


                                       10.
<PAGE>   14
defined in the Securities Act) for such Holder and each person, if any, who
controls such Holder or underwriter within the meaning of the Securities Act or
the Securities Exchange Act of 1934, as amended, (the "1934 Act"), against any
losses, claims, damages, or liabilities (joint or several) to which they may
become subject under the Securities Act, the 1934 Act or other federal or state
law, insofar as such losses, claims, damages, or liabilities (or actions in
respect thereof) arise out of or are based upon any of the following statements,
omissions or violations (collectively a "Violation") by the Company: (i) any
untrue statement or alleged untrue statement of a material fact contained in
such registration statement, including any preliminary prospectus or final
prospectus contained thereon or any amendments or supplements thereto, (ii) the
omission or alleged omission to state therein a material fact required to be
stated therein, or necessary to make the statements therein not misleading, or
(iii) any violation or alleged violation by the Company of the Securities Act,
the 1934 Act, any state securities law or any rule or regulation promulgated
under the Securities Act, the 1934 Act or any state securities law in connection
with the offering covered by such registration statement; and the Company will
reimburse as incurred, each such Holder, partner, officer or director,
underwriter or controlling person for any legal or other expenses reasonably
incurred by them in connection with investigating or defending any such loss,
claim, damage, liability or action; provided, however, that the indemnity
agreement contained in this Section 2.9(a) shall not apply to amounts paid in
settlement of any such loss, claim, damage, liability or action if such
settlement is effected without the consent of the Company (which consent shall
not be unreasonably withheld), nor shall the Company be liable in any such case
for any such loss, claim, damage, liability or action to the extent that it
arises out of or is based upon a Violation which occurs in reliance upon and in
conformity with written information furnished expressly for use in connection
with such registration by such Holder, partner, officer, director, underwriter
or controlling person or such Holder.

                  (b) To the extent permitted by law, each selling Holder will
indemnify and hold harmless the Company, each of its directors, each of its
officers who have signed the registration statement, each person, if any, who
controls the Company within the meaning of the Securities Act, any underwriter
and any other Holder selling securities under such registration statement or any
of such other Holder's partners, directors or officers or any person who
controls such Holder, against any losses, claims, damages or liabilities (joint
or several) to which the Company or any such director, officer, controlling
person, underwriter or other such Holder, or partner, director, officer or
controlling person of such other Holder may become subject under the Securities
Act, the 1934 Act or other federal or state law, insofar as such losses, claims,
damages or liabilities (or actions in respect thereto) arise out of or are based
upon any Violation, in each case to the extent (and only to the extent) that
such Violation occurs in reliance upon and in conformity with written
information furnished by such Holder expressly for use in connection with such
registration; and each such Holder will reimburse, as incurred, any legal or
other expenses reasonably incurred by the Company or any such director, officer,
controlling person, underwriter or other Holder, or partner, officer, director
or controlling person of such other Holder in connection with investigating or
defending any such loss, claim, damage, liability or action if it is judicially
determined that there was such a Violation; provided, however, that the
indemnity agreement contained in this Section 2.9(b) shall not apply to amounts
paid in settlement of any such loss, claim, damage, liability or action if such
settlement is effected without the consent of the Holder, which consent shall
not be unreasonably withheld;


                                       11.
<PAGE>   15
provided further, that in no event shall any indemnity under this Section 2.9(b)
exceed the gross proceeds from the offering received by such Holder.

                  (c) Promptly after receipt by an indemnified party under this
Section 2.9 of notice of the commencement of any action (including any
governmental action), such indemnified party will, if a claim in respect thereof
is to be made against any indemnifying party under this Section 2.9, deliver to
the indemnifying party a written notice of the commencement thereof and the
indemnifying party shall have the right to participate in, and, to the extent
the indemnifying party so desires, jointly with any other indemnifying party
similarly noticed, to assume the defense thereof with counsel mutually
satisfactory to the parties; provided, however, that an indemnified party shall
have the right to retain its own counsel, with the fees and expenses to be paid
by the indemnified party, if representation of such indemnified party by the
counsel retained by the indemnifying party would be inappropriate due to actual
or potential differing interests between such indemnified party and any other
party represented by such counsel in such proceeding. The failure to deliver
written notice to the indemnifying party within a reasonable time of the
commencement of any such action, if materially prejudicial to its ability to
defend such action, shall relieve such indemnifying party of any liability to
the indemnified party under this Section 2.9, but the omission so to deliver
written notice to the indemnifying party will not relieve otherwise than under
this Section 2.9.

                  (d) If the indemnification provided for in this Section 2.9 is
held by a court of competent jurisdiction to be unavailable to an indemnified
party with respect to any losses, claims, damages or liabilities referred to
herein, the indemnifying party, in lieu of indemnifying such indemnified party
thereunder, shall to the extent permitted by applicable law contribute to the
amount paid or payable by such indemnified party as a result of such loss,
claim, damage or liability in such proportion as is appropriate to reflect the
relative fault of the indemnifying party on the one hand and of the indemnified
party on the other in connection with Violation(s) that resulted in such loss,
claim, damage or liability, as well as any other relevant equitable
considerations. The relative fault of the indemnifying party and of the
indemnified party shall be whether the untrue or alleged untrue statement of a
material fact supplied by the indemnifying party or by the indemnified party and
the parties' relative intent, knowledge, access to information and opportunity
to correct or prevent such statement or omission.

                  (e) The obligations of the Company and Holders under this
Section 2.9 shall survive the completion of any offering of Registrable
Securities in a registration statement, and otherwise.

         2.10 ASSIGNMENT OF REGISTRATION RIGHTS. Except as otherwise provided
herein, the rights contained in this Article II may be assigned or otherwise
conveyed to a transferee or assignee of Registrable Securities, who shall be
considered a "Holder" for purposes of this Article II, provided that (i) such
transfer is effected in accordance with applicable federal and state securities
laws, (ii) such transferee or assignee becomes a party to this Agreement or
agrees in writing to be subject to the terms hereof to the same extent as if he
were an original purchaser hereunder and (iii) such transferee or assignee (A)
is a wholly owned subsidiary or constituent partner (including limited partners)
or affiliate of the transferring Holder, or (B) acquires at least ten thousand
(10,000) shares (as presently constituted) of the Registrable Securities, or


                                       12.
<PAGE>   16
(C) acquires all of the shares then held by the transferring Holder and,
provided further, that the Company is given written notice by such Holder at the
time of or within a reasonable time after said transfer, stating the name and
address of said transferee or assignee and identifying the securities with
respect to which such registration rights are being assigned.

