Document:

<PAGE>   1
                                                                     EXHIBIT 4.3

                            B.I. SYSTEMS CORPORATION

                  SERIES B PREFERRED STOCK PURCHASE AGREEMENT

                            Dated as of May _, 1997

<PAGE>   2
                                TABLE OF CONTENTS

                                                                            Page

SECTION 1      AUTHORIZATION AND SALE .......................................  1
    1.1        Authorization of the Series B Preferred Stock ................  1
    1.2        Purchase and Sale of Series B Preferred Stock ................  1

SECTION 2      CLOSING DATE; DELIVERY .......................................  1
    2.1        Closing Date .................................................  1
    2.2        Delivery .....................................................  1
    2.3        Additional Closings ..........................................  2

SECTION 3      REPRESENTATIONS AND WARRANTIES OF THE COMPANY ................  2
    3.1        Organization and Standing; Charter and By-laws ...............  2
    3.2        Capitalization ...............................................  2
    3.3        Corporate Power; Authorization ...............................  3
    3.4        Validity of Securities .......................................  3
    3.5        Litigation ...................................................  3
    3.6        Employee Benefit Plans .......................................  3

SECTION 4      REPRESENTATIONS, WARRANTIES OF THE PURCHASERS AND
               RESTRICTIONS ON TRANSFER IMPOSED BY THE ACT ..................  4
    4.1        Representations and Warranties ...............................  4
               4.1.1 Authorization ..........................................  4
               4.1.2 Investment .............................................  4
               4.1.3 Federal Securities Law .................................  5
               4.1.4 State Securities Laws ..................................  5
    4.2        Transfer of Securities .......................................  5
               4.2.1 Legend .................................................  5
               4.2.2 Restrictions on Transfer ...............................  6
               4.2.3 Termination of Restrictions and Removal of Legend.......  6

SECTION 5      CONDITIONS TO OBLIGATIONS OF THE PURCHASERS ..................  7
    5.1        Representations and Warranties Correct; Performance of
               Obligations ..................................................  7
    5.2        Consents and Waivers .........................................  7
    5.3        Certificate of Incorporation..................................  7
    5.4        Minimum Proceeds .............................................  7
    5.5        Recapitalization .............................................  7

SECTION 6     CONDITIONS TO OBLIGATIONS OF THE COMPANY ......................  7

SECTION 7     RIGHT OF FIRST OFFER AND COVENANTS OF THE COMPANY  ............  8
    7.1        Right of First Offer .........................................  8
    7.2        Covenants ....................................................  9

                                       i
<PAGE>   3

    7.3        Termination .................................................. 10
    7.4        Right of First Refusal on Williams' Shares and the
               Purchasers' Shares ........................................... 11

SECTION 8      REGISTRATION RIGHTS .......................................... 13
    8.1        Definitions .................................................. 13
    8.2        Company Registration ......................................... 13
    8.3        Demand Registration .......................................... 14
    8.4        Obligations of the Company ................................... 14
    8.5        Furnish Information .......................................... 15
    8.6        Underwriting Requirements .................................... 15
    8.7        Delay of Registration ........................................ 16
    8.8        Indemnification .............................................. 16
    8.9        Reports Under Securities Exchange Act of 1934 ................ 18
    8.10       Form S-3 Registration ........................................ 18
    8.11       Expenses of Registration ..................................... 19
    8.12       Assignment of Registration Rights ............................ 19
    8.13       "Market Stand-Off" Agreement ................................. 19
    8.14       Limitations on Subsequent Registration Rights ................ 20
    8.15       Amendment of Registration Rights ............................. 20
    8.16       Termination .................................................. 20

SECTION 9      BOARD OF DIRECTORS ........................................... 20
    9.1        Composition of Board ......................................... 20
    9.2        Removal of Directors ......................................... 21
    9.3        Election of Directors ........................................ 21
    9.4        Voting Agreement ............................................. 21
    9.5        Termination .................................................. 21

SECTION 10     MISCELLANEOUS ................................................ 21
    10.1       Waivers and Amendments ....................................... 21
    10.2       Governing Law ................................................ 22
    10.3       Successors and Assigns ....................................... 22
    10.4       Entire Agreement ............................................. 22
    10.5       Notices, Etc ................................................. 22
    10.6       Delays or Omissions .......................................... 23
    10.7       Severability ................................................. 23
    10.8       Titles and Subtitles ......................................... 23
    10.9       Counterparts ................................................. 23
    10.10      Expenses ..................................................... 23

                                       ii
<PAGE>   4

EXHIBITS

     A.        Form of Amended and Restated Certificate of Incorporation

     B.        Description of Recapitalization

     C.        Form of Confidential Statement of Investor Suitability

SCHEDULES

     1.        Schedule of Purchasers

     4.1.3     Definition of Accredited Investor

                                      iii
<PAGE>   5

                  SERIES B PREFERRED STOCK PURCHASE AGREEMENT

         THIS SERIES B PREFERRED STOCK PURCHASE AGREEMENT (this "Agreement") is
dated as of the day of    May, 1997 by and among B.I. Systems Corporation, a
Delaware corporation (the "Company"), the persons listed on Schedule 1 attached
hereto (each of whom is referred to herein individually as a "Purchaser" and
collectively as the "Purchasers") and, solely for the purposes of Section 7.4,
Section 9 and Section 10 of this Agreement, Jeffrey S. Williams ("Williams").

                                   SECTION 1
                             AUTHORIZATION AND SALE

         1.1 Authorization of the Series B Preferred Stock. The Company has
authorized the sale and issuance of up to 2,000,000 shares of its Series B
Preferred Stock (the "Series B Shares") to the Purchasers thereof as listed on
Schedule 1 attached hereto. The Series B Shares shall have the rights,
privileges and preferences set forth in the Company's Amended and Restated
Certificate of Incorporation attached as Exhibit A hereto (the "Certificate of
Incorporation").

         1.2 Purchase and Sale of Series B Preferred Stock. Subject to the terms
and conditions hereof and in reliance upon the representations, warranties and
agreements contained herein, the Company agrees to issue and sell to the
Purchasers, and each of the Purchasers agrees to purchase from the Company, the
number of Series B Shares set forth opposite such Purchaser's name on Schedule 1
attached hereto, at a cash purchase price of $1.00 per share.

                                    SECTION 2
                             CLOSING DATE; DELIVERY

         2.1 Closing Date. The purchase and sale of the Series B Shares
hereunder shall occur at a closing (the "Closing") to be held at Mackowski &
Shepler, 343 Sansome Street, Suite 1215, San Francisco, California, on May 7,
1997 or at such other time and place as shall be mutually agreed upon by the
Company and the Purchasers (the "Closing Date").

         2.2 Delivery. Subject to the terms of this Agreement, at the Closing,
the Company will deliver to each of the Purchasers a certificate representing
the Series B Shares registered in such Purchaser's name equal to the number of
Series B Shares set forth opposite the name of such Purchaser on Schedule 1
attached hereto, against payment of the purchase price by (at the option of the
Company) either cashier's check payable in immediately available funds to the
order of the Company or by a wire transfer of funds to the order of the Company.

<PAGE>   6

         2.3 Additional Closings. The Company may sell up to the balance of the
authorized shares of Series B Preferred Stock not sold at the Closing as it
shall elect, at a price not less than $1.00 per share. Upon execution of a
signature page counterpart and without need for an amendment hereto except to
add such purchaser's name to Schedule 1 hereto, any such purchaser shall become
a party to this Agreement, shall be deemed a "Purchaser" for purposes of this
Agreement and shall have the rights and obligations hereunder.

                                    SECTION 3
                 REPRESENTATIONS AND WARRANTIES OF THE COMPANY

         Except as otherwise expressly indicated in the Schedules attached
hereto, the Company hereby represents and warrants to the Purchasers as follows:

         3.1 Organization and Standing; Charter and By-laws. The Company is a
corporation duly organized, validly existing and in good standing under the laws
of the State of Delaware, and the Company is authorized to exercise all of its
corporate powers, rights and privileges. True and accurate copies of the
Certificate of Incorporation and the by-laws of the Company, each as it will be
in effect at the Closing, have been delivered to the Purchasers.

         3.2 Capitalization. The authorized capital stock of the Company on the
date of the Closing will consist of 15,000,000 shares of $.001 par value common
stock ("Common Stock") and 4,000,000 shares of $.001 par value Preferred Stock
(the "Preferred Stock"), 2,000,000 of which have been designated Series B
Preferred Stock and 50,000 of which have been designated Series M Preferred
Stock. Assuming the completion of the recapitalization described in Exhibit B
attached hereto (the "Recapitalization"), no Preferred Stock will be outstanding
at the date of the Closing. The Series B Shares will have the rights,
preferences and privileges set forth in the Certificate of Incorporation. Upon
completion of the Recapitalization, there will be 31,280 shares of Common Stock
issued and outstanding. The Company has reserved 6,060,000 shares of Common
Stock for issuance upon conversion of the Series B Preferred Stock, 270,027
shares of Common Stock for issuance upon conversion of the Series M Preferred
Stock and 1,590,000 shares of Common Stock for issuance to employees,
consultants and directors under its 1994 Omnibus Equity Incentive Plan (the
"Stock Plan") pursuant to which, prior to the Recapitalization, options to
acquire an aggregate of 194,500 shares were outstanding. The Company intends to
offer the holders of such options the right to exchange their existing options
for new options which, upon completion of the Recapitalization, will entitle
them to acquire the number of shares of Common Stock specified in their existing
option agreement, but at an exercise price of $0.33 per share. The Stock Plan
was adopted by the Board of Directors and stockholders of the Company in July
1994 and amended in April 1997. Except as set forth herein or as described in
the description of the Recapitalization and except for the proposed sale of the
Series M Preferred Stock, there are no outstanding rights, options, warrants,
preemptive rights, conversion rights or agreements for the purchase, acquisition
or receipt from the Company of any shares of capital stock or any other
securities of the Company. The

                                       2
<PAGE>   7

Company is not a party to any existing agreement with any person or entity which
requires the Company to purchase from such person or entity any of its capital
stock, any securities convertible into or exchangeable or exercisable for any of
its capital stock, or any right, options or warrants for its capital stock. All
outstanding securities of the Company, including the Series B Shares, have been
issued in accordance with all applicable state and federal securities laws.

         3.3 Corporate Power; Authorization. The Company has all requisite legal
and corporate power to enter into this Agreement, to issue and sell the Series B
Shares as provided hereunder, and to carry out and perform its obligations under
the terms of this Agreement. All corporate action on the part of the Company and
its officers, directors and stockholders that is necessary for the
authorization, execution and delivery of this Agreement by the Company, for the
performance of the Company's obligations hereunder and for the issuance and
delivery of the Series B Shares has been taken; and this Agreement constitutes a
legal and binding obligation of the Company, enforceable against the Company in
accordance with its terms, subject to: (i) judicial principles respecting or
limiting the availability of specific performance, injunctive relief and other
equitable remedies; and (ii) bankruptcy, insolvency, reorganization, moratorium
or other similar laws now or hereafter in effect generally relating to or
affecting creditors' rights.

         3.4 Validity of Securities. The Series B Shares, when issued, sold and
delivered in accordance with the terms of this Agreement, will be duly and
validly issued, fully paid and nonassessable and will be free and clear of any
liens, encumbrances or restrictions of any kind; provided, however, that the
Series B Shares may be subject to restrictions on transfer under state and
federal securities laws. The Common Stock issuable upon conversion of the Series
B Shares has been duly and validly reserved and, upon issuance in accordance
with the terms of this Agreement and the Certificate of Incorporation, will be
duly and validly issued, fully paid and nonassessable and will be free and clear
of any liens, encumbrances or restrictions of any kind; provided, however, that
the Common Stock may be subject to restrictions on transfer under state and
federal securities laws.

         3.5 Litigation. There is no action, suit or proceeding pending or, to
the knowledge of the Company, threatened against the Company or related to the
business conducted by the Company. The Company is not a party or subject to the
provisions of any order, writ, injunction, judgment or decree of any court or
government agency or instrumentality. There is no action, suit, proceeding or
investigation by the Company currently pending or which the Company intends to
initiate.

         3.6 Employee Benefit Plans. Except for the Company's 401(k) Plan,
short-term and long-term disability plans, prescription drug plan and medical,
dental and life insurance plans, the Company does not have any Employee Benefit
Plan as defined in the Employee Retirement Income Security Act of 1974.

                                        3

<PAGE>   8

                                    SECTION 4
                  REPRESENTATIONS, WARRANTIES OF THE PURCHASERS
                 AND RESTRICTIONS ON TRANSFER IMPOSED BY THE ACT

         4.1 Representations and Warranties. Each Purchaser hereby represents
and warrants to the Company, severally and not jointly, and only as to itself,
as follows:

             4.1.1 Authorization. (a) All action on the part of such
Purchaser necessary for the execution, delivery and performance of this
Agreement, and the consummation of the transactions contemplated hereby has been
taken and, assuming due execution and delivery by the Company, this Agreement
constitutes a legal, valid, binding and enforceable obligation of such
Purchaser, subject to: (i) judicial principles respecting or limiting the
availability of specific performance, injunctive relief, and other equitable
remedies; and (ii) bankruptcy, insolvency, reorganization, moratorium or other
similar laws now or hereafter in effect generally relating to or affecting
creditors' rights.

             (b)   If the Purchaser is an entity, trust, pension fund or IRA
account (an "Entity"), the Entity and the person signing on its behalf represent
and warrant that: (i) such Entity is an existing entity, and has not been
organized or reorganized for the purpose of making this investment (or if not
true, such fact shall be disclosed to the Company in writing along with
information concerning the beneficial owners of the Entity), (ii) the
undersigned has the authority to execute this Agreement and the Confidential
Statement of Investor Suitability attached as Exhibit C hereto and any other
documents in connection with an investment in the Series B Shares on the
Entity's behalf, and (iii) the Entity has the power, right and authority to
invest in the Series B Shares and enter into the transactions contemplated
hereby, and the investment is suitable and appropriate for the Entity and its
beneficiaries (given the risks and illiquid nature of the investment).

