SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

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SCHEDULE 14D-9

SOLICITATION/RECOMMENDATION STATEMENT
PURSUANT TO SECTION 14(D)(4)
OF THE SECURITIES EXCHANGE ACT OF 1934

(AMENDMENT NO. )

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ENDOGEN, INC.
(Name of Subject Company)

ENDOGEN, INC.
(Name of Person(s) Filing Statement)

COMMON STOCK, PAR VALUE $0.01 PER SHARE
(Title of Class of Securities)

29264J 10 8
(CUSIP Number of Class of Securities)

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Owen A. Dempsey
President and Chief Executive Officer
Endogen, Inc.
30 Commerce Way
Woburn, MA 01801-1059
(781) 937-0890

(Name, Address and Telephone Number of Person Authorized to Receive Notices and
Communications on Behalf of the Person(s) Filing Statement)

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Copy To:
Brian D. Goldstein, Esq.
Testa, Hurwitz & Thibeault, LLP
125 High Street
Boston, Massachusetts 02110
(617) 248-7000

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ITEM 1. SECURITY AND SUBJECT COMPANY.

The name of the subject company is Endogen, Inc., a Massachusetts
corporation (the "COMPANY"), and the address of the principal executive offices
of the Company is 30 Commerce Way, Woburn, Massachusetts 01801-1059. The title
of the class of the Company's equity securities to which this statement relates
is Common Stock, par value $0.01 per share (each a "SHARE," and collectively,
the "SHARES").

ITEM 2. TENDER OFFER OF THE BIDDER.

This statement relates to the tender offer by EWOK Acquisition Corp., a
Massachusetts corporation (the "PURCHASER"), a direct wholly-owned subsidiary of
PerBio Science AB, a Swedish corporation ("PARENT"), to purchase all of the
outstanding Shares at a price of $3.75 per Share, net to the seller in cash
without interest (the "OFFER PRICE"), upon the terms and subject to the
conditions set forth in the Offer to Purchase dated June 2, 1999 (the "OFFER TO
PURCHASE"), and the related Letter of Transmittal (which, together with the
Offer to Purchase and any amendments or supplements thereto collectively
constitute the "OFFER").

The Offer is disclosed in a Tender Offer Statement on Schedule 14D-1, dated
June 2, 1999 (the "SCHEDULE 14D-1"), which was filed with the Securities and
Exchange Commission (the "COMMISSION") pursuant to the Securities Exchange Act
of 1934, as amended (the "EXCHANGE ACT"), and the rules promulgated by the
Commission thereunder. The Offer is being made pursuant to the Agreement and
Plan of Merger (the "MERGER AGREEMENT") dated as of May 27, 1999 among Parent,
Purchaser and the Company. The Merger Agreement provides that Purchaser's
obligation to accept for payment and to pay for any Shares tendered is subject
to, among other things, there being tendered and not withdrawn at least
two-thirds of all outstanding Shares on a fully diluted basis prior to the
expiration of the Offer or any extension thereof (the "MINIMUM CONDITION"). The
Merger Agreement provides, among other things, that as soon as practicable after
the completion of the Offer and the satisfaction or waiver of the conditions set
forth in the Merger Agreement, including the Minimum Condition, Purchaser will
be merged with and into the Company (the "MERGER"), and the Company will
continue as the surviving corporation of the Merger and as a wholly-owned
subsidiary of Parent (the "SURVIVING CORPORATION"). At the effective time of the
Merger, each Share then outstanding (other than Shares held by Parent, by
Purchaser, in the treasury of the Company or by any subsidiary of Parent,
Purchaser or the Company, all of which will be canceled, and other than Shares,
if any, held by stockholders who have perfected rights as dissenting
stockholders under Massachusetts law) will be converted into the right to
receive $3.75 in cash or any higher price per Share paid in the Offer. A copy of
the Merger Agreement has been filed as Exhibit 1 to this statement and is
incorporated herein by reference.

As set forth in the Schedule 14D-1, the address of the principal executive
offices of Parent is SE-284 80 Perstorp, Sweden and the address of the principal
executive offices of Purchaser is 3747 North Meridian Road, Rockford, Illinois
61101.

ITEM 3. IDENTITY AND BACKGROUND.

(a) The name and business address of the Company, which is the person filing
this statement, is set forth above under Item 1.

(b) Except as forth in this Item 3(b), to the knowledge of the Company, as
of the date hereof, there are no material contracts, agreements,
arrangements or understandings or actual or potential conflicts of
interest between the Company or its affiliates and (1) the Company and
its executive officers, directors or affiliates or (2) Parent or
Purchaser or their respective executive officers, directors or
affiliates.

(1) CERTAIN MATERIAL CONTRACTS, AGREEMENTS, ARRANGEMENTS OR
UNDERSTANDINGS AND ANY ACTUAL OR POTENTIAL CONFLICTS OF INTERESTS BETWEEN
(A) THE COMPANY OR ITS AFFILIATES AND (B) THE COMPANY AND ITS EXECUTIVE
OFFICERS, DIRECTORS OR AFFILIATES.

PROXY DISCLOSURE

Certain material contracts, agreements, arrangements or understandings
between the Company and its directors, executive officers and affiliates are
described on pages 4, 8 and 9 of the Company's Proxy Statement dated as of
September 25, 1998 for its 1998 Annual Meeting of Stockholders (the "PROXY
STATEMENT"). Pages 4, 8 and 9 of the Proxy Statement have been filed as Exhibit
2 to this statement and are incorporated herein by reference.

EMPLOYMENT, CONSULTING AND SEVERANCE ARRANGEMENTS

Pursuant to a letter, dated as of July 2, 1998, from the Company to Charles
R. Burke, Ph.D., a director of the Company, Dr. Burke is entitled to the same
compensation paid to all non-employee directors of the Company, and is also
entitled to receive $500 per half-day meeting with the Company's President and
Chief Executive Officer which is not a Board or Committee meeting and an option
to purchase 6,000 shares of the Company's Common Stock pursuant to the Company's
1992 Stock Plan (the "1992 PLAN"). These options were granted at an exercise
price of $2.88 per share, which was 100% of the fair market value of the
Company's Common Stock as of the date of grant. One-third of these options
vested on the date of grant and, provided that Dr. Burke continues to serve the
Company in the capacity of employee, officer, director or consultant, the
balance of the options will vest over a period of two years, in two equal annual
installments.

Pursuant to a letter agreement, dated as of September 11, 1998, between the
Company and Christine Burns, the Company's Vice President--Product Development
and Technology, during the first year of Dr. Burns' employment her annual base
salary was set at $128,000 and her annual incentive pay was set at a maximum of
$24,000. During the second year of Dr. Burns' employment her annual base salary
will be increased to $144,000 and her incentive pay will be set at a maximum of
$24,000. In addition, if, through no fault of her own, Dr. Burns' employment
with the Company is terminated, she will be entitled to a severance package in
the form of salary continuation for a period of six months from her last date of
employment, at the rate of her then current annual base salary, and medical
benefits will also be continued for up to six months.

Pursuant to a letter, dated as of September 30, 1998, from the Company to
Dennis Walczewski, the Company's Vice President of Sales, Mr. Walczewski's
annual compensation was adjusted retroactively such that effective December 1,
1997 his annual base salary was increased to $99,000 and his incentive pay was
set at a maximum of $48,000. Mr. Walczewski's annual base salary as of December
1, 1998 was fixed at $106,000 and his annual incentive compensation was fixed at
a maximum of $48,000. In addition, if through no fault of his own, Mr.
Walczewski's employment is terminated, he will be entitled to a severance
package in the form of salary continuation for a period of six months from his
last date of employment, at the rate of his current annual base salary, and
medical benefits will also be continued for up to six months.