         For the purposes of determining the number of shares of Registrable
Securities held by a transferee or assignee, the holdings of transferees and
assignees of a partnership (including spouses and ancestors, lineal descendants
and siblings of such partners or spouses who acquire Registrable Securities by
gift, will or intestate succession) shall be aggregated together and with the
partnership; provided that all assignees and transferees who would not qualify
individually for assignment of registration rights shall have a single
attorney-in-fact for the purpose of exercising any rights, receiving notices or
taking any action under this Article II.

         2.11 "MARKET STAND-OFF" AGREEMENT. Each Holder hereby agrees that,
during the period or duration specified by the Company and any underwriter of
common stock or other securities of the Company following the effective date of
a registration statement of the Company filed under the Act, it shall not, to
the extent requested by the Company and such underwriter, directly or
indirectly, sell, offer to sell, contract to sell (including, without
limitation, any short sale), grant any option to purchase or otherwise transfer
or dispose of (other than to donees who agree to be similarly bound) any
securities of the Company held by it at any time during such period except
common stock included in such registration; provided, however, that:

                  (a) such agreement shall be applicable only to the first such
registration statement of the Company which covers common stock (or other
securities) to be sold on its behalf to the public in an underwritten offering;

                  (b)      such period shall not exceed 180 days; and

                  (c) all officers and directors of the Company and all other
persons with registration rights (whether or not pursuant to this Agreement)
enter into similar agreements.

         In order to enforce the foregoing covenant, the Company may impose
stop-transfer instructions with respect to the Registrable Securities of each
investor (and the shares or securities of every other person subject to the
foregoing restriction) until the end of such period.

         2.12 AMENDMENT OF REGISTRATION RIGHTS. Any provision of this Article II
may be amended, and the observance thereof may be waived (either generally or in
a particular instance and either retroactively or prospectively), only with the
written consent of the Company and the Holders of not less than two-thirds (2/3)
in interest of the Registrable Securities. Any amendment or waiver effected in
accordance with this Section 2.12 shall be binding upon each Holder and the
Company. By acceptance of any benefits under this Article II, Holders of
Registrable Securities hereby agree to be bound by the provisions hereunder.

         2.13 LIMITATION ON SUBSEQUENT REGISTRATION RIGHTS.  After the date of 
this Agreement, the Company shall not, without the prior written consent of the
Holders of not less than two-thirds (2/3) in interest of the Registrable
Securities, enter into any agreement with any


                                       13.
<PAGE>   17
holder or prospective holder of any securities of the Company that would permit
such holder to require the Company to register any securities held by such
holder if the granting of such registration rights has been authorized by a vote
of at least four members of the Board of Directors; provided, however, that the
Company may obligate itself to register securities issued in connection with
credit or leasing transactions without the prior written consent of the Holders.

                                      III.

                            COVENANTS OF THE COMPANY

         3.1      BASIC FINANCIAL INFORMATION AND REPORTING.

                  (a) The Company will maintain true books and records of
account in which full and correct entries will be made of all its business
transactions pursuant to a system of accounting established and administered in
accordance with generally accepted accounting principles consistently applied,
and will set aside on its books all such proper accruals and reserves as shall
be required under generally accepted accounting principles consistently applied.

                  (b) So long as a Holder shall own shares of Series A Stock,
Series B Stock, Series C Stock, Series D Stock and Series E Stock with an
aggregate original issuance price of $500,000, the Company shall: (i) as soon as
practicable after the end of each fiscal year of the Company, and in any event
within 90 days thereafter, furnish such Holder a consolidated balance sheet of
the Company, as of the end of such fiscal year, and a consolidated statement of
income and a consolidated statement of cash flows of the Company, for such year,
all prepared in accordance with generally accepted accounting principles
("GAAP") and setting forth in each case in comparative form the figures for the
previous fiscal year, all in reasonable detail (such balance sheet and statement
of income shall be accompanied by a report and opinion thereon by independent
certified public accountants of national standing selected by the Company's
Board of Directors); (ii) as soon as practicable after the end of the first,
second and third quarterly accounting periods in each fiscal year of the
Company, and in any event within 30 days thereafter, furnish such Holder a
consolidated balance sheet of the Company as of the end of each such quarterly
period, and a statement of income and a consolidated statement of cash flows of
the Company for such period and for the current fiscal year to date, prepared in
accordance with GAAP, with the exception that no notes need be attached to such
statements and year-end audit adjustments may not have been made; and (iii)
furnish at least thirty (30) days prior to the beginning of each fiscal year an
annual budget and operating plans for such fiscal year; and (iv) within thirty
(30) days after the end of each month, an unaudited balance sheet and a
statement of operations, prepared in accordance with GAAP, which also set forth
applicable budget figures and variances from budget, and within a reasonable
time after a request therefor, all reports relating to the Company that the
Board of Directors of the Company deems reasonable to provide.

         3.2      INSPECTION RIGHTS.  So long as a Holder shall own shares of 
Series A Stock, Series B Stock, Series C Stock, Series D Stock and Series E
Stock with an aggregate original issuance price of $500,000, such Holder shall
have the right to visit and inspect any of the


                                       14.
<PAGE>   18
properties of the Company or any of its subsidiaries, and to discuss the
affairs, finances and accounts of the Company or any of its subsidiaries with
its officers, all at such reasonable times and as often as may be reasonably
requested; provided, however, that the Company shall not be obligated pursuant
to this Section 3.2 to provide access to any information which it reasonably
considers to be a trade secret or similar confidential information.