             4.1.2 Investment.

             (a)   Such Purchaser has been advised that the Series B Shares have
not been registered under the Securities Act of 1933, as amended (the "Act"), or
registered or qualified under any applicable state securities laws on the ground
that no distribution or public offering of the Series B Shares is to be
effected, and that in this connection the Company is relying in part on the
representations of such Purchaser set forth in this Section 4;

             (b)   Such Purchaser has been further advised that no public market
now exists for any of the securities issued by the Company and that a public
market may never exist for the Series B Shares;

             (c)   Such Purchaser is purchasing the Series B Shares for its own
account and not for any other person;

             (d)   By reason of its business or financial experience, such
Purchaser has the capacity to protect its own interest in connection with the
transactions contemplated

                                        4

<PAGE>   9

hereunder, is able to bear the risks of an investment in the Company, and could
afford a complete loss of such investment;

             (e)   Such Purchaser is aware of the Company's business affairs and
financial condition and has acquired sufficient information about the Company to
reach an informed and knowledgeable decision to acquire the Series B Shares; and

             (f)   Such Purchaser has had the opportunity to ask questions
regarding the Company and the Company has provided information in response to
the questions.

             4.1.3 Federal Securities Law. In order to enable the Company to
determine whether the sale of the Series B Shares is exempt from registration
under the Act, such Purchaser represents that it is an Accredited Investor (as
defined in Schedule 4.1.3 hereof), has completed truthfully the appropriate
items in the Confidential Statement of Investor Suitability attached as Exhibit
C hereto, and is acquiring the Series B Shares for its own account, for
investment, and not with a view to, or for sale in connection with, any
distribution thereof.

             4.1.4 State Securities Laws. The address of such Purchaser set
forth on Schedule 1 attached hereto is the Purchaser's true and correct
residence or place of business.

         4.2 Transfer of Securities. Neither the Series B Shares nor the shares
of Common Stock issuable upon conversion of the Series B Shares shall be
transferable except upon the conditions specified in this Section 4.2, which
conditions are intended to insure compliance with the provisions of the Act with
respect to the transfer of such securities.

             4.2.1 Legend. Unless and until otherwise permitted by this Section
4.2, each certificate representing (i) the Series B Shares or (ii) the Company's
Common Stock issued upon conversion of the Series B Shares, will be endorsed
with a legend substantially in the following form:

         "THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
         1933, AS AMENDED, OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT
         BE SOLD, PLEDGED OR OTHERWISE TRANSFERRED UNLESS (A) COVERED BY AN
         EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933, AS
         AMENDED, AND ANY APPLICABLE STATE SECURITIES LAWS, OR (B) THE COMPANY
         HAS BEEN FURNISHED WITH AN OPINION OF COUNSEL ACCEPTABLE TO THE COMPANY
         TO THE EFFECT THAT SUCH SALE, PLEDGE OR TRANSFER IS EXEMPT FROM THE
         REGISTRATION AND PROSPECTUS DELIVERY REQUIREMENTS OF SAID

                                        5

<PAGE>   10

         SECURITIES ACT AND ANY APPLICABLE
         STATE SECURITIES LAWS."

             4.2.2 Restrictions on Transfer. The Series B Shares and the Common
Stock issuable upon the conversion of the Series B Shares shall not be sold,
assigned, pledged or transferred, and the Company shall not be required to
register any such sale, assignment, pledge or transfer, unless and until one of
the following events shall have occurred:

             (a)   the Company shall have received an opinion of counsel, in
form and substance reasonably acceptable to the Company and its counsel, stating
that the contemplated transfer is exempt from registration under the Act as then
in effect, and the Rules and Regulations of the Securities and Exchange
Commission (the "Commission") thereunder and any applicable state securities
laws;

             (b) the Company shall have been furnished with a letter from the
Commission in response to a written request in form and substance acceptable to
counsel for the Company setting forth all of the facts and circumstances
surrounding the contemplated sale, assignment, pledge or transfer, stating that
the Commission will take no action with regard to the contemplated sale,
assignment, pledge or transfer; or

             (c)   the Series B Shares, or the Common Stock issuable upon
conversion of the Series B Shares, are transferred pursuant to a registration
statement which has been filed with the Commission and has become effective.

         Within five business days after delivery to the Company and its counsel
of an opinion described in clause (a) above, the Company either shall deliver to
the proposed transferor a statement to the effect that such opinion is not
satisfactory in the reasonable opinion of its counsel (and shall specify in
detail the legal analysis supporting any such conclusion) or shall authorize the
Company's transfer agent to make the requested transfer. The restrictions set
forth in this Section 4.2.2 shall not apply to transfers by a Purchaser which is
a partnership to a current or former general or limited partner of such
partnership provided that the partner agrees in writing to be subject to the
terms hereof to the same extent as if he, she or it were a party hereto.

             4.2.3 Termination of Restrictions and Removal of Legend. The
restrictions on transfer imposed by this Section 4.2 shall cease and terminate
as to the Series B Shares and the Common Stock issuable upon conversion of the
Series B Shares, when (i) such securities (as applicable) shall have been
effectively registered under the Act and sold by the holder thereof in
accordance with such registration, or (ii) an acceptable opinion as described in
Section 4.2.2(a) or a "no action" letter described in Section 4.2.2(b) states
that all future transfers of such securities by the transferor or the
contemplated transferee would be exempt from registration under the Act. When
the restrictions on transfer contained in this Section 4.2 have terminated as
provided above, the holder of the securities as to which such restrictions shall
have terminated or the transferee of such

                                        6

<PAGE>   11

holder shall be entitled to receive promptly from the Company, without expense
to him, new certificates not bearing the legends set forth in Section 4.2.1
hereof.

                                    SECTION 5
                   CONDITIONS TO OBLIGATIONS OF THE PURCHASERS

         The obligation of the Purchasers to purchase the Series B Shares at the
Closing is subject to each of the following conditions having been fulfilled on
or prior to the Closing Date or waived by the Purchasers in accordance with the
provisions of Section 9.1 hereof:

         5.1 Representations and Warranties Correct; Performance of Obligations.
The representations and warranties made by the Company in Section 3 hereof shall
be true and correct when made, and shall be true and correct on the Closing Date
with the same force and effect as if they had been made on and as of the Closing
Date; and the Company shall have performed all obligations and conditions herein
required to be performed or observed by it on or prior to the Closing Date.

         5.2 Consents and Waivers. The Company shall have obtained any and all
consents, permits and waivers and made all filings necessary or appropriate for
consummation of the transactions contemplated by this Agreement.

         5.3 Certificate of Incorporation. The Certificate of Incorporation
shall have been filed with the Secretary of State of the State of Delaware.

         5.4 Minimum Proceeds. There shall be issued at the Closing, Series B
Shares with an aggregate purchase price of at least $850,000.

         5.5 Recapitalization. The Recapitalization shall have been completed
such that immediately prior to or simultaneously with the Closing the Company
shall have no outstanding Series A Preferred Stock and the Company shall have no
further obligations pursuant to its 15.0% Subordinated Debentures or the
promissory note issued to Millipore Corporation.

                                    SECTION 6
                    CONDITIONS TO OBLIGATIONS OF THE COMPANY

         The Company's obligation to issue, sell and deliver the Series B Shares
at the Closing is subject to the following conditions having been fulfilled on
or prior to the Closing Date or waived by the Company in accordance with the
provisions of Section 9.1 hereof: The representations and warranties made by the
Purchasers in Section 4 hereof shall be true and correct when made, and shall be
true and correct on the Closing Date with the same force and effect as if they
had been made on and as of the Closing Date and the conditions set forth in
Sections 5.2, 5.3, 5.4 and 5.5 hereof shall have been satisfied.

                                        7

<PAGE>   12

                                    SECTION 7
                RIGHT OF FIRST OFFER AND COVENANTS OF THE COMPANY

         7.1 Right of First Offer.

             (a) Subject to the terms and conditions specified in this Section
7.1, the Company hereby grants to each Purchaser a right to participate in
future sales by the Company of its Shares (as hereinafter defined). For purposes
of this Section 7.1 and Section 7.4, Purchaser includes any partners or retired
partners (including spouses and ancestors, lineal descendants and siblings of
such partners or spouses who acquire Series B Shares or Common Stock issued upon
conversion thereof by gift, will or intestate succession) of a Purchaser. A
Purchaser shall be entitled to apportion the right of first offer hereby granted
it among itself and its partners in such proportions as it deems appropriate.

             (b) Each time the Company proposes to offer any shares of, or
securities convertible into or exercisable for any shares of, any class of its
capital stock ("Shares"), the Company shall first make an offering of a portion
of such Shares (as determined in subsection (2) below) to each Purchaser in
accordance with the following provisions:

                 (1) The Company shall deliver a written notice ("Notice") to
             the Purchasers stating (i) its bona fide intention to offer such
             Shares, (ii) the number of such Shares to be offered, and (iii) the
             price and terms, if any, upon which it proposes to offer such
             Shares.

                 (2) Within 10 calendar days after receipt of the Notice, any
             Purchaser may elect to purchase or obtain, at the price and on the
             terms specified in the Notice, up to that portion of such Shares
             which equals the proportion (such Purchaser's "Proportion") that
             the number of shares of Common Stock held by such Purchaser
             (including for such calculation any shares issuable upon conversion
             of any capital stock convertible into Common Stock) bears to the
             total number of shares of Common Stock of the Company then
             outstanding held by the Purchasers and other persons who have been
             granted a right of first offer (assuming for such calculation any
             shares issuable upon conversion of any capital stock convertible
             into Common Stock).

                 (3) The Company may during the 10-day period following the
             expiration of the 10-day period provided in subsection (2) hereof,
             offer the remaining unsubscribed portion of such Shares which the
             Purchasers have not elected to purchase to any person or persons at
             a price not less than, and upon terms no more favorable to the
             offeree than those specified in the Notice. If the Company does not
             enter into an agreement for the sale of the Shares within 90 days
             of the expiration of such 10-day period, or if such agreement is
             not

                                       8
<PAGE>   13

             consummated within 120 days following the expiration of such 10-day
             period, the right provided hereunder shall be deemed to be revived
             and such Shares shall not be offered unless first reoffered to the
             Purchasers in accordance herewith.

                 (4) The right of first offer in this Section 7.1 shall not be
             applicable (i) to the issuance or sale of shares of Common Stock
             (as adjusted to reflect any stock splits, combinations or other
             events involving the Common Stock) to employees, consultants or
             members of the Board of Directors pursuant to employee or director
             stock plans which are approved in writing by the Company's Board of
             Directors, (ii) to the Public Offering (as defined in Section 7.3
             hereof) or to any offering of Shares after consummation of the
             Public Offering, (iii) to the issuance of securities pursuant to
             the conversion or exercise of presently outstanding convertible or
             exercisable securities, (iv) to any Common Stock issued upon
             conversion of the Series B Preferred Stock, the Series M Preferred
             Stock or other series of Preferred Stock issued pursuant to the
             Certificate of Incorporation, (v) to securities issued in
             connection with any acquisition or business combination transaction
             approved by the Board of Directors of the Company, or (vi) to
             securities issued in connection with equipment lease financings or
             other financings with commercial lenders or in strategic
             transactions involving the Company and other entities including
             joint ventures or marketing, distribution or development
             arrangements, in each case provided that any issuance pursuant to
             subsection (vi) has been approved by the Board of Directors of the
             Company.

         7.2 Covenants.

             (a) Taxes. The Company will promptly pay and discharge, or cause to
be paid and discharged, when due and payable, all lawful taxes, assessments, and
governmental charges or levies imposed upon the income, profits, property, or
business of the Company; provided, however, that any such tax, assessment,
charge, or levy need not be paid if the validity thereof shall currently be
contested in good faith by appropriate proceedings and if the Company shall have
set aside on its books adequate reserves with respect thereof.

             (b) Maintain Properties. The Company will keep its properties in
good repair, working order, and condition, reasonable wear and tear excepted,
and from time to time will make all necessary and proper repairs, renewals,
replacements, additions, and improvements thereto.

             (c) Maintain Corporate Existence. The Company shall maintain in
full force and effect its corporate existence, rights, and franchises and all
material licenses and other material rights to use processes, licenses,
trademarks, trade names, or copyrights

                                       9

<PAGE>   14

owned or possessed by it and deemed by the Company to be necessary to the
conduct of its business.

             (d) Insurance. The Company will maintain insurance of the types and
in the amounts generally deemed adequate for its business.

             (e) Without the approval in writing of the Company's Board of
Directors, the Company will not make or incur any expenditure (including,
without limitation, capital expenditures, acquisitions and capitalized leases)
or guarantee, assume or otherwise become directly or indirectly liable for any
indebtedness (including capitalized leases) which, individually or in
combination with related expenditures, guarantees or assumptions subject to a
common commitment, exceed $250,000.

             (f) Without the written consent of the holders of Series B Shares
and shares of Common Stock issued upon conversion of Series B Shares equivalent
to more than 66-2/3% of the total number of Series B Shares (treated as if
converted to Common Stock) and shares of Common Stock issued upon conversion of
Series B Shares, the Company will not (i) issue additional Shares except (A) up
to 2,000,000 Series B Shares issued pursuant to this Agreement, and (B) up to
50,000 shares of Series M Preferred Stock issued to Millipore Corporation, and
(C) Shares to which Section 7.1 is not applicable pursuant to clause (v) or
clause (vi) of Section 7.1(b)(4), but not more than 1,590,261 Shares
(appropriately adjusted for any stock splits, stock dividends, combinations and
similar events) or, if less, 20% of the then-outstanding Shares (outstanding
Preferred Stock being counted as if converted to Common Stock and other
outstanding convertible securities, warrants and options being counted as if
converted to, or exercised for, Common Stock), and (D) Shares to which Section
7.1 is not applicable pursuant to any of clauses (i) through (iv) of Section
7.l(b)(4); or (ii) merge or consolidate with or into any other entity or
recapitalize or effect a share exchange, except as permitted by the preceding,
clause (i); or (iii) grant any person preemptive rights or the right to purchase
Shares other than pursuant to employee or director stock plans which are
approved in writing by the Company's Board of Directors.