STOCK OPTION ACCELERATION AND CASH OUT

Pursuant to the 1992 Plan and the option agreements issued thereunder, upon
the consummation of the Offer the holders of stock options granted under the
1992 Plan, including the executive officers of the Company and participating
directors, will receive a cash payment in connection with the cancellation of
their options. The cash payment for each option that has an exercise price that
is lower than the Offer Price will equal the difference between the Offer Price
and the exercise price of such option, multiplied by the number of Shares
subject to such option (whether vested or unvested). The Company will make
aggregate payments equal to approximately $401,390. Of that total, Mr. Owen A.
Dempsey will receive approximately $110,000 and Dr. Burns will receive
approximately $60,000. The Company will make aggregate payments to non-employee
directors under the 1992 Plan in the amount of $12,420. Of that

total, Mr. Hayden Harris will receive approximately $7,200 and Dr. Burke will
receive approximately $5,220.

Non-employee directors of the Company holding stock options granted pursuant
to the Company's 1993 Non-Employee Director Stock Option Plan (the "1993 PLAN")
will receive a cash payment in connection with the cancellation of their
options. The cash payment for each option that has an exercise price that is
lower than the Offer Price will equal the difference between the Offer Price and
the exercise price of such option, multiplied by the number of vested (but not
unvested) Shares subject to such option. The Company will make aggregate
payments equal to approximately $40,520. Of that total, Mr. Wallace Dempsey will
receive approximately $19,880; Mr. Harris will receive approximately $19,880;
Mr. Irwin Gruverman will receive approximately $380; and Dr. Wolfgang Woloszczuk
will receive approximately $380.

INTERESTS OF CERTAIN PERSONS IN THE OFFER AND MERGER. In considering the
recommendations of the Board set forth in Item 4(a) below, the Company's
stockholders (the "STOCKHOLDERS") should be aware that certain executive
officers of the Company and members of the Board of Directors have interests in
the Merger and the Offer, which are described in this statement, and in Annex A,
and which may present them with certain conflicts of interest.

(2) CERTAIN MATERIAL CONTRACTS, AGREEMENTS, ARRANGEMENTS OR
UNDERSTANDINGS AND ANY ACTUAL OR POTENTIAL CONFLICTS OF INTEREST BETWEEN (A)
THE COMPANY OR ITS AFFILIATES AND (B) PARENT OR PURCHASER AND THEIR
RESPECTIVE EXECUTIVE OFFICERS, DIRECTORS OR AFFILIATES.

For a description of certain agreements or understandings between the
Company, on the one hand, and Parent or Purchaser or certain affiliates of
Parent or Purchaser, on the other, see the information set forth below and in
Item 4 of this statement under the heading "Background of the Transaction: Past
Contacts, Transactions and Negotiations with Parent and Purchaser."

CONFIDENTIAL DISCLOSURE AGREEMENT

The following is a summary of certain material provisions of the
Confidential Disclosure Agreement, dated as of January 11, 1999, between the
Company and Pierce Chemical Company ("PIERCE"), an affiliate of Parent (the
"CONFIDENTIALITY AGREEMENT"). This summary does not purport to be complete and
is qualified in its entirety by reference to the complete text of the
Confidentiality Agreement, a copy of which has been filed as Exhibit 3 to this
statement and is incorporated herein by reference.

The Confidentiality Agreement contains customary provisions pursuant to
which, among other matters, Pierce agreed to keep confidential all non-public,
confidential or proprietary information furnished to it by the Company relating
to the Company, subject to certain exceptions (the "CONFIDENTIAL INFORMATION")
and to use the Confidential Information solely for the purpose of evaluating a
possible transaction involving the Company.

EXCLUSIVITY AGREEMENT

The following is a summary of certain material provisions of the Exclusivity
Agreement (the "EXCLUSIVITY AGREEMENT") dated as of May 12, 1999 by and between
the Company and Pierce. This summary does not purport to be complete and is
qualified in its entirety by reference to the complete text of the Exclusivity
Agreement, a copy of which has been filed as Exhibit 4 to this statement and is
incorporated herein by reference

The Exclusivity Agreement contains customary provisions, pursuant to which,
among other matters, the Company agreed (i) to provide Pierce and
representatives of Pierce reasonable access to the books, records, properties
and personnel of the Company, including records of the Company's independent
certified public accountants, (ii) to cease any ongoing discussions with other
parties that relate to a transaction or series of transactions similar to those
contemplated by the Merger Agreement and (iii) subject to the Board of
Directors' fiduciary duties, not to solicit, initiate or otherwise engage in
negotiations or communications with other parties regarding transactions of the
type contemplated by the Merger Agreement for a period of ten days. The
Exclusivity Agreement expired on May 22, 1999 and was not extended.

MERGER AGREEMENT

The following is a summary of certain material provisions of the Merger
Agreement. Defined terms used below and not defined herein have the respective
meanings assigned to those terms in the Merger Agreement. This summary does not
purport to be complete and is qualified in its entirety by reference to the
complete text of the Merger Agreement, a copy of which is filed as Exhibit 1
hereto and incorporated herein by reference.

The Merger Agreement provides that following the satisfaction of the
conditions described below under "Conditions to the Merger," the Purchaser will
be merged with and into the Company, and each then outstanding Share (other than
Shares then owned by the Company, Parent, or any direct or indirect wholly owned
subsidiary of Parent or by stockholders, if any, who dissent from the Merger and
comply with all of the provisions of the Massachusetts Business Corporation Law
("MBCL") concerning the right, if applicable, of holders of Shares to seek
appraisal of their Shares) will be converted into the right to receive the price
per Share paid in the Offer.

THE OFFER. The Merger Agreement provides for the making of the Offer. The
obligation of the Purchaser to accept for payment or pay for Shares tendered
pursuant to the Offer is subject to the satisfaction of the Minimum Condition
and certain other conditions that are described below. The Merger Agreement
provides that the Purchaser may extend the Offer by giving oral or written
notice of such extension to the depositary, without the consent of the Company,
only (1) if at the Expiration Date (as defined in the Merger Agreement) any of
the conditions to the Purchaser's obligations to accept Shares for payment are
not satisfied or waived, until such time as such conditions are satisfied or
waived (each individual extension not to exceed five (5) business days after the
previously scheduled Expiration Date), (2) for any period required by any rule,
regulation, interpretation or position of the Commission or the staff thereof
applicable to the Offer, and (3) on up to two occasions in each case for period
of not more than five (5) business days beyond the latest Expiration Date if on
such Expiration Date there shall have been tendered more than the number of
Shares sufficient to satisfy the Minimum Condition but less than 90% of the
Shares. In addition, the Purchaser has agreed in the Merger Agreement that it
will not, without the express written consent of the Company and after giving
oral or written notice of such extension to the depositary, (1) reduce the
number of Shares subject to the Offer, (2) reduce the Offer Price, (3) add to or
modify the conditions of the Offer, including the Minimum Condition, (4) except
as provided above, extend the Offer if all of the conditions of the Offer are
satisfied or waived, (5) change the form of the consideration payable in the
Offer or (6) amend or alter any term of the Offer in any manner materially
adverse to the Company's stockholders; provided, however, that nothing contained
in the Merger Agreement will prohibit the Purchaser, in its sole discretion
without the consent of the Company, from waiving satisfaction of any condition
of the Offer other than the Minimum Condition.