         3.3 CONFIDENTIALITY OF RECORDS. Each Holder agrees to use its best
efforts to insure that its authorized representatives use, the same degree of
care as such Holder uses to protect its own confidential information to keep
confidential any information furnished to it which the Company identifies as
being confidential or proprietary (so long as such information is not in the
public domain), except that such Holder may disclose such proprietary or
confidential information (excluding technical information but including
financial and other general business information) with the prior written consent
of the Company. Notwithstanding the foregoing, the prior written consent of the
Company shall not be required if such non-technical proprietary or confidential
information is to be disclosed to a Holder's counsel or accountant, or to an
officer, director, parent, subsidiary or general or limited partner of a Holder,
or to employees of, or consultants to, a Holder on a "need to know" basis,
provided that the Holder shall inform the recipient of the confidential nature
of such information.

         3.4 INSURANCE. The Company will maintain "key-person" life insurance on
the lives of George D. Cimino, Laurence Corash, John E. Hearst, Stephen T.
Isaacs and Lily Lin, in the amount of $1,000,000 for each person, with the
Company named as beneficiary. The Company will maintain insurance coverage
against loss or damage to the Company's properties and business in the amounts
and on the terms and conditions as Board of Directors shall reasonably
determine.

         3.5 PROPRIETARY INFORMATION AGREEMENTS.  The Company shall enter into 
agreements substantially in the form of Exhibit A attached hereto, in a timely
manner, with each of its technical  employees and consultants.

         3.6 EMPLOYEE AGREEMENTS. All current and future employees, officers and
consultants of the Company who shall, subsequent to the Closing Date, purchase
or receive options to purchase shares of the Company's Common Stock shall
(unless the Board of Directors shall direct otherwise) be required to execute
stock purchase or option agreements providing for vesting of shares no less
restrictive than as follows: one-eighth of the total number of shares subject to
such an agreement six months after the date of employment or commencement of
consulting relationship and one forty-eighth of the total number of shares
subject to such an agreement each month thereafter. Upon the termination of an
employee, officer or consultant, with or without cause, the Company or its
assignee will (unless the Board of Directors shall direct otherwise) have the
option to repurchase the unvested portion of such shares held by the employee,
officer or consultant at cost. Such stock purchase or option agreements shall
(unless the Board of Directors shall direct otherwise) also provide for (i) no
transfers prior to vesting, (ii) a right of first refusal on any vested shares
terminating not prior to the initial public offering of the Company's securities
and (iii) a "lock-up" provision of at least 180 days after the initial public
offering of the Company's securities.


                                       15.
<PAGE>   19
         3.7 OBSERVER RIGHTS. If the Holders do not have a member on the
Company's Board of Directors for whatsoever reason, the Company shall invite at
least one representative of the Holders (chosen by written consent of a majority
in interest of the Holders) to attend all meetings of its Board of Directors in
a nonvoting observer capacity and, in this respect, shall give such
representative copies of all notices, minutes, consents, and other materials
that it provides to its directors; provided, however, that such representative
shall agree to hold in confidence and trust and to act in a fiduciary manner
with respect to all information so provided; and, provided further, that the
Company reserves the right to withhold any information and to exclude such
representative from any meeting or portion thereof if access to such information
or attendance at such meeting could adversely affect the attorney-client
privilege between the Company and its counsel.

         3.8 TERMINATION OF COVENANTS.  The covenants contained in this Article
III hereof shall expire and terminate upon the consummation of the Initial
Offering.

                                       IV.

                             RIGHTS OF FIRST REFUSAL

         4.1 SUBSEQUENT OFFERINGS.

                  (a) So long as the Baxter Agreement is in effect and Baxter is
not in material breach of its obligations thereunder, Baxter shall have a right
of first refusal to purchase up to nineteen and nine-tenths percent (19.9%) of
all Equity Securities, as defined below, that the Company may, from time to
time, propose to sell and issue after the date of this Agreement, other than the
Equity Securities excluded by Section 4.6 below.

                  (b) Each Holder other than Baxter shall have a right of first
refusal to purchase its pro rata share of all Equity Securities remaining, if
any, after taking into account Baxter's exercise of its rights of first refusal
set forth in Sections 4.1(a) and 4.2(a) hereof. Each Holder's pro rata share of
Equity Securities shall be defined as the ratio of the number of Registrable
Securities with respect to which such Holder is deemed to be holder immediately
prior to the issuance of such Equity Securities to the total number of shares of
Common Stock of the Company outstanding or issuable upon conversion of
outstanding Equity Securities (excluding any of the same held by Baxter).

                  (c) The term "Equity Securities" shall mean (i) any capital
stock of the Company, (ii) any security convertible, with or without
consideration, into any stock or similar security, (iii) any option, warrant or
right to subscribe to or purchase any capital stock.

         4.2 EXERCISE OF RIGHTS.

                  (a) If the Company proposes to issue any Equity Securities, it
shall give Baxter written notice of its intention, describing the Equity
Securities, the price, and the terms and conditions upon which the Company
proposes to issue the same. Baxter shall have twenty (20)


                                       16.
<PAGE>   20
days from the giving of such notice (the "Baxter Notice Period") to agree to
purchase up to the nineteen and nine-tenths percent (19.9%) of such Equity
Securities for the price and upon the terms and conditions specified in the
notice by giving written notice to the Company and stating therein the quantity
of such Equity Securities to be purchased.

                  (b) As soon as practically possible after the end of the
Baxter Notice Period, the Company shall give the Holders other than Baxter
written notice of its intention to issue those Equity Securities remaining after
Baxter's exercise of its right of first refusal, which notice shall describe
such Equity Securities, the price, and the conditions upon which the Company
proposes to issue the same. Each Holder other than Baxter shall have twenty (20)
days from the giving of such notice to agree to purchase its pro rata share of
Equity Securities for the price and upon the terms and conditions specified in
the notice by giving written notice to the Company and stating therein the
quantity of such Equity Securities to be purchased. If any such Holder does not
elect to purchase its full pro rata share of such Equity Securities, the Company
shall promptly inform each Holder other than Baxter which purchases all of the
Equity Securities available to it ("Fully Exercising Holder") of any other
Holder's failure to do likewise. During the ten-day period commencing after the
mailing of such information, each Fully Exercising Holder shall be entitled to
purchase its pro rata share of Equity Securities offered by the Company but
unsold. Duly Registrable Securities held by Fully Exercising Holders shall be
considered in determining each Fully Exercising Holder's pro rata share.