         7.3 Termination. The right of first offer set forth in Section 7.1,
the covenants set forth in Section 7.2 hereof and the right of first refusal set
forth in Section 7.4 hereof shall terminate upon the earlier to occur of (i) the
closing of a public offering pursuant to an effective registration statement
under the Securities Act of 1933, as amended, covering the offer and sale of the
Company's Common Stock where the gross proceeds to the Company are not less than
$7,500,000, where the public offering price is not less than $0.75 per share
(adjusted to reflect any stock splits, combinations or similar events after the
date hereof) and which results in the Company's Common Stock being traded on an
exchange or quoted on the National Association of Securities Dealers, Inc.
Automated Quotation ("NASDAQ") or quoted on the NASDAQ National Market System
(the "Public Offering") and (ii) the closing of the Company's sale of all or
substantially all of its assets or the acquisition of the Company by another
entity by means of merger or consolidation resulting in the exchange of the
outstanding shares of the Company's capital

                                       10

<PAGE>   15

stock for securities or consideration issued, or caused to be issued, by the
acquiring entity or its subsidiary.

         7.4 Right of First Refusal on Williams' Shares and the Purchasers'
Shares.

             7.4.1 If Williams or any Purchaser wishes to transfer any
securities of the Company issued to such person at any time (each such person, a
"Selling Stockholder") except in a Permitted Transfer, the Selling Stockholder
shall do so only for cash, unsecured promissory notes, cash equivalents, or a
combination of the foregoing, and shall first give written notice (the "Offer
Notice") to the Company, identifying the securities proposed to be transferred
(the "Offered Securities"), identifying the proposed transferee, and stating the
price at which, and other material terms on which, the Selling Stockholder
wishes to transfer the Offered Securities, including the date of the proposed
transfer.

             7.4.2 Delivery of an Offer Notice to the Company shall constitute
an offer to transfer the Offered Securities, in whole but not in part (the
"Offer"), first to the Company, and then to the Purchasers, pursuant to this
Section 7.4, at the price and on the other material terms described in the Offer
Notice.

             7.4.3 Within seven calendar days after it receives an Offer Notice,
the Company will deliver a copy of the Offer Notice to each Purchaser.

             7.4.4 The Company may elect, by written notice delivered to the
Selling Stockholder not later than fourteen calendar days after the Company
receives the Offer Notice, to accept the Offer with respect to all of the
Offered Securities.

             7.4.5 If the Company does not elect to accept an Offer, then within
seven calendar days after the expiration of the period specified in Section
7.4.4, the Company will notify each Purchaser of the Purchaser's rights under
Section 7.4.6.

             7.4.6 If the Company does not elect to accept an Offer within the
period specified in Section 7.4.4, then each of the Purchasers may elect to
accept the Offer with respect to all or any portion of the Offered Securities,
but at least the Purchaser's Proportion of the Offered Securities, by written
notice delivered to the Company not later than twenty-one calendar days after
the Purchaser received the Offer Notice.

             7.4.7 If Purchasers which accept the Offer ("Participants") elect,
in the aggregate, to accept all of an Offer, then the Participants shall
participate in the purchase of the Offered Securities in the following
proportions:

                    (a) first, each Participant shall purchase the Participant's
         Proportion of the Offered Securities, and

                                       11
<PAGE>   16

                    (b) then, if there are any Offered Securities remaining
         unpurchased, those Participants who elected to purchase more than
         their Proportion shall purchase the remaining Offered Securities in
         the relative proportions of the amounts by which each of them elected
         to purchase more than his, her or its Proportion,

or in such other proportions on which the Participants shall agree.

             7.4.8  If the Company or Participants elect to accept an Offer in
its entirety, then the Selling Stockholder shall transfer the Offered Securities
to the Company or the Participants, as the case may be, and the Company or the
Participants, as the case may be, shall acquire the Offered Securities, at the
price and on the other material terms described in the Offer Notice. The
consummation of the transfer shall take place at the chief executive offices of
the Company, on the date specified for the proposed transfer in the Offer Notice
(but not earlier than sixty-three calendar days after the Company shall have
received the Offer Notice), or at such other location or date on which the
participants in the transaction agree in writing.

             7.4.9  If neither the Company nor Participants accept an Offer in
its entirety, then the Selling Stockholder may transfer the Offered Securities
(subject to the provisions of this Agreement other than this Section 7.4 and to
any other agreements binding on the Selling Stockholder) to the transferee named
in the Offer Notice, at any time within the period of 120 calendar days
beginning on the date the Company received the Offer Notice. The provisions of
this Section 7.4 shall again apply to any transfer of Offered Securities not
transferred within such period.

             7.4.10 A "Permitted Transfer" is a transfer of securities to a
Permitted Transferee if, prior to the consummation of the transfer, the
Permitted Transferee shall have agreed in writing to be bound as a party to this
Agreement by all the terms of this Agreement applicable to the Selling
Stockholder. A "Permitted Transferee" means any of:

                    (a) the spouse or a lineal ancestor or descendant (whether
         natural or adopted) of the transferor;

                    (b) a trust all the beneficiaries (primary and contingent)
         of which are either the transferor or the spouse or a lineal ancestor
         or descendant (natural or adopted) of the transferor; or

                    (c) a partner in a transferor which is a partnership, or a
         stockholder of a transferor which is a limited liability company, which
         person receives the transfer as part of a distribution among partners,
         stockholders, or members, as the case may be, of the transferor.

                                       12

<PAGE>   17

                                    SECTION 8
                               REGISTRATION RIGHTS

         The Company covenants and agrees as follows:

         8.1 Definitions. For purposes of this Section 8:

             (a) The term "register", "registered," and "registration" refer to
a registration effected by preparing and filing a registration statement or
similar document in compliance with the Act, and the declaration or ordering of
effectiveness of such registration statement or document;

             (b) The term "Registrable Securities" means (i) the Common Stock
issuable or issued upon conversion of the Series B Preferred Stock or the Series
M Preferred Stock 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 Series B Preferred Stock or Series M
Preferred Stock, other Preferred Stock or Common Stock; provided, however, that
Common Stock or other securities shall only be treated as Registrable Securities
if and so long as (1) they have not been sold to or through a broker or dealer
or underwriter in a public distribution or a public securities transaction, and
(2) they have not been sold in a transaction exempt from the registration and
prospectus delivery requirements of the Act under Section 4(l) thereof so that
all transfer restrictions and restrictive legends with respect thereto are
removed upon the consummation of such sale;

             (c) The number of shares of "Registrable Securities then
outstanding" shall be determined by the number of shares of Common Stock
outstanding which are, and the number of shares of Common Stock issuable
pursuant to then exercisable or convertible securities which are, Registrable
Securities;

             (d) The term "Holder" means any person who is the record owner of
Registrable Securities or the Series B Shares or the Series M Shares, or any
assignee thereof in accordance with Section 8.12 hereof; and

             (e) The term "SEC" means the Securities and Exchange Commission or
any other federal agency at the time administering the Act.

         8.2 Company Registration. If (but without any obligation to do so) the
Company proposes to register any of its stock or other securities under the Act
in connection with the public offering of such securities solely for cash (other
than a registration relating solely to the sale of securities to participants in
a Company stock plan, or a registration on any form which does not include
substantially the same information as would be required to be included in a
registration statement covering the sale of the Registrable Securities or a SEC
Rule 145 transaction), the Company shall, at such time, promptly give each
Holder written notice of such registration. Upon the written request of

                                       13

<PAGE>   18

each Holder given within fifteen (15) days after mailing of such notice by the
Company in accordance with Section 10.5, the Company shall, subject to the
provisions of Sections 8.4, 8.5, 8.6 and 8.7, cause to be registered under the
Act all of the Registrable Securities that each such Holder has requested to be
registered. Notwithstanding the foregoing, after the Company's initial public
offering, the Company will not be required to give notice to the Holders of
Registrable Securities if the underwriters managing the proposed offering have
advised the Company in writing that in their judgment market conditions will not
allow the inclusion of any secondary shares in such offering. In the event the
managing underwriters and the Company subsequently determine to add any
secondary shares in the offering, such notice shall be provided, and each Holder
shall have the registration rights provided in this Section 8.

         8.3 Demand Registration. Subject to the terms of this Agreement, in
the event that the Company shall receive from the Holders of Series B Shares (or
Common Stock issued upon conversion of Series B Shares) representing at least
thirty percent (30%) of the Registrable Securities then outstanding, the Holders
of Series M Preferred Stock), at any time after six (6) months after the
effective date of the registration statement covering the Company's initial
public offering, a written notice that it or they intend to offer or cause to be
offered for public sale at least twenty-five percent (25%) of the Registrable
Securities then outstanding (or any lesser percentage if the aggregate offering
price to the public is greater than $5,000,000), the Company will so notify all
Holders. Upon written request of any Holder given within fifteen (15) days after
the receipt by such Holder from the Company of such notification, the Company
will use its best efforts to cause such of the Registrable Securities as may be
requested by any Holder (including the Holder giving the initial notice of
intent to offer) to be registered under the Securities Act as expeditiously as
possible (a "Demand Registration"). The Company shall not be required to effect
more than one (1) Demand Registration. If (i) in the good faith judgment of the
Board of Directors of the Company, a Demand Registration would be materially
detrimental to the Company and the Board of Directors of the Company concludes,
as a result, that it is essential to defer the filing of such registration
statement at such time, and (ii) the Company shall furnish to each Holder 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 materially
detrimental to the Company for such registration statement to be filed in the
near future, then the Company shall have the right to defer such filing for the
period during which such Demand Registration would be materially detrimental,
provided that the Company may not defer the filing for a period of more than
ninety (90) days after receipt of the request for a Demand Registration, and
more than once in any 12-month period.

         8.4 Obligations of the Company. Whenever required under Section 8.2 or
8.3 to effect the registration of any Registrable Securities, 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

                                       14

<PAGE>   19

up to 90 days or until all of the securities registered thereunder are sold,
whichever occurs sooner.

             (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
Act with respect to the disposition of all securities covered by such
registration statement.

             (c) Furnish to the Holders such numbers of copies of a prospectus,
including a preliminary prospectus, in conformity with the requirements of the
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.

             (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 of such offering. Each Holder
participating in such underwriting shall 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 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 therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing.

         8.5 Furnish Information. It shall be a condition precedent to the
obligations of the Company to take any action pursuant to this Section 8 with
respect to the Registrable Securities of any selling Holder that such Holder
shall furnish to the Company such information regarding itself, the Registrable
Securities held by it and the intended method of disposition of such securities
as shall be required to effect the registration of such Holder's Registrable
Securities.

         8.6 Underwriting Requirements. In connection with any offering
involving an underwriting of shares of the Company's capital stock, the Company
shall not be required under Section 8.2 or 8.3 to include any of the Holders'
securities in such underwriting unless they accept the terms of the underwriting
as agreed upon between the Company and the underwriters selected by the persons
entitled to select the underwriters, and then only in such quantity as the
underwriters determine in their sole discretion will not jeopardize the success
of the offering by the Company. If the total amount of securities, including
Registrable Securities, requested by Holders to be included in such offering

                                       15

<PAGE>   20
exceeds the amount of securities sold other than by the Company that the
underwriters determine in their sole discretion is compatible with the success
of the offering, then the Company shall be required to include in the offering
only that number of such securities, including Registrable Securities, which the
underwriters determine in their sole discretion will not jeopardize the success
of the offering (the securities so included to be apportioned pro rata among all
selling stockholders according to the total amount of securities owned by each
selling stockholder or in such other proportions as shall mutually be agreed to
by such selling stockholders). For purposes of the preceding parenthetical
concerning apportionment, for any selling stockholder which is a holder of
Registrable Securities and which is a partnership or corporation, the partners,
retired partners and stockholders 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
stockholder" and any pro-rata reduction with respect to such "selling
stockholder" shall be based upon the aggregate amount of shares owned by all
entities and individuals included in such "selling stockholder," as defined in
this sentence.

         8.7 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 Section 8.

         8.8 Indemnification. In the event any Registrable Securities are
included in a registration statement under this Section 8:

             (a) To the extent permitted by law, the Company will indemnify and
hold harmless each Holder, any underwriter (as defined in the Act) for such
Holder and each person, if any, who controls such Holder or underwriter within
the meaning of the 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 Act, or 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"): (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 therein 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 Act, the 1934 Act, any state securities law or any rule or
regulation promulgated under the Act, or the 1934 Act or any state securities
law; and the Company will pay to each such Holder, underwriter or controlling
person, as incurred, any legal or other expenses reasonably incurred by one law
firm retained by them (or such additional law firms retained by a Holder or
Holders if such Holder or Holders reasonably believe there exists a conflict of
interest among them) in connection with investigating or defending any such
loss, claim, damage, liability or action; provided, however, that the indemnity
agreement contained in this subsection 8.8(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

                                       16

<PAGE>   21
(which consent shall not be unreasonably withheld), nor shall the Company be
liable in any, such case for any 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 any such Holder, underwriter or
controlling person.

             (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 has signed the registration statement, each person, if any, who
controls the Company within the meaning of the Act, any underwriter, any other
Holder selling securities in such registration statement and any controlling
person of any such underwriter or other Holder, against any losses, claims,
damages or liabilities (joint or several) to which any of the foregoing persons
may become subject, under the Act, or 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 pay, as
incurred, any legal or other expenses reasonably incurred by any person intended
to be indemnified pursuant to this subsection 8.8(b), in connection with
investigating or defending any such loss, claim, damage, liability or action;
provided, however, that the indemnity agreement contained in this subsection
8.8(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; provided, that,
in no event shall any indemnity under this subsection 8.8(b) exceed the net
proceeds from the offering received by such Holder.