Pursuant to the Merger Agreement, the Company has granted the Purchaser an
irrevocable option (the "PURCHASER STOCK OPTION") to purchase up to 690,172
shares of the Company's Common Stock, representing approximately 19.9% of the
Company's outstanding Common Stock, at a price per share equal to the Offer
Price payable in cash. The Purchaser Stock Option may be exercised, in whole or
in part, at any time and from time to time after the date on which the Purchaser
has accepted for payment the Shares tendered pursuant to the Offer and subject
to satisfaction of the Minimum Condition if, but only if, Parent and Purchaser
agree to permanently waive the conditions of the Offer.

THE MERGER. The Merger Agreement provides that, upon the terms and subject
to the conditions thereof, the Purchaser shall be merged with and into the
Company. As a result of the Merger, the separate corporate existence of the
Purchaser will cease and the Company will be the surviving corporation (the
"SURVIVING CORPORATION"). As a result of the Merger, each Share issued and
outstanding immediately prior to the Effective Time (as defined in the Merger
Agreement) (other than Shares then owned by the Company, Parent, the Purchaser
or any other direct or indirect wholly owned subsidiary of Parent, or by
stockholders of the Company, if any, who dissent from the Merger and comply with
all the provisions of

the MBCL concerning the right, if applicable, of holders of Shares to seek
appraisal of their Shares) will be converted into the right to receive the price
paid in the Offer, in cash, without interest (the "MERGER CONSIDERATION"). As a
result of the Merger each issued and outstanding share of capital stock of
Purchaser will be automatically converted into one share of the common stock of
the Surviving Corporation.

TERMINATION OF THE MERGER AGREEMENT. The Merger Agreement may be terminated
at any time prior to the Effective Time, whether before or after approval of the
terms of the Merger Agreement by the stockholders of the Company, (1) by mutual
written consent of the Company and Parent, (2) by either the Company or Parent
if (a)(i) as a result of any of the conditions to the Offer not being satisfied,
the Offer shall have been terminated or expired in accordance with its terms
without the Purchaser having accepted for payment any Shares pursuant to the
Offer (including the Minimum Condition) or (ii) the Purchaser shall not have
accepted for payment any Shares pursuant to and subject to the conditions to the
Offer by July 31, 1999; provided, however, that the right to terminate the
Merger Agreement pursuant to clause (2)(a) will not be available to any party
whose failure to perform any of its obligations under the Merger Agreement
proximately contributed to the failure of any such condition or if the failure
of such condition results from facts or circumstances that constitute a breach
of any representation or warranty under the Merger Agreement by such party or
(b) if any Federal, state or local government or any court, tribunal,
administrative agency or commission or other regulatory authority or agency,
domestic, foreign or supranational (a "GOVERNMENTAL ENTITY"), shall have issued
any order, decree or ruling or taken any action permanently enjoining,
restraining or otherwise prohibiting the acceptance for payment of, or payment
for, Shares pursuant to the Offer or the Merger and such order, decree or ruling
or other action has become final and nonappealable, (3) by Parent or the
Purchaser prior to the Purchaser's obligation to accept Shares for payment
pursuant to the Offer, in the event of a material breach (as defined in the
Merger Agreement) by the Company of any representation, warranty, covenant or
other agreement contained in the Merger Agreement which would or reasonably
would be expected to give rise to the failure of a condition of the Offer, (4)
by Parent or the Company if, prior to the obligation of the Purchaser to accept
Shares for payment pursuant to the Offer, the Company (i) amends this Schedule
14D-9 or takes other action to modify its recommendation that the Offer and the
Merger are fair to and in the best interest of the Company and its stockholders
and its recommendation that the Company's stockholders accept the Offer, tender
their shares pursuant to the Offer and approve and adopt the Merger and the
Merger Agreement or (ii) enters into an acquisition agreement for an Alternative
Transaction (as defined below) that constitutes a Superior Proposal (as defined
below) and (5) by the Company if Parent or the Purchaser shall have (a) failed
to commence the Offer within five business days of the date of the Merger
Agreement, (b) failed to pay for Shares pursuant to the Offer in accordance with
the terms of the Merger Agreement or (c) breached in any material respect any of
their respective representations, warranties, covenants or other agreements
contained in the Merger Agreement, which breach or failure to perform in respect
of clause (c) is incapable of being cured or has not been cured within 30 days
after the giving of written notice to Parent or the Purchaser, as applicable,
except in any case under clause (c), such breaches and failures which would not
prevent the consummation of the Offer or the Merger subject to the terms and
conditions of the Merger Agreement.

ALTERNATIVE TRANSACTIONS. The Merger Agreement provides that the Company
and its subsidiaries shall not, and shall not authorize or permit any of its
officers, directors or employees or any investment banker, financial advisor,
attorney, accountant or other representative retained by it to, directly or
indirectly, (1) solicit, initiate or furnish any information in response to any
inquiries or the making of any proposal that may lead to an Alternative
Transaction or (2) participate in any discussions or negotiations regarding any
Alternative Transaction; provided, however, that if, at any time prior to the
acceptance for payment of Shares pursuant to and subject to the conditions
(including the Minimum Condition) of the Offer, the Board determines in good
faith, after consultation with its outside counsel, that action is required by
reason of the Board's fiduciary duties under applicable law, the Company may
(subject to compliance with the notification provisions discussed below), in
response to an unsolicited Third Party Proposal (as defined below), (a) furnish
information with respect to the Company to any person making

such Third Party Proposal pursuant to a confidentiality agreement that is at
least as protective of the Company's interest as is the Confidentiality
Agreement and (b) participate in negotiations regarding such Alternative
Transaction.

The Merger Agreement defines "THIRD PARTY PROPOSAL" as a bona fide proposal
from a third party, which proposal did not result from a breach of the
restrictions described above relating to a Third Party Proposal and which third
party the Board determines in good faith and upon the advice of AH&H or another
financial advisor of nationally recognized reputation to be reasonably capable
of completing a Superior Proposal. The Merger Agreement defines "ALTERNATIVE
TRANSACTION" as any direct or indirect acquisition or purchase of assets of the
Company and its subsidiaries outside the ordinary course of business or
outstanding equity securities of the Company or any subsidiary, any tender offer
or exchange offer that if consummated would result in any person beneficially
owning equity securities of the Company or any merger, consolidation, business
combination, sale of substantially all the assets, recapitalization,
liquidation, dissolution or similar transaction that would result in the
acquisition of the Company or any subsidiary, other than the transactions
contemplated by the Merger Agreement and other than the acquisition of Shares
pursuant to the exercise of Company Stock Options or Warrants (each as defined
below) which are issued and outstanding as of the date of the Merger Agreement.

The Merger Agreement provides further that unless the Board shall have
terminated the Merger Agreement as described below, neither the Board nor any
committee thereof will (1) withdraw or modify, or propose to withdraw or modify,
the approval or recommendation by such Board or such committee of the Offer, the
Merger Agreement or the Merger, (2) approve or recommend, or propose to approve
or recommend, any Alternative Transaction or (3) cause the Company to enter into
any letter of intent, agreement in principle, acquisition agreement or other
agreement (an "ACQUISITION AGREEMENT") with respect to any Alternative
Transaction, unless in connection with the taking of any action described in
clause (1), (2) or (3) the Board shall have previously terminated the Merger
Agreement in connection with a Superior Proposal (as set forth above in clause
(4) of the section entitled "Termination of the Merger Agreement").
Notwithstanding the preceding sentence, if the Company's Board determines in its
good faith judgment, after taking into consideration the advice of its outside
legal counsel, that it is required by reason of their fiduciary duties under
applicable law, the Company's Board of Directors may: (A) withdraw its
recommendation of the Offer or the Merger and the other transactions
contemplated thereby, or (B) approve or recommend or cause the Company to enter
into an agreement with respect to a Superior Proposal; provided, however, that
the Company concurrently terminates this Agreement and pays the Parent a
termination fee, including Expenses (as defined below), in the amount of one
million dollars ($1,000,000).