         4.3 ISSUANCE OF EQUITY SECURITIES TO OTHER PERSONS. The Company shall
have sixty (60) days after the end of the Baxter Notice Period to sell those
Equity Securities offered by the Company but not sold at a price and upon terms
and conditions no more favorable to the purchasers thereof than those specified
in the Company's notices to the Holders pursuant to Section 4.2 hereof. If the
Company has not sold the Equity Securities within such sixty (60) days, the
Company shall not thereafter issue or sell any Equity Securities, without first
offering such securities to the Holders provided above.

         4.4 TERMINATION OF RIGHTS OF FIRST REFUSAL.  The rights of first 
refusal established by this Article IV shall terminate immediately prior to the
consummation of the Initial Offering.

         4.5 TRANSFER OF RIGHTS OF FIRST REFUSAL.

                  (a)      The rights of first refusal of Baxter under this 
Article IV may not be transferred.

                  (b)      The rights of first refusal of each Holders under 
this Article IV may be transferred to a party to whom a transfer or assignment
of registration rights may be made pursuant to Section 2.10 hereof and only if
made concurrently with the transfer of such registration rights to such party.

         4.6 EXCLUDED SECURITIES.  The rights of first refusal established by 
this Article IV shall have no application to any of the following Equity
Securities:


                                       17.
<PAGE>   21
                  (a) shares of Common Stock (and/or options, warrants or other
Common Stock purchase rights issued pursuant to such options, warrants or other
rights) issued or to be issued to employees, officers or directors of, or
consultants or advisors to the Company or any subsidiary, pursuant to stock
purchase or stock option plans or other arrangements;

                  (b) stock issued pursuant to any rights or agreements
outstanding as of the date of that certain Series E Stock Purchase Agreement by
and between the Company and Baxter entered into as of April 1, 1996, including,
without limitation, convertible securities, options and warrants; and stock
issued pursuant to any such rights or agreements granted after the date of such
agreement, provided that the rights of first refusal established by this Article
IV applied with respect to the initial sale or grant by the Company of such
rights or agreements;

                  (c) any Equity Securities issued for consideration other than
cash pursuant to a merger, consolidation, acquisition or similar business
combination;

                  (d) any Equity Securities that are issued by the Company as 
part of an Initial Offering;

                  (e) shares of Common Stock issued in connection with any stock
split, stock dividend or recapitalization by the Company;

                  (f) shares of Common Stock issued pursuant to any leasing or 
credit arrangement for other than primarily equity financing purposes; and

                  (g) Equity Securities sold to Baxter pursuant to Sections 4.1 
or 4.2 of the Baxter Agreement.


                                       V.

                                  MISCELLANEOUS

         5.1 GOVERNING LAW.  This Agreement shall be governed in all respects by
the laws of the State of California.

         5.2 SURVIVAL. The representations, warranties, covenants, and
agreements made herein shall survive any investigation made by any Holder and
the closing of the transactions contemplated hereby. All statements as to
factual matters contained in any certificate or other instrument delivered by or
on behalf of the Company pursuant hereto in connection with the transactions
contemplated hereby shall be deemed to be representations and warranties by the
Company hereunder solely as of the date of such certificate or instrument.

         5.3 SUCCESSORS AND ASSIGNS. Except as otherwise expressly provided
herein, the provisions hereof shall inure to the benefit of, and be binding
upon, the successors, assigns, heirs, executors, and administrators of the
parties hereto and shall inure to the benefit of and be enforceable by each
person who shall be a holder of Registrable Securities from time to time;


                                       18.
<PAGE>   22
provided, however, that prior to the receipt by the Company of adequate written
notice of the transfer of any Registrable Securities specifying the full name
and address of the transferee, the Company may deem and treat the person listed
as the holder of such shares in its records as the absolute owner and holder of
such shares for all purposes, including the payment of dividends or any
redemption price.

         5.4 SEPARABILITY. In case any provision of the Agreement shall be
invalid, illegal, or unenforceable, the validity, legality, and enforceability
of the remaining provisions shall not in any way be affected or impaired
thereby.

         5.5 AMENDMENT AND WAIVER.

                  (a) This Agreement may be amended or modified only upon the
written consent of the Holders of not less than a two-thirds (2/3) in interest
of the Registrable Securities. Notwithstanding the foregoing, so long as Baxter
is not in default of the Baxter Agreement or this Agreement and continues to
hold at least ninety percent (90%) of the stock that it has purchased pursuant
to the Baxter Agreement and this Agreement, through the date of the proposed
amendment or modification of this Agreement, Sections 4.1(a) and 4.2(a) of this
Agreement may be amended or modified only upon the written consent of Baxter.

                  (b) The obligations of the Company and the rights of the
Holders under this Agreement may be waived only with the written consent of the
Holders of not less than a two-thirds (2/3) in interest of the Registrable
Securities.

                  (c) Except to the extent provided in this Section 5.5, neither
this Agreement nor any provision hereof may be changed, waived, discharged, or
terminated, except by a statement in writing signed by the party against which
enforcement of the change, waiver, discharge, or termination is sought.

         5.6 DELAYS OR OMISSIONS. It is agreed that no delay or omission to
exercise any right, power, or remedy accruing to any Holder, upon any breach,
default or noncompliance of the Company under this Agreement shall impair any
such right, power, or remedy, nor shall it be construed to be a waiver of any
such breach, default or noncompliance, or any acquiescence therein, or of or in
any similar breach, default or noncompliance thereafter occurring. It is further
agreed that any waiver, permit, consent, or approval of any kind or character on
any Holder's part of any breach, default or noncompliance under the Agreement or
any waiver on such Holder's part of any provisions or conditions of this
Agreement must be in writing and shall be effective only to the extent
specifically set forth in such writing. All remedies, either under this
Agreement, by law, or otherwise afforded to Holders, shall be cumulative and not
alternative.