             (c) Promptly after receipt by an indemnified party under this
Section 8.8 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 8.8, 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
(together with all other indemnified parties which may be represented without
conflict by one counsel) shall have the right to retain one separate counsel,
with the fees and expenses to be paid by the indemnifying 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 prejudicial to its ability to defend such action, shall relieve such
indemnifying party of any liability to the indemnified party under this Section
8.8, but the failure to deliver written notice to the indemnifying party will
not relieve it of any liability that it may have to any indemnified party
otherwise than under this Section 8.8.

                                       17
<PAGE>   22

                  (d) The obligations of the Company and Holders under this
Section 8.8 shall survive the completion of any offering of Registrable
Securities in a registration statement under this Section 8, and otherwise.

         8.9 Reports Under Securities Exchange Act of 1934. With a view to
making available to the Holders the benefits of Rule 144 promulgated under the
Act and any other rule or regulation of the SEC that may at any time permit a
Holder to sell securities of the Company to the public without registration, the
Company agrees to:

                  (a) make and keep public information available, as those terms
are understood and defined in SEC Rule 144, at all times after ninety (90) days
after the effective date of the first registration statement filed by the
Company for the offering of its securities to the general public;

                  (b) file with the SEC in a timely manner all reports and other
documents required of the Company under the Act and the 1934 Act; and

                  (c) furnish to any Holder, so long as the Holder owns any
Registrable Securities, forthwith upon request (i) a written statement by the
Company that it has complied with the reporting requirements of SEC Rule 144 (at
any time after ninety (90) days after the effective date of the first
registration statement filed by the Company), the Act and the 1934 Act (at any
time after it has become subject to such reporting requirements), (ii) a copy of
the most recent annual or quarterly report of the Company and such other reports
and documents so filed by the Company, and (iii) such other information as may
be reasonably requested in availing any Holder of any rule or regulation of the
SEC which permits the selling of any such securities without registration or
pursuant to such form.

         8.10 Form S-3 Registration. In case the Company shall receive from any
Holder or Holders of the Registrable Securities then outstanding a written
request or requests that the Company effect a registration on Form S-3 for a
public offering the aggregate offering price of which would exceed $1,000,000,
the Company will:

                  (a) promptly give written notice of the proposed registration,
and any related qualification or compliance, to all other Holders; 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 Holder's
or Holders' Registrable Securities as are specified in such request, together
with all or such portion of the Registrable Securities of any other Holder or
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 8.10:
(i) if Form S-3 is not available for such offering by the Holders; (ii) if the
Company shall furnish to the Holders a certificate signed by the President of
the Company stating that in the good

                                       18

<PAGE>   23

faith judgment of the Board of Directors of the Company it would be detrimental
to the Company and its stockholders 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 8.10; (iii) if the Company has, within the twelve (12) month
period preceding the date of such request, already effected two registrations
for the Holders pursuant to Section 8.2, 8.3 or this Section 8.10; or (iv) 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
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.

         8.11 Expenses of Registration. The Company shall bear and pay all
expenses incurred in connection with any registration, filing or qualification
of Registrable Securities with respect to a total of three registrations,
whether pursuant to Section 8.2, 8.3 or 8.10 or a combination thereof,
including (without limitation) all registration, filing, and qualification fees,
printers and accounting fees relating or apportionable thereto and the fees and
disbursements of one counsel for the selling Holders selected by them (which the
Company may request be the Company's counsel if such counsel is reasonably
acceptable to such selling Holders), but excluding underwriting discounts and
commissions and stock transfer taxes relating to Registrable Securities.

         8.12 Assignment of Registration Rights. The rights to cause the Company
to register Registrable Securities pursuant to this Section 8 may only be
assigned to a purchaser, assignee or transferee of the underlying Registrable
Securities.

         8.13 "Market Stand-Off" Agreement. Each Purchaser hereby agrees that
for a period of 180 days following the effective date of the first registration
statement of the Company covering common stock filed on Form S-1 under the Act
and for any registration effected pursuant to Sections 8.2, 8.3 or 8.10
(provided the Holders are given written notice of the offering at least fifteen
(15) days prior to the Company's filing with the SEC of a registration statement
relating thereto), it shall not, unless otherwise agreed by the Company and the
managing underwriters, 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 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
Purchaser (and

                                       19
<PAGE>   24

the shares or securities of every other person subject to the foregoing
restriction) until the end of such period.

         8.14 Limitations on Subsequent Registration Rights. From and after the
date of this Agreement, the Company shall not, without the prior written consent
of the Holders of a majority of the outstanding Registrable Securities, enter
into any agreement with any holder or prospective holder of any securities of
the Company which would allow such holder or prospective holder to include such
securities in any registration filed under Section 8.2, 8.3 or 8.10 hereof,
unless under the terms of such agreement, such holder or prospective holder may
include such securities in any such registration only to the extent that the
inclusion of his securities will not reduce the amount of the Registrable
Securities of the Holders which is included.

         8.15 Amendment of Registration Rights. Any provision of this Section 8
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 a majority of the Registrable
Securities then outstanding. Any amendment or waiver effected in accordance with
this paragraph shall be binding upon each holder of any Registrable Securities
then outstanding, each future holder of all such Registrable Securities, and the
Company.

         8.16 Termination. The rights provided in this Section 8 shall terminate
on the fifth anniversary of the closing of the Company's initial public offering
pursuant to which the Company registers shares of Common Stock under the Act and
following shortly thereafter or concurrently therewith registers its Common
Stock under the 1934 Act.

                                    SECTION 9
                               BOARD OF DIRECTORS

         9.1 Composition of Board. The Company, each of the Purchasers and
Williams agree that, so long as the Voting Agreement set forth in this Section
remains in effect, each of them shall take all action necessary from time to
time (including, without limitation, the voting of securities of the Company,
the execution of written consents, the calling of special meetings, the removal
of directors, the filling of vacancies on the Board, the waiving of notice and
attendance at meetings) to maintain the membership of the Board as follows:

                  (a) The chief executive officer of the Company shall serve as
a director of the Company;

                  (b) As long as it owns stock of the Company, American
Healthcare Fund II, L.P. shall have the right to designate one person to serve

as a director of the Company;

                                       20

<PAGE>   25

                  (c) As long as either Matthew Mackowski ("Mackowski") or
Robert Shepler ("Shepler") owns stock of the Company, Mackowski and Shepler
shall each have the right to designate one person to serve as a director of the
Company; and

                  (d) The remaining directors shall be designated by the
unanimous consent of the directors designated under clause (a), (b) and (c) of
this Section 9.1.

The person or persons entitled to name a director pursuant to clause (b), (c) or
(d) of this Section 9.1, as the case may be, are referred to in this Section as
the "Principals" with respect to that director. Notwithstanding the foregoing,
the right of each Principal to name a director pursuant to clause (b) or (c)
above shall terminate if such Principal owns Shares equivalent to less than
fifty percent (50%) of the aggregate number of Shares held by such Principal
(Preferred Stock being counted as if converted to Common Stock) immediately
after the last Closing pursuant to Section 2.1 or 2.3 of this Agreement.

         9.2 Removal of Directors. If Principals give notice at any time to the
Company, the other Purchasers and Williams that the individual then serving as a
director of the Company at such Principals' designation is no longer their
designee, then the Company, the Purchasers and Williams shall take all action
necessary to remove the director so designated.

         9.3 Election of Directors. If an individual serving at any time as a
director of the Company dies, or resigns, or is removed as a director of the
Company, then the Company, the Purchasers and Williams shall take all action
necessary to elect as a director of the Company any individual newly designated
by the Principals with respect to the director who died, or resigned, or was
removed.

         9.4 Voting Agreement. These Sections 9.1 through 9.4 are intended to be
a voting agreement within the meaning of Section 218 of the Delaware General
Corporation Law.

         9.5 Termination. The rights and obligations provided in this Section 9
shall terminate upon the closing of the Company's initial public offering
pursuant to which the Company registers shares of its Common Stock under the
Act.

                                   SECTION 10
                                 MISCELLANEOUS

         10.1 Waivers and Amendments. Except as to Section 8 in which case the
provisions of Section 8.15 shall apply, with the written consent of the record
or beneficial holders of more than 66-2/3 % of the aggregate of (i) the then
outstanding number of shares of the Series B Shares (treated as if converted to
Common Stock) and (ii) all shares of Common Stock obtained upon conversion of
the Series B Shares, the obligations of the

                                       21
<PAGE>   26

Company and the rights of the holders of Series B Shares and the Common Stock
obtained upon conversion of the Series B Shares under this Agreement may be
waived (either generally or in a particular instance, either retroactively or
prospectively and either for a specified period of time or indefinitely), and
with the same consent the Company, when authorized by resolution of its board of
directors, may enter into a supplementary agreement for the purpose of adding
any provisions to or changing in any manner or eliminating any of the provisions
of this Agreement; provided, however, that no such waiver or supplemental
agreement shall reduce the aforesaid percentages which are required to consent
to any waiver or supplemental agreement, without the unanimous consent of the
record or beneficial holders of all of the then outstanding number of shares of
the Series B Shares or the shares of Common Stock obtained upon conversion of
the Series B Shares. Upon the effectuation of each such waiver, consent,
agreement of amendment or modification, the Company promptly shall give written
notice thereof to the record holders of the then outstanding Series B Shares and
the shares of Common Stock obtained upon conversion of the Series B Shares. This
Agreement or any provision hereof may not be changed, waived, discharged or
terminated orally, but only by a statement in writing signed by the party
against which enforcement of the change, waiver, discharge or termination is
sought, except to the extent provided in this Section 10.1; provided, however,
that the conditions to Closing contained in Section 5 of this Agreement may only
be waived by the Purchaser for itself.

         10.2 Governing Law. This Agreement shall be governed in all respects by
the laws of the State of Delaware as such laws are applied to agreements between
Delaware residents entered into and to be performed entirely within Delaware.

         10.3 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.

         10.4 Entire Agreement. This Agreement and the other documents delivered
pursuant hereto constitute the full and entire understanding and agreement
between the parties with regard to the subjects hereof and thereof.

         10.5 Notices, Etc. All notices and other communications required or
permitted hereunder shall be in writing and shall be deemed effectively given
upon personal delivery or upon the seventh day following mailing by registered
air mail, postage prepaid, addressed (a) if to the Purchasers, as indicated on
Schedule 1 attached hereto, or at such other address as it shall have furnished
to the Company, (b) if to the Company, to B.I. Systems Corporation, 525 Avis
Drive, Ann Arbor, Michigan, 48108, and addressed to the attention of the
corporate secretary, or at such other address as the Company shall have
furnished to the Purchasers, or (c) if to any other holder of the Series B
Shares or of Common Stock issued upon conversion of the Series B Shares at such
address as such holder shall have furnished to the Company in writing, or, until
such holder so furnishes an address to the Company, then to and at the address
of the last holder of such Series B Shares or shares of Common Stock issued upon
conversion of the Series B Shares, who so

                                       22
<PAGE>   27

furnished an address to the Company. In addition, any notice delivered to an
address outside the United States shall be duplicated by counterpart telex
notice (if available).

         10.6 Delays or Omissions. No delay or omission to exercise any right,
power or remedy accruing to any holder of any securities issued or sold or to be
issued or sold hereunder, upon any breach or default of the Company under this
Agreement shall impair any such right, power or remedy of such holder nor shall
it be construed to be a waiver of any such breach or default, or an acquiescence
therein, or in any similar breach or default thereafter occurring, nor shall any
waiver of any single breach or default be deemed a waiver of any other breach or
default theretofore or thereafter occurring. Any waiver, permit, consent or
approval of any kind or character on the part of any holder of any breach or
default under this Agreement, or any waiver on the part of any holder 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 or by law or otherwise afforded to any
holder, shall be cumulative and not alternative.

         10.7 Severability. In case any provision of this Agreement shall be
invalid, illegal or unenforceable, it shall be modified in such manner as to be
valid, legal, and enforceable but so as to most nearly retain the intent of the
parties, and the validity, legality and enforceability of the remaining
provisions of this Agreement shall not in any way be affected or impaired
thereby.

         10.8 Titles and Subtitles. The titles and subtitles of this Agreement
are intended for reference and shall not by themselves determine the
construction or interpretation of this Agreement.

         10.9 Counterparts. This Agreement may be executed in any number of
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

         10.10 Expenses. The Company and each Purchaser shall pay its own costs
and expenses in connection with the negotiation, execution, delivery and
performance of this Agreement.

         [THE REMAINDER OF THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK]

                                       23

<PAGE>   28

         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed themselves or by their respective representatives thereunto duly
authorized as of the day and year first above written.

                                  B.I. SYSTEMS CORPORATION

                                  By:
                                     -----------------------------------------
                                               Jeffrey S. Williams
                                       President and Chief Executive Officer

                                  --------------------------------------------
                                  Jeffrey S. Williams, in his individual
                                  capacity but only as to Section 7.4, Section 9
                                  and Section 10 of this Agreement

                        THE PURCHASERS SIGNATURES ARE ON
                     THE ATTACHED PURCHASER SIGNATURE PAGES.

                      SIGNATURE PAGE TO SERIES B PREFERRED
                            STOCK PURCHASE AGREEMENT

                                       24

<PAGE>   29

                            PURCHASER SIGNATURE PAGE

Please indicate the number of Series B Shares which you would like to purchase.

-----------

(Please note: As described in the Description of Recapitalization attached
hereto as Exhibit B, each existing stockholder of the Company is being offered
the right to purchase a specified percentage of the shares of Series B Preferred
offered hereby (each, an "Allocation"). If all existing stockholders do not
purchase the full amount of their Allocation, you may be able to purchase more
than your Allocation. Accordingly, the number of shares which you indicate above
may be greater than, equal to or less than your Allocation, but, if such number
is greater than your Allocation, there can be no assurance that you will be able
to purchase all of such shares.)

                                  PURCHASER:

                                  -----------------------------------------
                                                  SIGNATURE

                                  Name:
                                       ------------------------------------
                                                (Please Print)

                                  Title, if any:
                                                ---------------------------
                                                (Please Print)

                                  ADDRESS:

                                  -----------------------------------------

                                  -----------------------------------------

                                  -----------------------------------------
                                  Attn:
                                       ------------------------------------

                                  Tax ID No. or Social Security
                                  No., as applicable:
                                                     ----------------------

                                       25

<PAGE>   30

                            PURCHASER SIGNATURE PAGE

Please indicate the number of Series B Shares which you would like to purchase.