The Merger Agreement defines a "SUPERIOR PROPOSAL" to be any Third Party
Proposal to acquire, directly or indirectly, all of the Shares or all or
substantially all of the assets of the Company; provided that (a) the Board
determines in its good faith judgment (after consulting with a financial advisor
of nationally recognized reputation) that such Third Party Proposal is on terms
that are more favorable to the Company's stockholders from a financial point of
view than the Offer and the Merger (taking into account all relevant factors,
including the amount and form of consideration to be received in respect of the
Shares, the relative value of any non-cash consideration and the timing and
certainty of closing), and (b) the Board determines in its good faith judgment
(after consultation with outside counsel) that the failure to recommend or
accept such Third Party Proposal would be required in order for its members to
comply with their fiduciary duties under applicable law.

In addition to the obligations of the Company set forth in the preceding
paragraphs, the Merger Agreement provides that the Company as promptly as
reasonably practicable shall advise Parent orally and in writing of any request
for information or of any proposal or any inquiry regarding any Alternative
Transaction and the material terms and conditions of such request, proposal or
inquiry. The Company is further required under the terms of the Merger
Agreement, to the extent reasonably practicable and not in violation of the
Board's fiduciary duties under applicable law, after consultation with its
outside counsel, to

keep Parent fully informed of the status and details (including amendments or
proposed amendments) of any such request, proposal or inquiry. The Merger
Agreement provides that nothing contained therein shall prohibit the Company
from taking and disclosing to its stockholders a position contemplated by Rule
14e-2(a) promulgated under the Exchange Act or from making any disclosure to the
Company's stockholders with respect to any Third Party Proposal if (1) in the
good faith judgment of the Board, after consultation with its outside counsel,
such disclosure is required by reason of the Board's fiduciary duties under
applicable law and (2) the Company shall have provided Parent and the Purchaser
with reasonable advance notice of its position and proposed disclosure under the
circumstances; provided, however, that neither the Company nor its Board nor any
committee thereof is permitted, except as permitted by the Merger Agreement, to
withdraw or modify, or propose to withdraw or modify, its position with respect
to the Offer, the Merger or the Merger Agreement or approve or recommend, or
propose to approve or recommend, an Alternative Transaction.

FEES AND EXPENSES. The Merger Agreement provides that in the event that the
Merger Agreement is terminated (1) by Parent or Purchaser pursuant to clause (3)
under the section above entitled "Termination of the Merger Agreement," (2) by
Parent pursuant to and in accordance with clause (2)(a)(i) under the section
above entitled "Termination of the Merger Agreement" if such termination results
from the failure of the conditions described in clauses (c), (f) or (h) under
the section below entitled "Certain Conditions of the Offer" as a result of any
breach by the Company of any covenant or agreement or any representation or
warranty made by the Company in the Merger Agreement or (3) pursuant to clause
(4) under the section above entitled "Termination of the Merger Agreement," the
Company shall promptly pay to Parent a termination fee, including all Expenses,
in the amount of one million dollars ($1,000,000). The Merger Agreement defines
"EXPENSES" as all out-of-pocket expenses incurred by the Purchaser and Parent in
connection with the Merger Agreement, the Stockholder Agreement and the
transactions contemplated thereby.

CONDUCT OF BUSINESS BY THE COMPANY. The Merger Agreement provides that
during the term of the Merger Agreement, the Company shall, and shall cause each
of its subsidiaries to, carry on its business in the ordinary course and use its
best efforts to preserve intact its current business organization, keep
available the services of its current officers and employees as appropriate and
preserve its relationships with customers, suppliers, licensors, licensees and
others having business dealings with it. The Merger Agreement further provides
that, except as otherwise expressly contemplated by the Merger Agreement or
approved by Parent in writing (which approval shall not be unreasonably withheld
or delayed), the Company shall not and shall cause its subsidiaries not to (1)
(a) declare, set aside or pay any dividends on, or make any other distributions
in respect of, any of its capital stock, (b) split, combine or reclassify any of
its capital stock or issue or authorize the issuance of any other securities in
respect of, in lieu of or in substitution for shares of its capital stock or (c)
purchase, redeem or otherwise acquire any shares of capital stock of the Company
or any other securities thereof or any rights, warrants or options to acquire
any such shares or other securities; (2) issue, deliver, sell, pledge or
otherwise encumber any shares of its capital stock, any other voting securities
or any securities convertible into, or any rights, warrants or options to
acquire, any such shares, voting securities or convertible securities (other
than the issuance of Shares upon the exercise of Company Stock Options or
warrants to purchase Shares outstanding on the date of the Merger Agreement in
accordance with their present terms); (3) amend its articles of organization or
by-laws; (4) acquire or agree to acquire (A) by merging or consolidating with,
or by purchasing a substantial portion of the assets of, or by any other manner,
any business or any corporation, partnership, joint venture, association or
other business organization or division thereof or (B) any assets except for the
purchase of assets for an amount which does not exceed, individually or in the
aggregate, $100,000; (5) sell, lease, license, mortgage or otherwise encumber or
subject to any lien or otherwise dispose of any of its properties or assets,
except sales of inventory or sales of immaterial assets; (6) (A) except for
certain existing indebtedness and certain short-term borrowings incurred in the
ordinary course of business, incur any indebtedness for borrowed money or
guarantee any such indebtedness of another person, issue or sell any debt
securities or warrants or other rights to acquire any debt securities of

the Company, guarantee any debt securities of another person, enter into any
"keep well" or other agreement to maintain any financial statement condition of
another person or enter into any arrangement having the economic effect of any
of the foregoing or (B) make any loans, advances or capital contributions to, or
investments in, any other person; (7) make or agree to make any capital
expenditure or expenditures with respect to property, plant or equipment which,
individually, is in excess of $75,000 or, in the aggregate, are in excess of
$250,000; (8) except as required by law or as consistent with past practice,
make any tax election or settle or compromise any income tax liability or take
any action or position inconsistent with the past tax or accounting practices of
the Company; (9) with certain exceptions, pay, discharge, settle or satisfy any
claims, liabilities or obligations (absolute, accrued, asserted or unasserted,
contingent or otherwise), other than the payment, discharge or satisfaction, in
the ordinary course of business consistent with past practice or in accordance
with their terms, of liabilities reflected or reserved against in, the most
recent consolidated financial statements (or the notes thereto) of the Company
included in any report of the Company filed with the Commission and publicly
available prior to the date of the Merger Agreement or incurred thereafter in
the ordinary course of business consistent with past practice, or waive the
benefits of, or agree to modify in any material respect, any confidentiality,
standstill or similar agreement to which the Company or any subsidiary is a
party, (10) except in the ordinary course of business, modify, amend or
terminate any material contract, agreement, arrangement or other instrument
(including any amendments thereto) to which the Company or any of its
subsidiaries is a party or waive, release or assign any rights or claims; (11)
enter into any contracts, agreements, arrangements or instruments (including any
amendments thereto) relating to the distribution, sale or marketing by third
parties of the Company's or its subsidiaries' products or services or enter into
any such arrangement with any supplier of the Company unless terminable upon no
more than thirty (30) days notice; (12) except as required to comply with
applicable law and subject to exceptions for the Employment Agreements, (A)
adopt, enter into, terminate or amend any benefit plan or other arrangement for
the benefit or welfare of any director, officer or current or former employee,
(B) increase in any manner the compensation or fringe benefits of, or pay any
bonus to, any director, officer or employee (except for normal increases or
bonuses, in the ordinary course of business consistent with past practice), (C)
pay any benefit not provided for under any benefit plan other than bonuses in
the ordinary course of business consistent with past practice, (D) except as
permitted in clause (B), grant any awards under any bonus, incentive,
performance or other compensation plan or arrangement or benefit plan (including
the grant of stock options, stock appreciation rights, stock based or stock
related awards, performance units or restricted stock, or the removal of
existing restrictions in any benefit plans or agreement or awards made
thereunder) or (E) take any action other than in the ordinary course of business
to fund or in any other way secure the payment of compensation or benefits under
any employee plan, agreement, contract or arrangement or benefit plan; or (13)
authorize any of, or commit or agree to take any of, the foregoing actions.