         5.7 NOTICES, ETC. All notices and other communications required or
permitted hereunder shall be in writing and shall be sent by registered or
certified mail, return receipt requested, postage prepaid, and, if to an address
outside the United States of America, by telex or facsimile transmitted
substantially concurrently with the mailing of such written notice, addressed:
(a) if to a Holder, at such Holder's address as set forth on the Company's
records,


                                      19.
<PAGE>   23
or at such other address as such Holder shall have furnished to the Company in
writing or (b) if to the Company, at its address as set forth at the end of this
Agreement, or at such other address as the Company shall have furnished to the
Holders in writing.

         5.8      ATTORNEYS' FEES.  If legal action is brought to enforce or 
interpret this Agreement, the prevailing party shall be entitled to recover its
reasonable attorneys' fees and legal costs in connection therewith.

         5.9      TITLES AND SUBTITLES.  The titles of the paragraphs and 
subparagraphs of this Agreement are for convenience of reference only and are
not to be considered in construing this Agreement.

         5.10     COUNTERPARTS.  This Agreement may be executed in any number of
counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.


                                       20.
<PAGE>   24
         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date set forth in the first paragraph hereof.

COMPANY:

STERITECH, INC.
2525 Stanwell Drive, Suite 300
Concord, CA  94520

By:   /s/ Stephen T. Isaacs
      -------------------------
Title:          President
      -------------------------

INVESTORS:

MR. VINCENT E. WRIGHT

By:   /s/ Vincent Wright
      -------------------------
Title:
      -------------------------
                (Title)

MR. CLAUDE L. GANZ

By:   /s/ Claude L. Ganz
      -------------------------
                (Title)

DOWN, ANN M., TRUSTEE FBO ANN M. DOWN REV TRUST U/A/D 09/22/95

By:   /s/ Ann M. Down
      -------------------------
                Trustee
      -------------------------
                (Title)


                                       21.
<PAGE>   25
MR. JAMES D. WOLFENSOHN

By:   /s/ James D. Wolfensohn
      -------------------------

      -------------------------          
               (Title)

MR. GEORGE D. CIMINO

By:  /s/ George D. Cimino
      -------------------------

      -------------------------  
                (Title)

KURT A. LATTA PROFIT SHARING PLAN

By:   /s/ Kurt A. Latta
      -------------------------
                Trustee
      -------------------------
                (Title)

MR. KURT A. LATTA TRUSTEE OF THE KURT A. LATTA PENSION PLAN

By:   /s/ Kurt A. Latta
      -------------------------
                Trustee
      -------------------------
                (Title)

MR. LATTA, KURT A., TTEE (FOR RACHEL LATTA) OF THE 1990 LATTA IRREVOCABLE
TRUST, SUBTRUST FOR RACHEL LATTA

By:   /s/ Kurt A. Latta
      -------------------------
                Trustee
      -------------------------
                (Title)


                                       22.
<PAGE>   26
MR. LATTA, KURT A., TTEE (FOR ANTHONY LATTA) OF THE 1990 LATTA IRREVOCABLE
TRUST, SUBTRUST FOR ANTHONY LATTA

By:   /s/ Kurt A. Latta
      -------------------------
                Trustee
      -------------------------
                (Title)

MR. LATTA, KURT A., TTEE (FOR ALEXANDRA LATTA) OF THE 1990 LATTA IRREVOCABLE
TRUST, SUBTRUST FOR ALEXANDRA LATTA

By:   /s/ Kurt A. Latta
      -------------------------
                Trustee
      -------------------------
                (Title)

MR. LATTA, KURT A., TTEE OF THE 1990 FAMILY TRUST

By:   /s/ Kurt A. Latta
      -------------------------
                Trustee
      -------------------------
                (Title)

KING, ROBERT ELIOT, DOROTHY JONES KING, TRUSTEES OF THE KING LIVING TRUST
U/A/D JUNE 19, 1989

By:   /s/ Robert Eliot King
      -------------------------
By:   /s/ Dorothy Jones King
      -------------------------
                Trustees
      -------------------------
                (Title)


                                       23.
<PAGE>   27
SAN FRANCISCO INTERNATIONAL INVESTORS

By:   /s/ Robert E. King
      -------------------------
           Managing Partner
      -------------------------
                (Title)

THE R.E.K. PROFIT SHARING PLAN

By:   /s/ Robert E. King
      -------------------------
                Trustee
      -------------------------
                (Title)

KING, ROBERT ELIOT, TRUSTEE UNDER THE TRUST OF THE R.E.K. PROFIT SHARING PLAN

By:   /s/ Robert E. King
      -------------------------
                Trustee
      -------------------------
                (Title)

DONALD L. LUCAS, TTEE DONALD L. LUCAS PROFIT SHARING TRUST DATED 1/1/87

By:   /s/ Donald L. Lucas
      -------------------------
           Successor Trustee
      -------------------------
                (Title)

RICHARD M. LUCAS CANCER FOUNDATION

By:   /s/ Donald L. Lucas
      -------------------------
        Chairman of the Board
      -------------------------
                (Title)


                                       24.
<PAGE>   28
DONALD L. LUCAS, TTEE, DONALD L. LUCAS & LYGIA S. LUCAS TRUST AGREEMENT
DATED 12/3/84

By:   /s/ Donald L. Lucas
      -------------------------
                Trustee
      -------------------------
                (Title)

CAROL P. PALKOVIC

By:   /s/ Carol P. Palkovic
      -------------------------

      -------------------------
                (Title)

SAND HILL FINANCIAL COMPANY

By:   /s/ Donald L. Lucas
      -------------------------
            General Partner
      -------------------------
                (Title)

ST. MARY'S COLLEGE

By:   /s/ Raymond J. White
      -------------------------
       Chief Financial Officer
      -------------------------
                (Title)

MR. CARL HANSON

By:   /s/ Carl Hanson
      -------------------------

      -------------------------
                (Title)