-----------

(Please note: As described in the Description of Recapitalization attached
hereto as Exhibit B, each existing stockholder of the Company is being offered
the right to purchase a specified percentage of the shares of Series B Preferred
offered hereby (each, an "Allocation"). If all existing stockholders do not
purchase the full amount of their Allocation, you may be able to purchase more
than your Allocation. Accordingly, the number of shares which you indicate above
may be greater than, equal to or less than your Allocation, but, if such number
is greater than your Allocation, there can be no assurance that you will be able
to purchase all of such shares

                                  PURCHASER:

                                  AMERICAN HEALTHCARE FUND II, L.P.
                                  a Delaware limited partnership

                                  By: Capital Health Venture Partners, its
                                      general partner

                                  By:
                                      --------------------------------------
                                      Dan J. Mitchell, General Partner

                                  ADDRESS:

                                  -----------------------------------------

                                  -----------------------------------------

                                  -----------------------------------------
                                  Attn:
                                       ------------------------------------

                                  Tax ID No. or Social Security
                                  No., as applicable:
                                                     ----------------------

                                       25

<PAGE>   31

                               FIRST AMENDMENT TO
                  SERIES B PREFERRED STOCK PURCHASE AGREEMENT

         THIS FIRST AMENDMENT TO SERIES B PREFERRED STOCK PURCHASE AGREEMENT
(the "Amendment") is dated as of April 23, 1999, and is made by GENOMIC
SOLUTIONS INC., a Delaware corporation (the "Company"), pursuant to Section 8.15
of the Series B Preferred Stock Purchase Agreement dated as of May 7, 1997 (the
"Agreement"), by and between the Company, certain persons (the "B Investors")
and for certain specified purposes, Jeffrey S. Williams ("Williams").
Capitalized terms not otherwise defined in this Amendment shall have the
meanings set forth in the Agreement.

                                   RECITALS:

         A. The Company, the B Investors and Williams entered into the
Agreement, pursuant to which the B Investors acquired the Series B Shares and
which provides for certain rights, privileges and restrictions applicable to the
Series B Shares.

         B. The Company has authorized an additional borrowing of $6,000,000
from certain lenders (the "Lenders") in exchange for the issuance by the Company
to the Lenders of subordinated promissory notes in the aggregate amount of
$6,000,000 providing for, among other things, quarterly interest payments at 12%
per annum and a five-year maturity, together with warrants to acquire up to
1,400,000 Shares of Common Stock with certain registration rights (the
"Warrants)

         C. Under Section 8.15 of the Agreement, any provision of Section 8 of
the Agreement may be amended with the written consent of the Company and the
holders of a majority of the shares of the Common Stock of GSI issuable or
issued upon conversion of the Series B Preferred Stock and the Series M
Preferred Stock.

         D. The Company and a majority of the shares of the Common Stock of GSI
issuable or issued upon conversion of the Series B Preferred Stock and the
Series M Preferred Stock have consented in writing to amend Sections 8.1 and 8.2
of the Agreement to provide for and accommodate certain rights, privileges and
restrictions with respect to the Warrants.

         NOW, THEREFORE, for and in consideration of the foregoing Recitals and
other good and valuable consideration, the receipt and adequacy of which are
hereby acknowledged, the Agreement is hereby amended as follows:

         SECTION 8.1 (F) IN THE FORM SET FORTH BELOW IS HEREBY ADDED TO SECTION
8.1:

                  "(f) The term "Warrantholders" means, collectively, those
persons who are the record owners of the warrants issued on April 23, 1999, by
the Company to certain purchasers pursuant to a Business Loan Agreement dated
April 23, 1999, by and between the Company and such purchasers (the "Loan
Agreement"), and any and all additional warrants issued thereafter pursuant to
the terms and provisions of the Loan Agreement or such warrants."

<PAGE>   32

         SECTION 8.2 IS HEREBY DELETED IN ITS ENTIRETY AND REPLACED WITH THE
FOLLOWING SECTION 8.2:

                  "8.2 Company Registration.

                  (a) Subject to Section 8.2(b) below, if (but without any
         obligation to do so) the Company proposes to register any of its stock
         or other securities under the Act in connection with the public
         offering of such securities solely for cash (other than a registration
         relating solely to the sale of securities to participants in a Company
         stock plan, or a registration on any form which does not include
         substantially the same information as would be required to be included
         in a registration statement covering the sale of the Registrable
         Securities or a SEC Rule 145 transaction), the Company shall, at such
         time, promptly give each Holder written notice of such registration.
         Upon the written request of each Holder given within fifteen (15) days
         after mailing of such notice by the Company in accordance with Section
         10.5, the Company shall, subject to the provisions of Sections 8.4,
         8.5, 8.6 and 8.7, cause to be registered under the Act all of the
         Registrable Securities that each such Holder has requested to be
         registered. Notwithstanding the foregoing, after the Company's initial
         public offering, the Company will not be required to give notice to the
         Holders of Registrable Securities if the underwriters managing the
         proposed offering have advised the Company in writing that in their
         judgment market conditions will not allow the inclusion of any
         secondary shares in such offering. If the managing underwriters and the
         Company subsequently determine to add any secondary shares in the
         offering, such notice shall be provided, and each Holder shall have the
         registration rights provided in this Section 8.

                  (b) The registration rights of the Holders pursuant to Section
         8.2(a) above are subject to the demand registration rights of the
         Warrantholders, as more particularly described in the Registration
         Rights Agreement dated April 23, 1999, by and between the Company and
         the Warrantholders. The Company shall notify the Holders of any such
         registration unless the underwriters managing the proposed offering
         have advised the Company in writing that the inclusion of Registrable
         Securities in such registration will reduce the amount of shares of
         Common Stock requested by the Warrantholders to be included in such
         registration. The Company shall be required to include the Registrable
         Securities in any such demand registration only to the extent that such
         inclusion will not reduce the amount of shares of Common Stock
         requested by the Warrantholders to be included in the registration.
         Thereafter, to the extent that the total amount of Registrable
         Securities requested by the Holders to be included in such offering
         exceeds the amount of securities that the underwriters determine may be
         included in the offering, the Registrable Securities will be
         apportioned among the Holders according to the total amount of
         securities owned by each Holder or in such other proportions as shall
         mutually be agreed to by such Holders.

         Except as expressly set forth in this Amendment, the Agreement shall
remain in full force and effect as executed and is hereby ratified and
confirmed. If there is any inconsistency or

<PAGE>   33

conflict between this Amendment and the Agreement, the provisions of this
Amendment shall govern and control.

         This Amendment may be executed in any number of counterparts, each of
which shall be deemed an original, but all of which together shall constitute
one and the same instrument. Copies (facsimile, photostatic or otherwise) of
signatures to this Amendment shall be deemed to be originals and may be relied
on to the same extent as the originals.

         This Amendment shall be binding upon, and shall inure to the benefit
of, the parties hereto and their respective successors and assigns.

         IN WITNESS WHEREOF, the Company has caused this Amendment to be
executed by its authorized representative as of the day and year first above
written.

                                  GENOMIC SOLUTIONS INC.

                                  By: /s/ Jeffrey S. Williams
                                     --------------------------------------
                                              Jeffrey S. Williams
                                  Its:        President and
                                              Chief Executive Officer<PAGE>   1
                                                                     EXHIBIT 4.4

                            B.I. SYSTEMS CORPORATION

                  SERIES M PREFERRED STOCK PURCHASE AGREEMENT

                            Dated as of May 7, 1997

<PAGE>   2

<TABLE>
<CAPTION>
                               TABLE OF CONTENTS

                                                                                Page
                                                                                ----

<S>                                                                             <C>
SECTION 1 AUTHORIZATION AND SALE ............................................... 1
     1.1 Authorization of the Series M Preferred Stock ......................... 1
     1.2 Purchase and Sale of Series M Preferred Stock ......................... 1

SECTION 2 CLOSING DATE; DELIVERY ............................................... 1
     2.1 Closing Date........................................................... 1
     2.2 Delivery............................................................... 1

SECTION 3 REPRESENTATIONS AND WARRANTIES OF THE COMPANY ........................ 1
     3.1 Organization and Standing; Charter and By-laws......................... 2
     3.2 Capitalization......................................................... 2
     3.3 Corporate Power; Authorization......................................... 2
     3.4 Validity of Securities................................................. 3
     3.5 Litigation............................................................. 3
     3.6 Employee Benefit Plans................................................. 3

SECTION 4 REPRESENTATIONS, WARRANTIES OF THE PURCHASER
          AND RESTRICTIONS ON TRANSFER IMPOSED BY THE ACT....................... 3
     4.1 Representations and Warranties......................................... 3
         4.1.1 Authorization.................................................... 3
         4.1.2 Investment ...................................................... 4
         4.1.3 Federal Securities Law .......................................... 4
     4.2 Transfer of Securities ................................................ 4
         4.2.1 Legend .......................................................... 5
         4.2.2 Restrictions on Transfer......................................... 5
         4.2.3 Termination of Restrictions and Removal of Legend................ 6

SECTION 5 CONDITIONS TO OBLIGATIONS OF THE PURCHASER ........................... 6
     5.1  Representations and Warranties Correct; Performance of Obligations.... 6
     5.2  Consents and Waivers.................................................. 6
     5.3  Certificate of Incorporation.......................................... 6
     5.4  Minimum Proceeds...................................................... 6
     5.5  Recapitalization...................................................... 7

SECTION 6 CONDITIONS TO OBLIGATIONS OF THE COMPANY ............................. 7

SECTION 7 RIGHT OF FIRST OFFER AND COVENANTS OF THE COMPANY..................... 7
     7.1  Right of First Offer.................................................. 7
     7.2  Covenants............................................................. 9
     7.3  Termination........................................................... 9
     7.4  Right of First Refusal on the Purchaser's Shares......................10
</TABLE>

                                       i
<PAGE>   3

<TABLE>
<CAPTION>
                                                                                     Page
                                                                                     ----

<S>                                                                                   <C>

SECTION 8 REGISTRATION RIGHTS......................................................... 11
     8.1  Definitions................................................................. 11
     8.2  Company Registration........................................................ 12
     8.3  Demand Registration......................................................... 12
     8.4  Obligations of the Company.................................................. 13
     8.5  Furnish Information......................................................... 14
     8.6  Underwriting Requirements................................................... 14
     8.7  Delay of Registration....................................................... 14
     8.8  Indemnification ............................................................ 14
     8.9  Reports Under Securities Exchange Act of 1934............................... 16
     8.10 Form S-3 Registration....................................................... 17
     8.11 Expenses of Registration.................................................... 17
     8.12 Assignment of Registration Rights........................................... 18
     8.13 "Market Stand-Off" Agreement................................................ 18
     8.14 Limitations on Subsequent Registration Rights............................... 18
     8.15 Amendment of Registration Rights............................................ 18
     8.16 Termination................................................................. 18

SECTION 9 MISCELLANEOUS............................................................... 19
     9.1  Waivers and Amendments...................................................... 19
     9.2  Governing Law............................................................... 19
     9.3  Successors and Assigns...................................................... 19
     9.4  Entire Agreement............................................................ 19
     9.5  Notices, Etc................................................................ 20
     9.6  Delays or Omissions......................................................... 20
     9.7  Severability................................................................ 20
     9.8  Titles and Subtitles........................................................ 20
     9.9  Counterparts................................................................ 20
     9.10 Expenses.................................................................... 20
</TABLE>

EXHIBITS

     A.   Form of Amended and Restated Certificate of Incorporation

     B.   Termination and Release Agreement

     C.   Description of Recapitalization

SCHEDULE

     4.1.3     Definition of Accredited Investor

                                       ii
<PAGE>   4

SERIES M PREFERRED STOCK PURCHASE AGREEMENT

THIS SERIES M PREFERRED STOCK PURCHASE AGREEMENT (this "Agreement") is dated as
of the 7th day of May, 1997 by and among B.I. Systems Corporation, a Delaware
corporation (the "Company"), and Millipore Corporation, a Massachusetts
corporation (the "Purchaser").

SECTION 1
AUTHORIZATION AND SALE

1.1 Authorization of the Series M Preferred Stock. The Company has authorized
the sale and issuance of up to 50,000 shares of its Series M Preferred Stock
(the "Series M Shares") to the Purchaser. The Series M Shares shall have the
rights, privileges and preferences set forth in the Company's Amended and
Restated Certificate of Incorporation attached as Exhibit A hereto (the
"Certificate of Incorporation").

1.2 Purchase and Sale of Series M Preferred Stock. Subject to the terms and
conditions hereof and in reliance upon the representations, warranties and
agreements contained herein, the Company agrees to issue and sell to the
Purchaser, and the Purchaser agrees to purchase from the Company, 50,000 Series
M Shares in consideration for the termination of the Note and related Security
Agreement, as such terms are defined in the Termination and Release Agreement
attached hereto as Exhibit B (the "Release Agreement").

SECTION 2
CLOSING DATE; DELIVERY

2.1 Closing Date. The purchase and sale of the Series M Shares hereunder
shall occur at a closing (the "Closing") to be held at Mackowski & Shepler, 343
Sansome Street, Suite 1215, San Francisco, California, on May 9, 1997 or at such
other time and place as shall be mutually agreed upon by the Company and the
Purchaser (the "Closing Date").

   2.2 Delivery. Subject to the terms of this Agreement, at the Closing, the
Company will deliver to the Purchaser a certificate representing 50,000 Series M
Shares registered in the Purchaser's name.

SECTION 3
REPRESENTATIONS AND WARRANTIES OF THE COMPANY

Except as otherwise expressly indicated in the Schedules attached hereto, the
Company hereby represents and warrants to the Purchaser as follows:
<PAGE>   5

3.1 Organization and Standing: Charter and By-laws. The Company is a corporation
duly organized, validly existing and in good standing under the laws of the
State of Delaware, and the company is authorized to exercise all of its
corporate powers, rights and privileges. True and accurate copies of the
Certificate of Incorporation and the by-laws of the Company, each as it will be
in effect at the Closing, have been delivered to the Purchaser.