Pursuant to the Merger Agreement, the Company shall not take any action or
omit to take any action, the taking or omission of which could reasonably be
expected to result in (1) any of its representations and warranties set forth in
the Merger Agreement becoming untrue or inaccurate in any material respect or
(2) any of the conditions to the Offer or to the Merger not being satisfied
(subject to exceptions specifically permitted by the Merger Agreement).

STOCK OPTIONS. The Merger Agreement provides that as soon as practicable
following the date of the Merger Agreement but in no event later than the
consummation of the Offer, the Company (or, if appropriate, the Board or any
committee administering the Stock Option Plans) shall (including by adopting
resolutions or taking any other actions) take action so as to allow that each
outstanding option to purchase Shares (a "COMPANY STOCK OPTION") granted under
any stock option, stock appreciation rights or stock purchase plan, or other
right, program, arrangement or agreement of the Company (collectively, the
"STOCK OPTION PLANS") and each outstanding warrant to purchase Shares (a
"WARRANT") in each case outstanding immediately prior to the date of the Merger
Agreement: (A) to the extent then exercisable, either (1) to be cancelled
immediately after consummation of the Offer in exchange for an amount in cash,
payable at the time of such cancellation, equal to the product of (x) the number
of Shares subject to such

Company Stock Option or Warrant immediately prior to the Effective Time and (y)
the excess, if any, of the price per Share to be paid in the Offer over the per
Share exercise price of such Company Stock Option or Warrant (the "NET AMOUNT")
or (2) to be converted immediately prior to the Effective Time into the right
solely to receive the Net Amount; provided, however, that no such cash payment
has been made or (B) to the extent not then exercisable, to be canceled
immediately after consummation of the Offer. The Company shall not make, or
agree to make, any payment of any kind to any holder of a Company Stock Option
or a Warrant (except for the payment described above) without the consent of
Parent.

The Merger Agreement provides further that subject to the provisions set
forth above, all Stock Option Plans and the Employee Stock Purchase Plan shall
terminate as of the Effective Time and the provisions in any other benefit plan
providing for the issuance, transfer or grant of any capital stock of the
Company or any interest in respect of any capital stock of the Company shall be
terminated as of the Effective Time. The Merger Agreement provides that the
Company shall ensure that following the Effective Time, no holder of a Company
Stock Option or Warrant nor any participant in any Stock Option Plan or the
Employee Stock Purchase Plan shall have any right thereunder to acquire any
capital stock of the Company, Parent or the Surviving Corporation, and that the
Company shall use its reasonable best efforts to ensure that following the
Effective Time, no holder of any remaining Company Stock Option or Warrant nor
any participant in any Stock Option Plan shall have any right thereunder to
acquire any capital stock of the Company, Parent or the Surviving Corporation.
The Merger Agreement also provides that the Surviving Corporation shall continue
to be obligated to pay the Net Amount to holders of any Company Stock Options or
Warrants converted in accordance with clause (y) of the immediately preceding
paragraph.

INDEMNIFICATION AND EXCULPATION. Parent has agreed in the Merger Agreement
that all rights to indemnification and exculpation (including the advancement of
expenses) from liabilities for acts or omissions occurring at or prior to the
Effective Time (including with respect to the transactions contemplated by the
Merger Agreement) existing now or at the Effective Time in favor of the current
or former directors or officers of the Company as provided in its articles of
organization, its by-laws and certain indemnification agreements shall be
assumed by the Surviving Corporation in the Merger, without further action, as
of the Effective Time and shall survive the Merger and shall continue in full
force and effect without amendment, modification or repeal in accordance with
their terms; provided however, that if any claims are asserted or made within
such period, all rights to indemnification (and to advancement of expenses)
hereunder in respect of any such claims shall continue, without diminution,
until disposition of any and all such claims.

CONDITIONS TO THE MERGER. The Merger Agreement provides that the Merger is
subject to the satisfaction or waiver of certain conditions, including the
following: (1) if required by applicable law, the Merger Agreement having been
approved and adopted by the affirmative vote of the Company's stockholders by
the requisite vote in accordance with applicable law and the Company's articles
of organization and (2) no statute, rule, regulation, executive order, decree,
temporary restraining order, preliminary or permanent injunction or other order
issued by any court of competent jurisdiction or other governmental entity or
other legal restraint or prohibition preventing the consummation of the Merger
being in effect; provided, however, that each of the Company, the Purchaser and
Parent has used reasonable efforts to prevent the entry of any such injunction
or other order and to appeal as promptly as possible any injunction or other
order that may be entered.

REASONABLE EFFORTS. The Merger Agreement provides that, on the terms and
subject to the conditions of the Merger Agreement, each of the parties will use
all reasonable efforts to take, or cause to be taken, all actions, and to do, or
cause to be done, and to assist and cooperate with the other parties in doing,
all things necessary, proper or advisable to consummate and make effective, in
the most expeditious manner practicable, the Offer and the Merger and the other
transactions contemplated by the Merger Agreement.

REPRESENTATIONS AND WARRANTIES. The Merger Agreement contains various
customary representations and warranties.

CERTAIN CONDITIONS OF THE OFFER. Notwithstanding any other term of the
Offer, the Purchaser shall not be required to accept for payment or, subject to
any applicable rules and regulations of the Commission, including Rule 14e-1(c)
under the Exchange Act (relating to the Purchaser's obligation to pay for or
return tendered Shares after the termination or withdrawal of the Offer), to pay
for any Shares tendered pursuant to the Offer unless the Minimum Condition shall
have been satisfied. Furthermore, notwithstanding any other term of the Offer,
the Purchaser shall not be required to accept for payment or, subject as
aforesaid, to pay for any Shares not theretofore accepted for payment or paid
for, and except as otherwise provided in the Merger Agreement or under
applicable law, may terminate the Offer if, at any time on or after the date
hereof and before the acceptance of such Shares for payment or the payment
therefor, any of the following conditions exists and is continuing as of any
Expiration Date (other than as a result of any action or inaction of Parent or
any of its subsidiaries that constitutes a breach of the Merger Agreement):

(a) there shall be instituted or pending by any person or Governmental
Entity any suit, action or proceeding (i) challenging the acquisition by
Parent or the Purchaser of any Shares under the Offer or pursuant to the
Stockholder Agreement, seeking to restrain or prohibit the making or
consummation of the Offer or the Merger or the performance of any of the
other transactions contemplated by the Merger Agreement or the Stockholder
Agreement (including the voting provisions thereunder), or seeking to obtain
from the Company, Parent or the Purchaser any damages in connection with the
aforesaid transactions that are material in relation to the Company, (ii)
seeking to compel the Parent to dispose of or hold separate any material
portion of the business or assets of the Company or Parent and its
subsidiaries, taken as a whole, as a result of the Offer, (iii) seeking to
impose material limitations on the ability of Parent or the Purchaser to
acquire or hold, or exercise full rights of ownership of, any Shares to be
accepted for payment pursuant to the Offer or purchased under the
Stockholder Agreement, including, without limitation, the right to vote such
Shares on all matters properly presented to the stockholders of the Company,
or (iv) seeking to prohibit Parent or any of its subsidiaries from
effectively controlling in any material respect any material portion of the
assets, properties, business or operations of the Company and its
subsidiaries taken as a whole.