                                       25.
<PAGE>   29
THE TRUSTEES OF THE WALLACE R. HAWLEY AND ALEXANDRA HAWLEY REVOCABLE
TRUST, U/A/D 7/30/92

By:   /s/ Wallace R. Hawley
      -------------------------
                Trustee
      -------------------------
                (Title)

MR. ROBERT J. OSTER TRUSTEE OF THE NIKLAS OSTERSMITH 1995 IRREVOCABLE TRUST,
DATED APRIL 16, 1995

By:   /s/ Robert J. Oster
      -------------------------
                Trustee
      -------------------------
                (Title)

ROBERT J. & MARION E. OSTER, TTEES OSTER FAMILY REVOCABLE TRUST, DTD 10/5/76

By:   /s/ Robert J. Oster
      -------------------------
                Trustee
      -------------------------
                (Title)

MARK & SUZANNE OSTERSMITH

By:   /s/ Robert Ostersmith
      -------------------------
          Power of Attorney
      -------------------------
                (Title)

MR. ROY KIRKORIAN

By:   /s/ Roy Kirkorian
      -------------------------

      -------------------------
                (Title)


                                       26.
<PAGE>   30
A. CRAWFORD COOLEY

By:   /s/ A. Crawford Cooley
      -------------------------------

      -------------------------------
                (Title)

FRANK C. HERRINGER & MARYELLEN CATTANI HERRINGER

By:   /s/ Frank C. Herringer
      -------------------------------

By:   /s/ Maryellen Cattani Herringer
      -------------------------------

      -------------------------------
                (Title)

ERTOLA, ALEXANDRA LUCAS, C/F FOR JOHN PATRICK ERTOLA UTMA CA 21

By:   /s/ Alexandra Ertola
      -------------------------------
              Custodian
      -------------------------------
                (Title)

ERTOLA, ALEXANDRA LUCAS, C/F FOR JOSEPH LUCAS ERTOLA UTMA CA 21

By:   /s/ Alexandra Ertola
      -------------------------------
                Custodian
      -------------------------------
                (Title)

ERTOLA, ALEXANDRA LUCAS, C/F FOR NICHOLAS ALEXANDER ERTOLA UTMA CA 21

By:   /s/ Alexandra Ertola
      -------------------------------
                Custodian
      -------------------------------
                (Title)


                                       27.
<PAGE>   31
QUEST VENTURES INTERNATIONAL

By: /s/ Lucien Ruby
    ------------------------------------------
    General Partner of the General Partnership
    ------------------------------------------
                      (Title)

QUEST VENTURES II

By: /s/ Lucien Ruby
    ------------------------------------------
    General Partner of the General Partnership
    ------------------------------------------
                      (Title)

JOHN W. LUCAS, CO-TTEE LUCAS FAMILY TRUST, DTD 6/4/80

By: /s/ John W. Lucas
    ------------------------------------------
                    Co-Trustee
    ------------------------------------------
                      (Title)

GERALD C. DOWN

By: /s/ Gerald C. Down
    ------------------------------------------

    ------------------------------------------
                      (Title)

MR. MORTON L. TOPFER

By: /s/ Morton L. Topfer
    ------------------------------------------

    ------------------------------------------
                      (Title)


                                       28.
<PAGE>   32
MR. ROBERT DAVID SPRENG

By:/s/ Robert David Spreng
   --------------------------------

   --------------------------------
               (Title)

DR. SCOTT MURPHY

By:/s/ Scott Murphy
   --------------------------------

   --------------------------------
               (Title)

JOHN W. AND MARY G. LUCAS, CO-TTEE LUCAS TRUST A - UWO LEO J. LUCAS

By:/s/ John W. Lucas
   --------------------------------
              Co-Trustee
   --------------------------------
               (Title)

DAIN BOSWORTH, INC., CUSTODIAN FBO YUVAL ALMOG SEP.-IRA IFG OPERATIONS
GROUP/IRA DEPT.

By:/s/ P. H. Colbert
   --------------------------------
         First Vice President
   --------------------------------
               (Title)

JOSEPH B. COSTELLO AND MARGARET M. COSTELLO, TTEES OF THE COSTELLO FAMILY
TRUST DTD 10/21/92

By:/s/ Joseph B. Costello
   --------------------------------

   --------------------------------
               (Title)


                                       29.
<PAGE>   33
MR. LAURENCE CORASH

By:/s/ Laurence Corash
   --------------------------------

   --------------------------------
                (Title)

MR. DAVID KOEHLER

By:/s/ David Koehler
   --------------------------------

   --------------------------------
                (Title)

VISIPLEX INVESTMENTS LIMITED, A DELAWARE LIMITED PARTNERSHIP

By:/s/ Ben Joseph
   --------------------------------

            General Partner
   --------------------------------
                (Title)

MR. MICHAEL L. SWEENEY

By:/s/ Michael L. Sweeney
   --------------------------------

   --------------------------------
                (Title)

MS. LAURI S. GRUBB

By:/s/ Lauri S. Grubb
   --------------------------------

   --------------------------------
                (Title)


                                       30.
<PAGE>   34
I. P. (KIP) KNELMAN

By:/s/ I. P. (Kip) Knelman
   --------------------------------

   --------------------------------
                (Title)

MR. LARRY R. HILL

By:/s/ Larry R. Hill
   --------------------------------

   --------------------------------
                (Title)

MR. WARREN G. CHRISTIANSON

By:/s/ W. G. Christianson
   --------------------------------

   --------------------------------
                (Title)

THERESE ANDERSON

By:/s/ Therese M. Anderson
   --------------------------------

   --------------------------------
                (Title)

MR. HAROLD W. MILNER

By:/s/ Harold W. Milner
   --------------------------------

   --------------------------------
                (Title)


                                       31.
<PAGE>   35
DR. JEFFERY MCCULLOUGH

By:/s/ Jeffery McCullough
   --------------------------------

   --------------------------------
                (Title)

MR. PAUL K. JOAS

By:/s/ Paul K. Joas
   --------------------------------

   --------------------------------
                (Title)

CHERI L. AND THOMAS G. KAMP

By:/s/ Thomas G. Kamp
   --------------------------------

By:/s/ Cheri L. Kamp
   --------------------------------

   --------------------------------
                (Title)

MR. RICHARD E. STRUTHERS

By:/s/ Richard E. Struthers
   --------------------------------

   --------------------------------
                (Title)

ROBERT F. SHAW, M.D., TTEE ROBERT FRANCIS SHAW 1990 TRUST

By:/s/ Robert F. Shaw, M.D.
   --------------------------------
                Trustee
   --------------------------------
                (Title)


                                       32.
<PAGE>   36
CLEARWATER VENTURES, L.P.