3.2 Capitalization. The authorized capital Stock of the Company on the date of
the Closing will consist of 15,000,000 shares of $.001 par value common stock
("Common Stock") and 4,000,000 shares of $.001 par value Preferred Stock (The
"Preferred Stock"), 2,000,000 of which have been designated Series B Preferred
Stock (The "Series B Shares") and 50,000 of which have been designated Series M
Preferred Stock. Assuming the completion of the recapitalization described in
Exhibit C attached hereto (the "Recapitalization"), no Preferred Stock will be
outstanding at the date of the Closing. The Series M Shares will have the
rights,  preferences  and  privileges  set forth in the  Certificate of
Incorporation. Upon completion of the Recapitalization, there will be 31,280
shares of Common Stock issued and outstanding. The Company has reserved
6,060,000 shares of Common Stock for issuance upon conversion of the Series B
Preferred Stock, 270,027 shares of Common Stock for issuance upon conversion of
the Series M Preferred Stock and 1,590,000 shares of Common Stock for issuance
to employees, consultants and directors under its 1994 Omnibus Equity Incentive
Plan (the "Stock Plan") pursuant to which, prior to the Recapitalization,
options to acquire an aggregate of 194,500 shares were outstanding. The Company
intends to offer the holders of such options the right to exchange their
existing options for new options which, upon completion of the Recapitalization,
will entitle them to acquire the number of shares of Common Stock specified in
their existing option agreement, but at an exercise price of $0.33 per share.
The Stock Plan was adopted by the Board of Directors and stockholders of the
Company in July 1994 and amended in April 1997. Except as set forth herein or as
described in the description of the Recapitalization and except for the proposed
sale of Series B Preferred Stock, there are no outstanding rights, options,
warrants, preemptive rights, conversion rights or agreements for the purchase,
acquisition or receipt from the Company of any shares of capital stock or any
other securities of the Company. The Company is not a party to any existing
agreement with any person or entity which requires the Company to purchase from
such person or entity any of its capital stock, any securities convertible into
or exchangeable or exercisable for any of its capital stock, or any right,
options or warrants for its capital stock. All outstanding securities of the
Company, including the Series M Shares, have been issued in accordance with all
applicable state and federal securities laws.

3.3 Corporate Power; Authorization. The Company has all requisite legal and
corporate power to enter into this Agreement, to issue and sell the Series M
Shares as provided hereunder, and to carry out and perform its obligations under
the terms of this Agreement. All corporate action on the part of the Company and
its  officers,  directors  and  stockholders  that is necessary for the
authorization, execution and delivery of this Agreement by the Company, for the
performance of the Company's obligations hereunder and for the issuance and
delivery of the Series M Shares has been taken; and this Agreement constitutes a
legal and binding obligation of the Company, enforceable against the Company in

                                       2
<PAGE>   6

accordance with its terms, subject to: (i) judicial principles respecting or
limiting the availability of specific performance, injunctive relief and other
equitable remedies; and (ii) bankruptcy, insolvency, reorganization, moratorium
or other similar laws now or hereafter in effect generally relating to or
affecting creditors' rights.

   3.4 Validity of Securities. The Series M Shares, when issued, sold and
delivered in accordance with the terms of this Agreement, will be duly and
validly issued, fully paid and nonassessable and will be free and clear of any
liens, encumbrances or restrictions of any kind; provided, however, that the
Series M Shares may be subject to restrictions on transfer under state and
federal securities laws. The Common Stock issuable upon conversion of the Series
M Shares has been duly and validly reserved and, upon issuance in accordance
with the terms of this Agreement and the Certificate of Incorporation, will be
duly and validly issued, fully paid and nonassessable and will be free and
clear of any liens, encumbrances or restrictions of any kind; provided, however,
that the Common Stock may be subject to restrictions on transfer under state and
federal securities laws.

   3.5 Litigation. There is no action, suit or proceeding pending or, to the
knowledge of the Company, threatened against the Company or related to the
business conducted by the Company. The Company is not a party or subject to the
provisions of any order, writ, injunction, judgment or decree of any court or
government agency or instrumentality. There is no action, suit, proceeding or
investigation by the Company currently pending or which the Company intends to
initiate.

   3.6 Employee Benefit Plans. Except for the Company's 401(k) Plan, short-term
and long-term disability plans, prescription drug plans, and medical, dental and
life insurance plans, the Company does not have any Employee Benefit Plan as
defined in the Employee Retirement Income Security Act of 1974.

                                   SECTION 4
                  REPRESENTATIONS, WARRANTIES OF THE PURCHASER
                AND RESTRICTIONS ON TRANSFER IMPOSED BY THE ACT

   4.1 Representations and Warranties. The Purchaser hereby represents and
warrants to the Company as follows:

     4. 1.1 Authorization. (a) All action on the part of the Purchaser
necessary for the execution, delivery and performance of this Agreement, and the
consummation of the transactions contemplated hereby has been taken and,
assuming due execution and delivery by the Company, this Agreement constitutes a
legal, valid, binding and enforceable obligation of the Purchaser, subject to:
(i) judicial principles respecting or limiting the availability of specific
performance,  injunctive relief, and other equitable remedies;  and (ii)
bankruptcy, insolvency, reorganization, moratorium or other similar laws now or
hereafter in effect generally relating to or affecting creditors' rights.

                                       3
<PAGE>   7

          (b) The Purchaser  represents  and warrants that: (i) the Purchaser is
an existing entity, and has not been organized or reorganized for the purpose of
making this  investment,  (ii) the undersigned has the authority to execute this
Agreement and any other documents in connection with an investment in the Series
M Shares on the Purchaser's behalf, and (iii) the Purchaser has the power, right
and  authority to invest in the Series M Shares and enter into the  transactions
contemplated  hereby,  and the  investment is suitable and  appropriate  for the
Purchaser (given the risks and illiquid nature of the investment).

          4.1.2 Investment.

          (a) The  Purchaser  has been advised that the Series M Shares have not
been  registered  under the Securities  Act of 1933, as amended (the "Act"),  or
registered or qualified under any applicable state securities laws on the ground
that no  distribution  or  public  offering  of the  Series  M  Shares  is to be
effected,  and that in this  connection  the  Company  is relying in part on the
representations of the Purchaser set forth in this Section 4;

          (b) The Purchaser  has been further  advised that no public market now
exists for any of the securities  issued by the Company and that a public market
may never exist for the Series M Shares;

          (c) The  Purchaser  is  purchasing  the  Series M  Shares  for its own
account and not for any other person;

          (d) By reason of its business or financial  experience,  the Purchaser
has the capacity to protect its own interest in connection with the transactions
contemplated  hereunder,  is able to bear  the  risks  of an  investment  in the
Company, and could afford a complete loss of such investment;

          (e) The  Purchaser  is aware of the  Company's  business  affairs  and
financial condition and has acquired sufficient information about the Company to
reach an informed and knowledgeable decision to acquire the Series M Shares; and

          (f) The Purchaser has had the  opportunity to ask questions  regarding
the  Company  and the  Company  has  provided  information  in  response  to the
questions.

          4.1.3  Federal  Securities  Law.  In order to enable  the  Company  to
determine  whether the sale of the Series M Shares is exempt  from  registration
under the Act, such Purchaser  represents that it is an Accredited  Investor (as
defined in Schedule  4.1.3  hereof) and is acquiring the Series M Shares for its
own account,  for investment,  and not with a view to, or for sale in connection
with, any distribution thereof.

       4.2 Transfer of Securities. Neither the Series M Shares nor the shares of
Common  Stock issuable  upon  conversion  of the  Series  M  Shares  shall  be
transferable  except upon the  conditions  specified in this Section 4.2,  which
conditions are intended to insure compliance with the provisions of the Act with
respect to the transfer of such securities.

                                       4
<PAGE>   8

     4.2.1 Legend. Unless and until otherwise permitted by this Section
4.2, each certificate representing (i) the Series M Shares or (ii) the Company's
Common Stock issued upon conversion of the Series M Shares, will be endorsed
with a legend substantially in the following form:

        "THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
          ACT OF 1933, AS AMENDED, OR ANY APPLICABLE STATE SECURITIES
          LAWS, AND MAY NOT BE SOLD, PLEDGED OR OTHERWISE TRANSFERRED
        UNLESS, (A) COVERED BY AN EFFECTIVE REGISTRATION STATEMENT UNDER
        THE SECURITIES ACT OF 1933, AS AMENDED, AND ANY APPLICABLE STATE
         SECURITIES LAWS, OR (B) THE COMPANY HAS BEEN FURNISHED WITH AN
        OPINION OF COUNSEL ACCEPTABLE TO THE COMPANY TO THE EFFECT THAT
         SUCH SALE, PLEDGE OR TRANSFER IS EXEMPT FROM THE REGISTRATION
        AND PROSPECTUS DELIVERY REQUIREMENTS OF SAID SECURITIES ACT AND
                     ANY APPLICABLE STATE SECURITIES LAWS."

     4.2.2 Restrictions on Transfer. The Series M Shares and the Common
Stock issuable upon the conversion of the Series M Shares shall not be sold,
assigned, pledged or transferred, and the Company shall not be required to
register any such sale, assignment, pledge or transfer, unless and until one of
the following events shall have occurred:

     (a) the Company shall have received an opinion of counsel, in form and
substance reasonably acceptable to the Company and its counsel, stating that the
contemplated transfer is exempt from registration under the Act as then in
effect, and the Rules and Regulations of the Securities and Exchange Commission
(the "Commission") thereunder and any applicable state securities laws;

     (b) the Company shall have been furnished with a letter from the
Commission in response to a written request in form and substance acceptable to
counsel for the Company setting forth all of the facts and circumstances
surrounding the contemplated sale, assignment, pledge or transfer, stating that
the Commission will take no action with regard to the contemplated sale,
assignment, pledge or transfer; or

     (c) the Series M Shares, or the Common Stock issuable upon conversion
of the Series M Shares, are transferred pursuant to a registration statement
which has been filed with the Commission and has become effective.

Within five business days after delivery to the Company and its counsel
of an opinion described in clause (a) above, the Company either shall deliver to
the proposed transferor a statement to the effect that such opinion is not
satisfactory in the reasonable opinion of its counsel (and shall specify in
detail the legal analysis supporting any such

                                       5
<PAGE>   9

conclusion) or shall authorize the Company's transfer agent to make the
requested transfer.

     4.2.3  Termination of Restrictions and Removal of Legend.  The
restrictions on transfer imposed by this Section 4.2 shall cease and terminate
as to the Series M Shares and the Common Stock issuable upon conversion of the
Series M Shares, when (i) such securities (as applicable) shall have been
effectively registered under the Act and sold by the holder thereof in
accordance with such registration, or (ii) an acceptable opinion as described in
Section 4.2.2(a) or a "no action" letter described in Section 4.2.2(b) states
that all future transfers of such securities by the TRANSFEROR OR THE
CONTEMPLATED transferee would be exempt from registration under the Act. When
the restrictions on transfer contained in this Section 4.2 have terminated as
provided above, the holder of the securities as to which such restrictions shall
have terminated or the transferee of such holder shall be entitled to receive
promptly from the Company, without expense to him, new certificates not bearing
the legends set forth in Section 4.2.1 hereof.

                                   SECTION 5
                   CONDITIONS TO OBLIGATIONS OF THE PURCHASER

    The obligation of the Purchaser to purchase the Series M Shares at the
Closing is subject to each of the following conditions having been fulfilled on
or prior to the Closing Date or waived by the Purchaser in accordance with the
provisions of Section 9.1 hereof:

    5.1  Representations and Warranties Correct; Performance of Obligations.
The representations and warranties made by the Company in Section 3 hereof shall
be true and correct when made, and shall be true and correct on the Closing Date
with the same force and effect as if they had been made on and as of the Closing
Date; and the Company shall have performed all obligations and conditions herein
required to be performed or observed by it on or prior to the Closing Date.

    5.2  Consents and Waivers. The Company shall have obtained any and all
consents, permits and waivers and made all filings necessary or appropriate for
consummation of the transactions contemplated by this Agreement.

    5.3  Certificate of Incorporation. The Certificate of Incorporation
shall have been filed with the Secretary of State of the State of Delaware.

    5.4  Minimum Proceeds. The Company shall have raised at least $850,000
pursuant to its proposed sale of the Series B Shares.

                                       6
<PAGE>   10

       5.5 Recapitalization. The Recapitalization shall have been completed such
that immediately prior to or simultaneously with the Closing the Company shall
have no outstanding Series A Preferred Stock and the Company shall have no
further obligations pursuant to its 15.0% Subordinated Debentures or the
promissory note issued to Millipore Corporation.

                                    SECTION 6
                    CONDITIONS TO OBLIGATIONS OF THE COMPANY

       The Company's obligation to issue, sell and deliver the series M Shares
at the Closing is subject to the following conditions having been fulfilled on
or prior to the Closing Date or waived by the Company in accordance with the
provisions of Section 9.1 hereof: The representations and warranties made by the
Purchaser in Section 4 hereof shall be true and correct when made, and shall be
true and correct on the Closing Date with the same force and effect as if they
had been made on and as of the Closing Date, the conditions set forth in
Sections 5.2, 5.3, 5.4 and 5.5 hereof shall have been satisfied and the
Purchaser shall have executed and delivered to the Company the Release Agreement
substantially in the form of Exhibit B attached thereto and shall have complied
with all of the terms of the Release Agreement.

                                    SECTION 7
                RIGHT OF FIRST OFFER AND COVENANTS OF THE COMPANY

       7.1 Right of First Offer.

          (a)  Subject to the terms and conditions specified in this Section 7.
1, the Company hereby grants to the Purchaser a right to participate in future
sales by the Company of its Shares (as hereinafter defined).