(b) there shall be any statute, rule, regulation, judgment, order,
injunction or other restraint enacted, entered, enforced, promulgated or
deemed applicable to the Offer or the Merger, or any other action shall be
taken by any Governmental Entity or court, that is reasonably likely to
result, directly or indirectly, in any of the consequences referred to in
clauses (i) through (iv) of paragraph (a) above; provided, however, that
each of Parent and the Purchaser shall have used reasonable efforts to
prevent the entry of any such injunction or other court order and to appeal
as promptly as possible any injunction or other court order that may be
entered;

(c) there shall have occurred and continue to exist as of any Expiration
Date any change or event that, individually or in the aggregate with any
other change or event, is materially adverse to the assets, properties,
business, financial condition, results of operations or prospects of the
Company and its subsidiaries, taken as a whole, or any occurrence that with
notice or lapse of time or both could reasonably be expected to result in
any such change or event;

(d) there shall have occurred and continue to exist as of any Expiration
Date (i) any general suspension of trading in, or limitation on prices for,
securities on the New York Stock Exchange or the NASDAQ, (ii) a declaration
of a banking moratorium or any suspension of payments in respect of banks in
the United States or any limitation by federal or state authorities on the
extension of credit by lending institutions, or a disruption of or other
event materially adversely affecting the extension of credit by lending
institutions, (iii) a commencement of a war or armed hostilities or other
national or international calamity directly or indirectly involving the
United States, which has and continues to materially adversely affect the
trading of securities on the NYSE involving the United States or (iv) in

the case of any of the foregoing existing at the time of the commencement of
the Offer, a material acceleration or worsening thereof;

(e) the representations and warranties of the Company set forth in the
Merger Agreement shall not be true and correct at the date hereof and at the
scheduled or extended Expiration Date as though made on or as of such date
(except for representations and warranties made as of a specified date) but
only if the respects in which the representations and warranties made by the
Company are inaccurate would in the aggregate have a material adverse effect
and if such breaches of representations or warranties have not been cured
within five (5) business days of written notice to Company by Parent or
Purchaser; provided, however that in no event shall Parent be obligated to
extend the Offer for more than one five (5) business day extension or beyond
July 1, 1999 in order to permit Company to cure any such breach. For
purposes of this offer condition, "material adverse effect" shall mean that
claims, demands, liabilities and losses arising out of such inaccuracy will
actually or may reasonably be expected to result in Losses suffered or
incurred by the Company, the Parent or the Purchaser, when taken as a whole,
in excess of $300,000.

(f) the Company shall have failed to perform in any material respect any
obligation or to comply in any material respect with any agreement or
covenant of the Company to be performed or complied with by it under the
Merger Agreement and such failure has a material adverse effect;

(g) the Merger Agreement shall have been terminated in accordance with
its terms; or

(h) the Company's total stockholders equity as of May 31, 1999 shall not
be at least Five Million Five Hundred Thousand Dollars ($5,500,000) as
determined in accordance with Company's past practice consistently applied;

which in the reasonable judgment of Parent, in any such case, makes it
inadvisable to proceed with the Offer or the acceptance for payment or payment
for the Shares.

The foregoing conditions other than conditions (b) and (g) are for the sole
benefit of the Purchaser and Parent and, subject to the terms of the Merger
Agreement, may be waived by the Purchaser and Parent in whole or in part at any
time and from time to time in their sole discretion. The failure by Parent or
the Purchaser at any time to exercise any of the foregoing rights shall not be
deemed a waiver of any such right, the waiver of any such right with respect to
particular facts and circumstances shall not be deemed a waiver with respect to
any other facts and circumstances and each such right shall be deemed an ongoing
right that may be asserted at any time and from time to time, except as
otherwise provided in the Merger Agreement.

STOCKHOLDER AGREEMENT

The following is a summary of certain material provisions of a Stockholder
Agreement dated as of May 27, 1999 (the "STOCKHOLDER AGREEMENT") between
Purchase, Parent and Owen A. Dempsey, Hayden H. Harris, Charles R. Burke,
Christine A. Burns, Avery W. Catlin, Wallace G. Dempsey, Irwin J. Gruverman, G&G
Diagnostics Limited Partnership I. Hayden H. Harris Living Trust DTD 3/6/98 and
Wolfgang Woloszczuk (collectively, the "SELLING STOCKHOLDERS"). This summary
does not purport to be complete and is qualified in its entirety by reference to
the complete text of the Stockholder Agreement, a copy of which has been filed
as Exhibit 5 to this statement and is incorporated herein by reference.

The Stockholder Agreement provides that each Selling Stockholder will tender
in the Offer, and the Purchaser will purchase, all Shares beneficially owned by
such Selling Stockholder (the "Subject Shares"), at a price per Share equal to
the Offer Price. Such obligations regarding the Subject Shares are subject to
the prior satisfaction or waiver of (1) the Purchaser having accepted Shares for
payment under the terms of the Offer, (2) the Minimum Condition having been
satisfied, (3) all regulatory approvals required by any applicable law, rule or
regulation having been obtained and being final, and (4) there shall exist no

preliminary or permanent injunction, or any other order by any court of
competent jurisdiction, restricting, preventing or prohibiting either the
purchase or the delivery of Subject Shares.

Each of the Selling Stockholders has agreed, until the Merger Agreement has
terminated, among other things, not to: (1) sell, transfer, give, pledge, assign
or otherwise dispose of, or enter into any contract, option or other arrangement
with respect to the sale, transfer, pledge, assignment or other disposition of,
the Subject Shares owned by such Selling Stockholder other than pursuant to the
terms of the Offer or the Merger or (2) enter into any voting arrangement,
whether by proxy, voting agreement or otherwise, in connection with, directly or
indirectly, any takeover proposal. Each of the Selling Stockholders has also
agreed until the Stockholder Agreement has terminated (and the Stockholder
Agreement includes an irrevocable proxy provision for the benefit of the
Purchaser with respect to the Shares subject to the Stockholder Agreement owned
by each Selling Stockholder), (1) to vote the Subject Shares at any meeting of
stockholders of the Company called to vote upon the Merger and the Merger
Agreement or at any adjournment thereof or in any other circumstances upon which
a vote, consent or other approval (including by written consent) with respect to
the Merger and the Merger Agreement is sought, in favor of the Merger, the
adoption by the Company of the Merger Agreement and the approval of the terms
thereof and each of the other transactions contemplated by the Merger Agreement;
and (2) to vote such Shares at any meeting of stockholders of the Company or at
any adjournment thereof or in any other circumstances upon which a Selling
Stockholder's vote, consent or other approval is sought, against (x) any
Alternative Transaction, (y) any amendment of the Company's articles of
organization or by-laws or other proposal or transaction involving the Company,
which amendment or other proposal or transaction would be reasonably likely to
impede, frustrate, prevent or nullify the Merger, the Merger Agreement or any of
the other transactions contemplated by the Merger Agreement or change in any
manner the voting rights of each class of the Company's common stock or (z) any
action that would cause the Company to breach any representation, warranty or
covenant contained in the Merger Agreement.