By:/s/ Donald W. Weeden
   --------------------------------
           General Partner
   --------------------------------
                (Title)

MR. WAYNE G. JOHNSON

By:/s/ Wayne Johnson
   --------------------------------

   --------------------------------
                (Title)

MOTETE CORPORATION

By:/s/ Gabriel de la Guardia
   --------------------------------
             President
   --------------------------------
                (Title)

MR. DOUGLAS H. STICKNEY AND KIMBERLY A. STICKNEY

By:/s/ Douglas Stickney
   --------------------------------

By:/s/ Kimberly A. Stickney
   --------------------------------

   --------------------------------
                (Title)

MR. FRANK W. MCBEE JR.

By:/s/ Frank W. McBee
   --------------------------------

   --------------------------------
                (Title)


                                       33.
<PAGE>   37
MR. JAYE F. DYER

By:/s/ Jaye F. Dyer
   --------------------------------

   --------------------------------
                (Title)

N. BUD GROSSMAN REVOCABLE TRUST, DTD 8/22/83

By:/s/ N. Bud Grossman
   --------------------------------
                Trustee
   --------------------------------
                (Title)

MS. BEVERLY N. GROSSMAN

By:/s/ Beverly N. Grossman
   --------------------------------

   --------------------------------
                (Title)

MR. KENNETH W. STICKNEY

By:/s/ Ken W. Stickney
   --------------------------------

   --------------------------------
                (Title)

MR. ALBERTO PEREZ

By:/s/ Alberto Perez
   --------------------------------

   --------------------------------
                (Title)


                                       34.
<PAGE>   38
MR. JAMES DODGE

By:/s/ James Dodge
   --------------------------------------------

   --------------------------------------------
                      (Title)

MS. SUZANNE KNELMAN

By:/s/ Suzanne Knelman
   --------------------------------------------

   --------------------------------------------
                      (Title)

BAXTER HEALTHCARE CORPORATION

By:/s/ Victor Schmitt
   --------------------------------------------
   President, Venture Management, Biotech Group

   --------------------------------------------
                      (Title)

DR. HARRY B. GREENBERG

By:/s/ Harry Greenberg
   --------------------------------------------

   --------------------------------------------
                      (Title)

MR. STEVEN G. ROTHMEIER

By:/s/ Steven G. Rothmeier
   --------------------------------------------

   --------------------------------------------
                      (Title)


                                      35.
<PAGE>   39
MR. WAYNE MILLS

By:/s/ Wayne W. Mills
   ---------------------------------------

   ---------------------------------------
                      (Title)

MR. JEFF WERBALOWSKY

By:/s/ Jeffery Werbalowsky
   ---------------------------------------

   ---------------------------------------
                      (Title)

J. ROBERT COLEMAN & DIANE S. COLEMAN

By:/s/ Diane S. Coleman
   ---------------------------------------

By:/s/ J. Robert Coleman
   ---------------------------------------

   ---------------------------------------
                      (Title)

MR. NEIL N. LAPIDUS, C.P.A.

By:/s/ Neil Lapidus
   ---------------------------------------

   ---------------------------------------
                      (Title)

MS. ANNE F. HOLLORAN

By:/s/ Anne F. Holloran
   ---------------------------------------

   ---------------------------------------
                      (Title)


                                       36.
<PAGE>   40
CORAL PARTNERS II, A LIMITED PARTNERSHIP
By:  Coral Partners IV, Limited Partnership,
      its general partner

By:/s/ Peter H. McNerney
   ---------------------------------------
                  General Partner
   ---------------------------------------
                      (Title)

CORAL PARTNERS IV, LIMITED PARTNERSHIP

By:/s/ Peter H. McNerney
   ---------------------------------------
                  General Partner
   ---------------------------------------
                      (Title)

PETER H. MCNERNEY

By:/s/ Peter H. McNerney
   ---------------------------------------

   ---------------------------------------
                      (Title)

YUVAL ALMOG

By:/s/ Yuval Almog
   ---------------------------------------

   ---------------------------------------
                      (Title)

MR. MARK C. HEADRICK

By:/s/ Mark C. Headrick
   ---------------------------------------

   ---------------------------------------
                      (Title)


                                       37.
<PAGE>   41
LINDA L. WATCHMAKER

By:/s/ Linda L. Watchmaker
   ---------------------------------------

   ---------------------------------------
                      (Title)

LUCAS, DONALD A. C/F MARY A. LUCAS UTMA CA 21

By:/s/ Donald A. Lucas
   ---------------------------------------
                     Custodian
   ---------------------------------------
                      (Title)

LUCAS, DONALD A. C/F JACK B. LUCAS UTMA CA UNTIL AGE 21

By:/s/ Donald A. Lucas
   ---------------------------------------
                     Custodian
   ---------------------------------------
                      (Title)

KEN PREMINGER

By:/s/ Ken Preminger
   ---------------------------------------

   ---------------------------------------
                      (Title)

HEARST, DAVID PAUL IRREVOCABLE TRUST, U/A 4/7/89

By:/s/ John E. Hearst
   ---------------------------------------
                      Trustee
   ---------------------------------------
                      (Title)


                                       38.
<PAGE>   42
HEARST, LESLIE JEAN IRREVOCABLE TRUST, U/A 4/7/89

By:/s/ John E. Hearst
   ---------------------------------------
                      Trustee

   ---------------------------------------
                      (Title)

MR. JOHN E. HEARST

By:/s/ John E. Hearst
   ---------------------------------------

   ---------------------------------------
                      (Title)