          (b)  Each time the Company proposes to offer any shares of, or
securities convertible into or exercisable for any shares of, any class of its
capital stock ("Shares"), the Company shall first make an offering of a portion
of such Shares (as determined in subsection (2) below) to the Purchaser in
accordance with the following provisions:

                   (1) The Company shall deliver a written notice ("Notice") to
              the Purchaser stating (i) its bona fide intention to offer such
              Shares, (ii) the number of such Shares to be offered, and (iii)
              the price and terms, if any, upon which it proposes to offer such
              Shares.

                   (2) Within 10 calendar days after receipt of the Notice, the
              Purchaser may elect to purchase or obtain, at the price and on the
              terms specified in the Notice, up to that portion of such Shares
              which equals the proportion that the number of shares of Common
              Stock

                                       7
<PAGE>   11

       held by such Purchaser (including for such calculation any shares
       issuable upon conversion of any capital stock convertible into
       Common Stock) bears to the total number of shares of Common Stock
       of the Company then outstanding held by the Purchaser and all
       other persons who have been granted a right of first offer
       (assuming for such calculation any shares issuable upon conversion
       of any capital stock convertible into common stock).

          (3) The Company may during the 10-day period following the
       expiration of the 10-day period provided in subsection (2)
       hereof, offer the remaining unsubscribed portion of such Shares
       which the Purchaser has not elected to purchase to any person or
       persons at a price not less than, and upon terms no more favorable
       to the offeree than those specified in the Notice. If the Company
       does not enter into an agreement for the sale of the Shares within
       90 days of the expiration of such 10-day period, or if such
       agreement is not consummated within 120 days following the
       expiration of such 10-day period, the right provided hereunder
       shall be deemed to be revived and such Shares shall not be offered
       unless first reoffered to the Purchaser in accordance herewith.

          (4) The right of first offer in this Section 7. 1 shall not
       be applicable (i) to the issuance or sale of shares of Common
       Stock (as adjusted to reflect any stock splits, combinations or
       other events involving the Common Stock) to employees, consultants
       or members of the Board of Directors pursuant to employee or
       director stock plans which are approved in writing by the
       Company's Board of Directors, (ii) to the Public Offering (as
       defined in Section 7.3 hereof) or to any offering of Shares after
       consummation of the Public Offering, (iii) to the issuance of
       securities pursuant to the conversion or exercise of presently
       outstanding convertible or exercisable securities, (iv) to any
       Common Stock issued upon conversion of the Series B Preferred
       Stock, the Series M Preferred Stock or other series of Preferred
       Stock issued pursuant to the Certificate of Incorporation, (v) to
       securities issued in connection with any acquisition or business
       combination transaction approved by the Board of Directors of the
       Company, or (vi) to securities issued in connection with equipment
       lease financings or other financings with commercial lenders or in
       strategic transactions involving, the Company and other entities
       including joint ventures or marketing, distribution or development
       arrangements, in each case provided that any issuance pursuant to
       subsection (vi) has been approved by the Board of Directors of the
       Company.

                                       8
<PAGE>   12

          7.2 Covenants.

              (a) Taxes.  The Company will promptly pay and discharge,  or cause
to be paid and discharged,  when due and payable, all lawful taxes, assessments,
and governmental charges or levies imposed upon the income,  profits,  property,
or business of the Company;  provided,  however,  that any such tax, assessment,
charge,  or levy need not be paid if the  validity  thereof  shall  currently be
contested in good faith by appropriate proceedings and if the Company shall have
set aside on its books adequate reserves with respect thereof.

              (b) Maintain  Properties.  The company will keep its properties in
good repair,  working order,  and condition,  reasonable wear and tear excepted,
and from time to time will make all  necessary  and  proper  repairs,  renewals,
replacements, additions, and improvements thereto.

              (c) Maintain  Corporate  Existence.  The Company shall maintain in
full force and effect its corporate  existence,  rights,  and franchises and all
material  licenses  and  other  material  rights  to  use  processes,  licenses,
trademarks,  trade names,  or copyrights  owned or possessed by it and deemed by
the Company to be necessary to the conduct of its business.

              (d)  Insurance.  The Company will maintain  insurance of the types
and in the amounts generally deemed adequate for its business.

              (e) Limit on Expenditures. Without the approval in writing, of the
Company's Board of Directors, the Company will not make or incur any expenditure
(including,   without  limitation,   capital   expenditures,   acquisitions  and
capitalized  leases)  or  guarantee,  assume or  otherwise  become  directly  or
indirectly  liable for any indebtedness  (including  capitalized  leases) which,
individually  or  in  combination  with  related  expenditures,   guarantees  or
assumptions subject to a common commitment, exceed $250,000.

              (f) Financial  Information.  As long as the Purchaser continues to
hold Series M Shares or Common Stock issued upon conversion thereof, the Company
shall  deliver as soon as  practicable  (i) after the end of each fiscal year of
the Company,  and in any event with 90 days thereafter,  an audited consolidated
balance sheet of the Company as of the end of such year and audited consolidated
statements of income,  stockholders'  equity and cash flows for such year, which
year-end  financial  reports  shall be prepared  in  accordance  with  generally
accepted accounting principles and (ii) after the end of each of the first three
fiscal  quarters of each year,  and in any event within 45 days after the end of
each such  fiscal  quarter,  unaudited  quarterly  financial  statements,  which
quarterly  statements  shall be prepared in accordance  with generally  accepted
accounting principles.

          7.3 Termination. The right of first offer set forth in Section 7.1 and
the covenants set forth in Section 7.2 hereof shall  terminate  upon the earlier
to occur  of (i) the  closing  of a public  offering  pursuant  to an  effective
registration statement under the

                                       9
<PAGE>   13

Securities Act of 1933, as amended, covering the offer and sale of the
Company's Common Stock where the gross proceeds to the Company are not
less than $7,500,000, where the public offering price is not less than $0.75
per share (adjusted to reflect any stock splits, combinations or similar events
after the date hereof) and which results in the Company's Common Stock being
traded on an exchange or quoted on the National Association of Securities
Dealers, Inc. Automated quotation ("NASDAQ") or quoted on the NASDAQ National
Market System (the "Public Offering") and (ii) the closing of the Company's
sale of all or substantially all of its assets or the acquisition of the
Company by another entity by means of merger or consolidation resulting in the
exchange of the outstanding  shares of the Company's capital  stock for
securities or consideration issued, or caused to be issued, by the acquiring
entity or its subsidiary.

     7.4 Right of First Refusal on the Purchaser's Shares.

       7.4.1 If the Purchaser wishes to transfer any securities of the
Company issued to such person at any time except in a Permitted Transfer, the
Purchaser shall do so only for cash,  unsecured promissory notes, cash
equivalents, or a combination of the foregoing, and shall first give written
notice (the "Offer Notice") to the Company, identifying the securities proposed
to be transferred (the "Offered  Securities"),  identifying the proposed
transferee, and stating the price at which, and other material terms on which,
the Purchaser wishes to transfer the Offered Securities, including the date of
the proposed transfer.

       7.4.2 Delivery of an Offer Notice to the Company shall constitute
an offer to transfer the Offered Securities, in whole but not in part (the
"Offer"), to the Company pursuant to this Section 7.4, at the price and on the
other material terms described in the Offer Notice.

       7.4.3 The Company may elect, by written notice delivered to the
Purchaser not later than fourteen calendar days after the Company receives the
Offer Notice, to accept the Offer with respect to all of the Offered Securities.

       7.4.4 If the Company elects to accept an Offer in its entirety,
then the Purchaser shall transfer the Offered Securities to the Company and the
Company shall acquire the Offered Securities, at the price and on the other
material terms described in the Offer Notice. The consummation of the transfer
shall take place at the chief executive offices of the Company, on the date
specified for the proposed transfer in the Offer Notice (but not earlier than
thirty-four calendar days after the Company shall have received the Offer
Notice), or at such other location or date on which the participants in the
transaction agree in writing.

       7.4.5 If the Company does not accept an Offer in its entirety,
then the Purchaser may transfer the Offered Securities (subject to the
provisions of this Agreement other than this Section 7.4 and to any other
agreements binding on the Purchaser) to the transferee named in the Offer
Notice, at any time within the period of ninety calendar days beginning on the
date the Company received the Offer Notice. The

                                       10
<PAGE>   14

provisions  of this  Section 7.4 shall  again  apply to any  transfer of Offered
Securities not transferred within such period.

              7.4.6 A  "Permitted  Transfer"  is a transfer of  securities  to a
Permitted  Transferee  if,  prior  to  the  consummation  of the  transfer,  the
Permitted Transferee shall have agreed in writing to be bound as a party to this
Agreement by all the terms of this  Agreement  applicable  to the  Purchaser.  A
"Permitted Transferee" means any of:

                   (a) the spouse or a lineal  ancestor or  descendant  (whether
              natural or adopted) of the transferor;

                   (b) a trust all the beneficiaries (primary and contingent) of
              which are either the transferor or the spouse or a lineal ancestor
              or descendant (natural or adopted) of the transferor; or

                   (c) a partner in a transferor  which is a  partnership,  or a
              stockholder of a transferor which is a limited liability  company,
              which person receives the transfer as part of a distribution among
              partners,  stockholders,  or  members,  as the case may be, of the
              transferor.

                                    SECTION 8
                               REGISTRATION RIGHTS

              The Company covenants and agrees as follows:

              8.1 Definitions. For purposes of this Section 8:

                   (a) The term  "register",  "registered,"  and  "registration"
refer  to a  registration  effected  by  preparing  and  filing  a  registration
statement or similar document in compliance with the Act, and the declaration or
ordering of effectiveness of such registration statement or document;

                   (b) The term  "Registrable  Securities"  means (i) the Common
Stock issuable or issued upon  conversion of the Series B Preferred Stock or the
Series M Preferred  Stock 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 Series B Preferred  Stock or Series M
Preferred Stock, other Preferred Stock or Common Stock; provided,  however, that
Common Stock or other securities shall only be treated as Registrable Securities
if and so long as (1) they have not been  sold to or  through a broker or dealer
or underwriter in a public distribution or a public securities transaction,  and
(2) they have not been sold in a transaction exempt from the  registration and
prospectus  delivery  requirements of the Act under Section 4(1) thereof so that
all transfer restrictions

                                       11
<PAGE>   15

and restrictive legends with respect thereto are removed upon the consummation
of such sale;

          (c) The number of shares of "Registrable Securities then outstanding"
shall be determined by the number of shares of Common Stock outstanding which
are, and the number of shares of Common Stock issuable pursuant to then
exercisable or convertible securities which are, Registrable Securities;

          (d) The term "Holder" means any person who is the record owner of
Registrable Securities, the Series B Shares Or the Series M Shares, or any
assignee thereof in accordance with Section 8.12 hereof; and

          (e) The term "SEC" means the  Securities and Exchange Commission or
any other federal agency at the time administering the Act.

       8.2 Company Registration. If (but without any obligation to do so) the
Company proposes to register any of its stock or other securities under the Act
in connection with the public offering of such securities solely for cash (other
than a registration relating solely to the sale of securities to participants in
a Company stock plan, or a registration on any form which does not include
substantially the same information as would be required to be included in a
registration statement covering the sale of the Registrable Securities or a SEC
Rule 145 transaction), the Company shall, at such time, promptly give each
Holder written notice of such registration. Upon the written request of each
Holder given within fifteen (15) days after mailing of such notice by the
Company in accordance with Section 9.5, the Company shall, subject to the
provisions of Sections 8.4, 8.5, 8.6 and 8.7, cause to be registered under the
Act all of the Registrable Securities that each such Holder has requested to be
registered. Notwithstanding the foregoing, after the Company's initial public
offering, the Company will not be required to give notice to the Holders of
Registrable Securities if the underwriters managing the proposed offering have
advised the Company in writing that in their judgment market conditions will not
allow the inclusion of any secondary shares in such offering. In the event the
managing underwriters and the Company subsequently determine to add any
secondary shares in the offering, such notice shall be provided, and each Holder
shall have the registration rights provided in this Section 8.

       8.3 Demand Registration. Subject to the terms of this Agreement, in the
event that the Company shall receive from the Holders of at least thirty percent
(30%) of the Registrable Securities then outstanding, at any time after six (6)
months after the effective date of the registration statement covering the
Company's initial public offering, a written notice that it or they intend to
offer or cause to be offered for public sale at least twenty-five percent (25 %)
of the Registrable Securities then outstanding (or any lesser percentage if the
aggregate offering price to the public is greater than $5,000,000), the Company
will so notify all Holders. Upon written request of any Holder given within
fifteen (15) days after the receipt by such Holder from the Company of such
notification, the Company will use its best efforts to cause such of the
Registrable Securities as may be requested by any Holder (including the Holder
giving the initial notice of intent to offer) to

                                       12
<PAGE>   16

be registered under the Securities Act as expeditiously as possible (a "Demand
Registration"). The Company shall not be required to effect more than one (1)
Demand Registration. If (i) in the good faith judgment of the Board of Directors
of the Company, a Demand Registration would be materially detrimental to the
Company and the Board of Directors of the Company concludes, as a result, that
it is essential to defer the filing of such registration statement at such time,
and (ii) the company shall furnish to each Holder 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 materially detrimental to the Company
for such registration statement to be filed in the near future, then the Company
shall have the right to defer such filing for the period during which such
Demand Registration would be materially detrimental, provided that the Company
may not defer the filing for a period of more than ninety (90) days after
receipt of the request for a Demand Registration, and more than once in any
12-month period.

       8.4 Obligations of the Company. Whenever required under Section 8.2 to
effect the registration of any Registrable Securities, 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 90 days or until all of the
securities registered thereunder are sold, whichever occurs sooner.

           (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
Act with respect to the disposition of all securities covered by such
registration statement.

           (c) Furnish to the Holders such numbers of copies of a prospectus,
including a preliminary prospectus,  in conformity with the requirements of the
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.

           (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 of such offering. Each Holder participating
in Such underwriting shall also enter into and perform its obligations under
such an agreement.

                                       13
<PAGE>   17

              (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 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  therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing.