EMPLOYMENT AGREEMENTS

The following are summaries of certain material provisions of Employment
Agreements between Purchaser and employees of the Company. These summaries do
not purport to be complete and are qualified in their entirety by reference to
the complete text of the Employment Agreements, copies of which have been filed
as Exhibits 13 and 14 to this statement and are incorporated herein by
reference.

The Purchaser has entered into employment agreements with certain employees
of the Company including Owen A. Dempsey, the President of the Company and
Christine A. Burns, the Vice President of Product Development and Technology
(the "EMPLOYMENT AGREEMENTS"), pursuant to which such persons will serve the
Company after consummation of the Offer. The Employment Agreements were executed
as of May 27, 1999 and are not effective until the date that the Purchaser
accepts for payment the Shares as specified in Section 4 of the Offer to
Purchase. The initial term of each of the Employment Agreements is two years.

Under the Employment Agreements, Mr. Dempsey will receive a base salary of
$160,000 per year and Ms. Burns will receive a base salary of $144,000 per year.
The Purchaser has agreed to provide each of Mr. Dempsey and Ms. Burns with a
yearly bonus pursuant to a bonus plan to be agreed upon by the Purchaser and
each of them within 90 days after the Employment Agreements become effective.
Under such bonus plans, Mr. Dempsey will be entitled to earn up to an additional
$60,000 per year and Ms. Burns

will be entitled to earn up to an additional $36,000 per year. In addition, the
Purchaser has agreed to provide a yearly vehicle allowance to Mr. Dempsey
equivalent in value to $10,000 and to Ms. Burns equivalent in value to $6,000.

Under the Employment Agreements, each of Mr. Dempsey and Ms. Burns and the
Purchaser have the right to terminate the agreement upon providing notice of
such party's intention not to renew the agreement at least 90 days prior to the
expiration of the agreement's initial term. The Purchaser may terminate the
Employment Agreements at any time for cause. The Purchaser and each of Mr.
Dempsey and Ms. Burns have the right to terminate their Employment Agreements
without cause upon at least 6 months' notice. In addition, each of Mr. Dempsey
and Ms. Burns has the right to terminate his or her employment for good reason,
(such as a reduction in salary, a relocation of more than 50 miles away from the
Employee's current place of employment, or any significant adverse change in the
nature of the Employee's duties or responsibilities), upon at least 30 days'
notice to the Purchaser.

If the Purchaser terminates the employment of Mr. Dempsey or Ms. Burns by
choosing not to renew their agreements after the initial term or by terminating
their employment without cause, Mr. Dempsey and Ms. Burns are entitled to
continue to receive their salary for 12 months after their employment is
terminated. If Mr. Dempsey terminates his employment for good reason, he is
entitled to continue to receive his salary for 6 months after his employment is
terminated. If Ms. Burns terminates her employment for good reason, she remains
entitled to continue to receive her salary for 12 months after her employment is
terminated.

ITEM 4. THE SOLICITATION OR RECOMMENDATION.

(a) The Board of Directors of the Company has determined that the Merger
Agreement and the transactions contemplated thereby, including the Offer and the
Merger, are in the best interests of the Stockholders, has approved the Merger
Agreement and the transactions contemplated thereby, including the Offer and the
Merger, and recommends that the Stockholders accept the Offer and tender their
Shares pursuant to the Offer.

A copy of a letter to all Stockholders dated June 2, 1999 communicating the
recommendation of the Board of Directors has been filed as Exhibit 6 to this
statement and is incorporated by reference.

(b) BACKGROUND OF THE TRANSACTION: PAST CONTACTS, TRANSACTIONS AND
NEGOTIATIONS WITH PARENT AND PURCHASER.

Prior to August 1998, the Company from time to time held discussions with
various companies regarding possible strategic transactions. In light of
accelerated consolidation trends in the life science industry, the Board of
Directors and senior management had begun to assess the Company's prospects and
various strategies to enhance shareholder value. During special meetings of the
Board of Directors held on July 20 and July 24, 1998, the Board discussed
various alternatives for the Company and instructed the Company's President,
Owen Dempsey, to investigate retaining the services of an investment banker to
act as a financial advisor to the Company.

On August 10, 1998, the Company engaged AH&H as its financial advisor to
undertake a review of the Company's strategic alternatives, including continued
internal growth, acquisitions of or partnering with other companies and a sale
to or combination with another company, and to ascertain the parties that may
have a potential interest in partnering or combining with or acquiring the
Company.

Between September and December 1998, AH&H contacted or held discussions with
eight companies in the life science industry. The Company entered into
confidentiality agreements with all eight of the companies contacted during this
period, and some of those companies received non-public information regarding
the Company, including projected financial information.

At a regularly scheduled meeting of the Board of Directors held on September
24, 1998, the Board reviewed the activities of AH&H, including the contacts made
with potentially interested parties, and further discussed various strategic
opportunities for the Company.

After several discussions between representatives of AH&H, the Company and a
potential bidder, on November 30, 1998, the Company received a preliminary,
non-binding indication of interest to purchase all of the outstanding Shares in
a stock for stock transaction valued at the time of receipt of the indication of
interest in the range of $22 million to $24 million (including options and
warrants). This indication of interest was prior to completion of the bidder's
due diligence review. In light of the volatility of the bidder's stock, from
late November through the end of January, the Company, AH&H and the Company's
counsel conducted initial negotiations with this bidder and its financial
advisor regarding the maximum and minimum number of shares of the bidder's stock
that would be issued in the proposed transaction in the event of increases or
decreases in the market value of the bidder's stock prior to the consummation of
the transaction (the "PRICING COLLAR") and the bidder's requirement that
expenses incurred in connection with the proposed transaction be deducted from
the value of the stock to be received by the Company's stockholders. The bidder
insisted on a Pricing Collar that provided only limited protection to the
Company's stockholders if the bidder's stock price declined prior to closing the
proposed transaction.

At special meetings of the Board of Directors on December 6, 1998 and
January 20, 1999, the directors expressed their concerns regarding the Pricing
Collar and the risks it presented to the Company's stockholders in light of the
volatility of the bidder's stock, which had declined by as much as 30% during
preliminary negotiations. During the second week of January, the Company
released financial results for its second quarter that were below the bidder's
expectations, and at the end of January the bidder terminated discussions with
the Company.

Between January and April 1999, AH&H contacted 14 additional companies,
including Pierce, and the Company entered into confidentiality agreements with
five additional companies and certain of those companies received non-public
information regarding the Company. AH&H and the Company's management held
discussions with these additional companies between January and April.

During January 1999 representatives of AH&H contacted the senior management
of Pierce to inquire as to Pierce's interest in pursuing a transaction with the
Company. Following this contact, Pierce initiated a review of certain publicly
available information concerning the Company and contacted representatives of
AH&H to advise them that Pierce would be interested in reviewing non-public
information about the Company and meeting with members of the Company's senior
management. On January 11, 1999, Pierce entered into the Confidentiality
Agreement with the Company.