MR. PETER HOWLEY

By:/s/ Peter Howley
   ---------------------------------------

   ---------------------------------------
                      (Title)

ANDREW L. CHASE OR LAURA A. CHASE, TTEES CHASE 1991 REVOCABLE TRUST, DTD
4/2/91

By:/s/ Andrew Chase
   ---------------------------------------

   ---------------------------------------
                      (Title)

ARNOLD N. SILVERMAN, TTEE SILVERMAN FAMILY TRUST DTD 6/22/88

By:/s/ Arnold N. Silverman
   ---------------------------------------
                     Truestee
   ---------------------------------------
                      (Title)


                                       39.
<PAGE>   43
CHASE 1991 REVOCABLE TRUST, DTD 4/2/91

By:/s/ Andrew Chase
   ---------------------------------------

   ---------------------------------------
                      (Title)

THIBODEAU, GEORGE M. C/F MICHAEL A. THIBODEAU UTMA CA 21

By:/s/ George M. Thibodeau
   ---------------------------------------
                     Custodian
   ---------------------------------------
                      (Title)

GC&H INVESTMENTS

By:/s/ Kenneth L. Guernsey
   ---------------------------------------
                 Executive Partner
   ---------------------------------------
                      (Title)

MR. JEFFREY L. WALKER

By:/s/ Jeffrey Walker
   ---------------------------------------

   ---------------------------------------
                      (Title)

THIBODEAU, GEORGE M., C/F ANN ALEANDRA THIBODEAU UTMA CA 21

By:/s/ George M. Thibodeau
   ---------------------------------------
                     Custodian
   ---------------------------------------
                      (Title)


                                       40.
<PAGE>   44
MS. LILY LIN

By:/s/ Lily Lin
   ---------------------------------------

   ---------------------------------------
                      (Title)

MR. HENRY RAPOPORT

By:/s/ Henry Rapoport
   ---------------------------------------

   ---------------------------------------
                      (Title)

MR. WALTER S. HUFF, JR.

By:/s/ Walter S. Huff
   ---------------------------------------

   ---------------------------------------
                      (Title)

LARRY G. GERDES IRREVOCABLE TRUST

By:/s/
   ---------------------------------------
                      Trustee
   ---------------------------------------
                      (Title)

GERDES HUFF INVESTMENTS

By:/s/ Larry Gerdes
   ---------------------------------------
                  General Partner
   ---------------------------------------
                      (Title)


                                       41.
<PAGE>   45
MR. LARRY G. GERDES

By:/s/ Larry Gerdes
   ---------------------------------------

   ---------------------------------------
                      (Title)

THE BC GROUP

By:/s/ Larry Gerdes
   ---------------------------------------
                       Agent
   ---------------------------------------
                      (Title)

HENRY STICKNEY, TRUSTEE OF THE STICKNEY FAMILY TRUST DTD 11/26/86

By:/s/ Henry E. Stickney
   ---------------------------------------
                      Trustee
   ---------------------------------------
                      (Title)

MR. B.J. CASSIN CONSERVATOR FOR ROBERT CASSIN

By:/s/ B. J. Cassin
   ---------------------------------------

   ---------------------------------------
                      (Title)

BRENDAN JOSEPH CASSIN AND ISABEL B. CASSIN, TRUSTEES OF THE CASSIN FAMILY TRUST
U/D/T DATED JANUARY 31, 1996

By:/s/ B. J. Cassin
   ---------------------------------------
                      Trustee
   ---------------------------------------
                      (Title)


                                       42.
<PAGE>   46
MR. JOHN TESSMAN

By:/s/ John Tessman
   ---------------------------------------

   ---------------------------------------
                      (Title)

CASSIN FAMILY PARTNERS, A CALIFORNIA LIMITED PARTNERSHIP

By:/s/ B. J. Cassin
   ---------------------------------------
                  General Partner
   ---------------------------------------
                      (Title)

THE TRUSTEES OF THE WALLACE R. HAWLEY AND ALEXANDRA HAWLEY REVOCABLE
TRUST U/A/D 07/30/92

By:/s/ Wallace R. Hawley
   ---------------------------------------
                      Trustee
   ---------------------------------------
                      (Title)

JANICE STICKNEY

By:/s/ Janice L. Stickney
   ---------------------------------------

   ---------------------------------------
                      (Title)

MR. GREGORY VAUGHAN

By:/s/ Gregory Vaughan
   ---------------------------------------

   ---------------------------------------
                      (Title)


                                       43.
<PAGE>   47
STEPHEN F. BULLOCK, TTEE STEPHEN F. BULLOCK & LINDA BULLOCK TRUST, DTD
11/15/90

By:/s/ Stephen F. Bullock
   --------------------------------------------------
                      Trustee
   --------------------------------------------------
                      (Title)

MR. ROBERT A. COOLEY

By:/s/ Robert A. Cooley
   --------------------------------------------------

   --------------------------------------------------
                      (Title)

STANFORD UNIVERSITY

By:/s/ Carol Gilmer
   --------------------------------------------------
   Assistant Secretary, the Board of
   Trustees of the Leland Standford Junior University
   --------------------------------------------------
                      (Title)

MR. RAYMOND BINGHAM

By:/s/ Raymond Bingham
   --------------------------------------------------

   --------------------------------------------------
                      (Title)

MR. RONALD P. ANTIPA

By:/s/ Ronald P. Antipa
   --------------------------------------------------

   --------------------------------------------------
                      (Title)


                                       44.
<PAGE>   48
DELAPORTA PARTNERSHIP

By:/s/ Angelo Delaporta
   ---------------------------------------
                  General Partner
   ---------------------------------------
                      (Title)

ANGELO DELLAPORTA, TRUSTEE DELLAPORTA FAMILY TRUST, DTD 8/16/82

By:/s/ Angelo Dellaporta
   ---------------------------------------
                      Trustee
   ---------------------------------------
                      (Title)

MR. STEPHEN T. ISAACS
   ---------------------------------------
By:/s/ Stephen Isaacs
   ---------------------------------------

   ---------------------------------------
                      (Title)


                                       45.