          8.5  Furnish  Information.  It shall be a condition  precedent  to the
obligations  of the Company to take any action  pursuant to this  Section 8 with
respect to the  Registrable  Securities  of any selling  Holder that such Holder
shall furnish to the Company such information  regarding itself, the Registrable
Securities  held by it and the intended method of disposition of such securities
as shall be required to effect the  registration  of such  Holder's  Registrable
Securities.

8.6  Underwriting  Requirements.   In  connection  with  any  offering involving
an underwriting of shares of the Company's  capital stock, the Company shall
not be  required  under  Section  8.2  to  include  any  of the  Holders'
securities   in  such   underwriting   unless  they  accept  the  terms  of  the
underwriting as agreed upon between the Company and the  underwriters  selected
by the  persons  entitled  to  select  the  underwriters,  and then only in such
quantity  as the  underwriters  determine  in  their  sole  discretion  will not
jeopardize  the success of the offering by the  Company.  If the total amount of
securities,  including  Registrable  Securities,  requested  by  Holders  to be
included in such offering  exceeds the amount of  securities  sold other than by
the  Company  that the  underwriters  determine  in  their  sole  discretion  is
compatible with the success of the offering,  then the Company shall be required
to include  in the  offering  only that  number of such  securities,  including
Registrable   Securities,   which  the  underwriters  determine  in  their  sole
discretion  will not jeopardize  the success of the offering (the  securities so
included to be apportioned pro rata among all selling stockholders  according to
the total  amount of  securities  owned by each selling  stockholder  or in such
other proportions as shall mutually be agreed to by such selling  stockholders).
For purposes of the preceding parenthetical  concerning  apportionment,  for any
selling  stockholder which is a holder of Registrable  Securities and which is a
partnership or corporation, the partners, retired partners and stockholders 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  stockholder"  and any pro-rata
reduction  with respect to such "selling  stockholder"  shall be based upon the
aggregate amount of shares  owned by all  entities  and  individuals  included
in such  "selling stockholder," as defined in this sentence.

          8.7 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 Section 8.

          8.8  Indemnification.  In the event  any  Registrable  Securities  are
included in a registration statement under this Section 8:

                                       14
<PAGE>   18

   (a) To the extent permitted by law, tile Company will indemnify
and hold harmless each Holder, any underwriter (as defined in the Act) for such
Holder and each person, if any, who controls such Holder or underwriter within
the meaning of the 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 Act, or 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"): (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 therein 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 Act, the 1934 Act, any state securities law or any rule or
regulation promulgated under the Act, or the 1934 Act or any state securities
law; and the Company will pay to each such Holder, underwriter or controlling
person, as incurred, any legal or other expenses reasonably incurred by one law
firm retained by them (or such additional law firms retained by a Holder or
Holders if such Holder or Holders reasonably believe there exists a conflict of
interest among them) in connection with investigating or defending any such
loss, claim, damage, liability or action; provided, however, that the indemnity
agreement contained in this subsection 8.8(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 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 any such Holder, underwriter or controlling person.

   (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 has signed the registration statement, each person, if any, who
controls the Company within the meaning of the Act, any underwriter, any other
Holder selling securities in such registration statement and any controlling
person of any such underwriter or other Holder against any losses, claims,
damages or liabilities (joint or several) to which any of the foregoing persons
may become subject, under the Act, or 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 pay, as
incurred, any legal or other expenses reasonably incurred by any person intended
to be indemnified pursuant to this subsection 8.8(b), in connection with
investigating or defending any such loss, claim, damage, liability or action;
provided, however, that the indemnity agreement contained in this subsection
8.8(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; provided, that,
in no event shall any indemnity

        15
<PAGE>   19

under this subsection 8.8(b) exceed the net proceeds from the offering received
by such Holder.

              (c)  Promptly after receipt by an indemnified party under this
Section 8.8 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 8.8, 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
(together with all other indemnified parties which may be represented without
conflict by one counsel) shall have the right to retain one separate counsel,
with the fees and expenses to be paid by the indemnifying  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 prejudicial to its ability to defend such action, shall relieve such
indemnifying party of any liability to the indemnified party under this Section
8.8, but the failure to deliver written notice to the indemnifying party will
not relieve it of any liability that it may have to any indemnified party
otherwise than under this Section 8.8.

              (d)  The obligations of the Company and Holders under this Section
8.8 shall survive the completion of any offering of Registrable Securities in a
registration statement under this Section 8, and otherwise.

          8.9 Reports Under Securities Exchange Act of 1934. With a view to
making available to the Holders the benefits of Rule 144 promulgated under the
Act and any other rule or regulation of the SEC that may at any time permit a
Holder to sell securities of the Company to the public without registration, the
Company agrees to:

              (a)  make and keep public information available, as those terms
are understood and defined in SEC Rule 144, at all times after ninety (90) days
after the effective date of the first registration statement filed by the
Company for the offering of its securities to the general public;

              (b) file with the SEC in a timely manner all reports and other
documents required of the Company under the Act and the 1934 Act; and

              (c) furnish to any Holder, so long as the Holder owns any
Registrable Securities, forthwith upon request (i) a written statement by the
Company that it has complied with the reporting requirements of SEC Rule 144 (at
any time after ninety (90) days after the effective date of the first
registration statement filed by the Company), the Act and the 1934 Act (at any
time after it has become subject to such reporting requirements), (ii) a copy of
the most recent annual or quarterly report of the Company and

                                       16
<PAGE>   20

such other reports and documents so filed by the Company, and (iii) such other
information as may be reasonably requested in availing any Holder of any rule or
regulation of the SEC which permits the selling of any such securities without
registration or pursuant to such form.

         8.10 Form S-3 Registration. In case the Company shall receive from any
Holder or Holders of the Registrable Securities then Outstanding a written
request or requests that the Company effect a registration on Form S-3 for a
public offering the aggregate offering price of which would exceed $1,000,000,
the Company will:

              (a)  promptly give written notice of the proposed registration,
and any related qualification or compliance, to all other Holders; 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 Holder's or
Holders' Registrable Securities as are specified in such request, together with
all or such portion of the Registrable Securities of any other Holder or 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 8.10: (i) if
Form S-3 is not available for such offering by the Holders; (ii) if the Company
shall furnish to the Holders 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 detrimental to the Company and its stockholders 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 8.10; (iii) if the Company has, within
the twelve (12) month period preceding the date of such request, already
effected two registrations for the Holders pursuant to Section 8.2, 8.3 or this
Section 8.10; or (iv) 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
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.

         8.11 Expenses of Registration. The Company shall bear and pay all
expenses incurred in connection with any registration, filing or qualification
of Registrable Securities with respect to a total of three registrations,
whether pursuant to Section 8.2, 8.3 or 8.10 or a combination thereof, including
(without limitation) all registration, filing, and qualification fees, printers
and accounting fees relating or apportionable thereto and the fees and
disbursements of one counsel for the selling Holders selected by them (which the
Company may request be the Company's counsel if such counsel is reasonably
acceptable to

                                       17
<PAGE>   21

such selling Holders), but excluding underwriting discounts and commissions and
stock transfer taxes relating to Registrable Securities.

         8.12 Assignment of Registration Rights. The rights to cause the Company
to register Registrable Securities pursuant to this Section 8 may only be
assigned to a purchaser, assignee or transferee of the underlying Registrable
Securities.

         8.13 "Market Stand-Off' Agreement. Each Purchaser hereby agrees that
for a period of 180 days following the effective date of the first registration
statement of the Company covering common stock filed on Form S-1 under the Act
and for any registration effected pursuant to Sections 8.2, 8.3 or 8.10
(provided the Holders are given written notice of the offering at least fifteen
(15) days prior to the Company's filing with the SEC of a registration statement
relating thereto), it shall not, unless otherwise agreed by the Company and the
managing I underwriters, 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 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
Purchaser (and the shares or securities of every other person subject to the
foregoing restriction) until the end of such period.

         8.14 Limitations on Subsequent Registration Rights. From and after the
date of this Agreement, the Company shall not, without the prior written consent
of the Holders of a majority of the outstanding Registrable Securities, enter
into any agreement with any holder or prospective holder of any securities of
the Company which would allow such holder or prospective holder to include such
securities in any registration filed under Section 8.2, 8.3 or 8.10 hereof,
unless under the terms of such agreement, such holder or prospective holder may
include such securities in any such registration only to the extent that the
inclusion of his securities will not reduce the amount of the Registrable
Securities of the Holders which is included.

         8.15 Amendment of Registration Rights. Any provision of this Section 8
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 a majority of the Registrable
Securities then outstanding. Any amendment or waiver effected in accordance with
this paragraph shall be binding upon each holder of any Registrable Securities
then outstanding, each future holder of all such Registrable Securities, and the
Company.

         8.16 Termination. The rights provided in this Section 8 shall terminate
on the fifth anniversary of the closing of the Company's initial public offering
pursuant to

                                       18
<PAGE>   22

which the Company registers shares of Common Stock under the Act and following
shortly thereafter or concurrently therewith registers its Common Stock under
the 1934 Act.

                                   SECTION 9
                                 MISCELLANEOUS

         9.1 Waivers and Amendments. Except as to Section 8 in which case the
provisions of Section 8.15 shall apply, with the written consent of the record
or beneficial holders of more than 50% of the aggregate of (i) the then
outstanding number of shares of the Series M Shares (treated as if converted to
Common Stock) and (ii) all shares of Common Stock obtained upon conversion of
the Series M Shares, the obligations of the Company and the rights of the
holders of Series M Shares and the Common Stock obtained upon conversion of the
Series M Shares under this Agreement may be waived (either generally or in a
particular instance, either retroactively or prospectively and either for a
specified period of time or indefinitely), and with the same consent the
Company, when authorized by resolution of its board of directors, may enter into
a supplementary agreement for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Agreement;
provided, however, that no such waiver or supplemental agreement shall reduce
the aforesaid percentages which are required to consent to any waiver or
supplemental agreement, without the unanimous consent of the record or
beneficial holders of all of the then outstanding number of shares of the Series
M Shares or the shares of Common Stock obtained upon conversion of the Series M
Shares. Upon the effectuation of each such waiver, consent, agreement of
amendment or modification, the Company promptly shall give written notice
thereof to the record holders of the then outstanding Series M Shares and the
shares of Common Stock obtained upon conversion of the Series M Shares. This
Agreement or any provision hereof may not be changed, waived, discharged or
terminated orally, but only by a statement in writing signed by the party
against which enforcement of the change, waiver, discharge or termination is
sought, except to the extent provided in this Section 9.1; provided, however,
that the conditions to Closing contained in Section 5 of this Agreement may only
be waived by the Purchaser for itself.

         9.2 Governing Law. This Agreement shall be governed in all respect's by
the laws of the State of Delaware as such laws are applied to agreements between
Delaware residents entered into and to be performed entirely within Delaware.

         9.3 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.

         9.4 Entire Agreement. This Agreement and the other documents delivered
pursuant hereto constitute the full and entire understanding and agreement
between the parties with regard to the subjects hereof and thereof.

                                       19
<PAGE>   23
         9.5 Notices, Etc. All notices and other communications required or
permitted hereunder shall be in writing and shall be deemed effectively given
upon personal delivery or upon the seventh day following mailing by registered
air mail, postage prepaid, addressed (a) if to the Purchaser, as indicated on
the signature page hereto, or at such other address as it shall have furnished
to the Company, (b) if to the Company, to B.I. Systems Corporation, 525 Avis
Drive, Ann Arbor, Michigan, 48108, and addressed to the attention of the
corporate secretary, or at such other address as the Company shall have
furnished to the Purchaser, or (c) if to any other holder of the Series M Shares
or of Common Stock issued upon conversion of the Series M Shares at such address
as such holder shall have furnished to the Company in writing, or, until such
holder so furnishes an address to the Company, then to and at the address of the
last holder of such Series M Shares or shares of Common Stock issued upon
conversion of the Series M Shares, who so furnished an address to the Company.
In addition, any notice delivered to an address outside the United States shall
be duplicated by counterpart telex notice (if available).

         9.6 Delays or Omissions. No delay or omission to exercise any right,
power or remedy accruing to any holder of any securities issued or sold or to be
issued or sold hereunder, upon any breach or default of the Company under this
Agreement shall impair any such right, power or remedy of such holder nor shall
it be construed to be a waiver of any such breach or default, or an acquiescence
therein, or in any similar breach or default thereafter occurring, nor shall any
waiver of any single breach or default be deemed a waiver of any other breach or
default theretofore or thereafter occurring. Any waiver, permit, consent or
approval of any kind or character on the part of any holder of any breach or
default under this Agreement, or any waiver on the part of any holder 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 or by law or otherwise afforded to any
holder, shall be cumulative and not alternative.

         9.7 Severability. In case any provision of this Agreement shall be
invalid, illegal or unenforceable, it shall be modified in such manner as to be
valid, legal, and enforceable but so as to most nearly retain the intent of the
parties, and the validity, legality and enforceability of the remaining
provisions of this Agreement shall not in any way be affected or impaired
thereby.

         9.8 Titles and Subtitles. The titles and subtitles of this Agreement
are intended for reference and shall not by themselves determine the
construction or interpretation of this Agreement.

         9.9 Counterparts. This Agreement may be executed in any number of
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

         9.10 Expenses. The Company and each Purchaser shall pay its own costs
and expenses in connection with the negotiation, execution, delivery and
performance of this Agreement.

                                       20
<PAGE>   24

         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by their respective representatives thereunto duly authorized as of the
day and year first above written.

                            B.I. SYSTEMS CORPORATION

                            By:         /s/ Jeffrey S. Williams
                                    -------------------------------------
                                            Jeffrey S. Williams
                                    President and Chief Executive Officer

                            MILLIPORE CORPORATION

                            By:     /s/ Michael P. Carroll
                                    -------------------------------------
                                    Name:
                                    Title:
                                    Address:

               SIGNATURE PAGE TO SERIES M STOCK PURCHASE AGREEMENT

                                       21

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00001-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00001-of-00352.parquet"}]]