On February 16, 1999, representatives of Pierce met with certain members of
the Company's senior management regarding the business, strategies and prospects
of the Company.

On March 23, 1999, representatives of Pierce and its financial advisor,
Vector Securities International, Inc. ("Vector"), met with representatives of
the Company and AH&H and conducted a preliminary review of certain non-public
information. From March 23, 1999 through April 19, 1999, Pierce, Pierce's
advisors, the Company's senior management and the Company's advisors engaged in
various discussions regarding the business, strategies and prospects of the
Company and the possible terms of a potential transaction.

On April 16, 1999, the Company received a non-binding indication of interest
from a company (the "THIRD PARTY") to purchase all of the outstanding Shares in
a stock for stock transaction valued at the time of receipt of the indication of
interest in the range of $11 million to $12 million (the "APRIL 16 PROPOSAL").

On April 19, 1999, Vector, on behalf of Parent, submitted a non-binding
letter of interest to acquire all of the Shares for $3.00 per share in cash,
subject to, among other things, the Parent completing a due diligence review of
the Company and the execution of a definitive agreement (the "APRIL 19
PROPOSAL").

On April 21, 1999, at a regularly scheduled meeting of the Board of
Directors, Mr. Dempsey and representatives of AH&H reported to the Board the
April 16 Proposal and the April 19 Proposal, and reviewed the discussions with
these companies. AH&H also updated the Board on its contacts with other
potentially interested parties and advised the Board that, except for Parent and
the Third Party, no parties had expressed an interest in acquiring the Company.
The Board instructed AH&H to negotiate a higher price per Share with Parent and
the Third Party.

During the weeks of April 19 and April 26, 1999, AH&H, on behalf of the
Company, led negotiations with Parent and the Third Party. With respect to the
April 16 Proposal, the Third Party was unwilling to increase its offer price.

Representatives of AH&H and the Company continued negotiations and on April
28, 1999, Vector, on behalf of Parent, submitted a revised non-binding letter of
interest to acquire all the Shares for $3.75 per Share in cash (the "APRIL 28
PROPOSAL"). At special meetings of the Board of Directors held on April 29 and
30, 1999, Mr. Dempsey and representatives of AH&H updated the Board regarding
discussions with the Third Party and Parent. At the April 30 meeting, the Board
authorized Mr. Dempsey to proceed with further negotiations with Parent.

On May 3, 1999, Pierce and its representatives continued their review of the
Company. On May 7, 1999 the Company's counsel received an initial draft of the
proposed Merger Agreement and the proposed Stockholder Agreement. During the
week of May 10, 1999 the Company's counsel and Parent's counsel discussed a
number of issues presented by the draft Merger Agreement and draft Stockholder
Agreement. Concurrently, management of Parent and the Company began discussions
of the continued employment of certain employees of the Company.

On May 12, 1999 the Board of Directors held a special meeting to discuss the
status of the negotiations with Parent regarding the Merger Agreement. Mr.
Dempsey and the Company's counsel reviewed the issues presented in the draft
agreements and received instructions from the Board regarding the proposed
terms. At this meeting, Mr. Dempsey informed the Board that Parent insisted that
the Company enter into an exclusivity agreement before it would continue
negotiations. At the instruction of the Board, the Exclusivity Agreement was
executed later that day, which subsequently expired on May 22, 1999.

During the week of May 17, 1999, AH&H and the Company's counsel, in
consultation with senior management and the Board of Directors, continued to
negotiate with Parent's counsel the terms and conditions of the proposed Merger
Agreement, including price, termination fee, representations and warranties,
covenants, termination provisions and conditions to the Offer. During this
period, Company counsel, in consultation with management and the Board of
Directors, also continued to negotiate with Parent's counsel the terms of the
Stockholder Agreement. At a special meeting of the Board of Directors held on
May 21, 1999, representatives from AH&H and the Company's counsel provided
updates on the status of negotiations with Parent. The Company's counsel
reviewed the terms of the proposed Merger Agreement and proposed Stockholder
Agreement. In addition, Mr. Dempsey reported to the Board that Parent would
require certain employees of the Company to enter into employment agreements.
Mr. Dempsey summarized the terms of the proposed employment agreements as they
were communicated to him by senior management of Parent.

On May 24, 1999, Mr. Dempsey and certain other employees of the Company
received draft employment agreements from Parent (the "EMPLOYMENT AGREEMENTS"),
which Parent required to be entered into as a condition to entering into the
Merger Agreement. These employees of the Company retained counsel separate from
the Company's counsel to negotiate the Employment Agreements, and between May 24
and May 27, 1999, counsel to Parent and these employees, along with management
of Parent and these employees, negotiated the terms of the Employment
Agreements.

On May 24, 1999, at a special meeting of the Board of Directors, the
Company's counsel reviewed the then current terms of the proposed Merger
Agreement and proposed Stockholder Agreement, and Mr. Dempsey reviewed the terms
of the Employment Agreements. AH&H then presented a review of its financial
analysis of the proposed cash tender offer of $3.75 per Share for all Shares and
further indicated it was prepared to deliver an opinion to the Board of
Directors that the consideration to be received in the proposed Merger Agreement
was fair from a financial point of view to the Stockholders.

On May 25, 1999, at a special meeting of the Board of Directors, Mr. Dempsey
and the Company's counsel updated the Board on the status of the negotiations.
AH&H then updated its May 24, 1999 presentation to the Board of Directors
regarding its financial analysis of the Offer and presented a draft of its
opinion that the consideration to be received in the proposed Merger Agreement
was fair from a financial point of view to the Stockholders. The Board voted,
based in part on the opinion of AH&H as to the fairness of the consideration
from a financial point of view to the Stockholders and all other relevant
factors in relation to the proposed transaction with Parent, to approve the
Merger Agreement and to recommend to the Stockholders that they tender their
Shares in the Offer conditioned upon counsel and the Company's President
continuing to negotiate final transaction documents in accordance with the
Board's instructions.

Following the May 25, 1999 Board of Directors meeting, counsel for the
Company and Parent continued the final negotiation of the transaction documents.
The Merger Agreement, the Stockholder Agreement and the Employment Agreements
were executed and a joint press release was issued by the parties announcing the
Merger Agreement on the morning of May 27, 1999. The text of this release is
filed as Exhibit 7 to this statement and is incorporated herein by reference.

Reference is made to the Offer to Purchase for a description of the matters
considered by Parent in connection with the transaction.

REASONS FOR THE RECOMMENDATIONS; FACTORS CONSIDERED BY THE BOARD OF
DIRECTORS

At the meeting held on May 25, 1999, the Board of Directors approved the
Merger Agreement, and determined that the Merger Agreement and the transactions
contemplated thereby, including the Offer and the Merger, are fair to and in the
best interests of the Stockholders, and the Board of Directors resolved to
recommend that Stockholders accept the Offer and tender their Shares. In making
such recommendation and approving the Merger Agreement and the transactions
contemplated thereby, the Board of Directors considered a number of factors,
including, but not limited to, the following:

(i) the financial and other terms and conditions of the Merger
Agreement, including the proposed structure of the Offer and the Merger
involving a cash tender offer of $3.75 per Share for all outstanding Shares
to be followed by a merger for the same consideration;

(ii) the extensive negotiations between the Company and Parent, leading
to the belief by the Board of Directors that $3.75 per Share represented the
highest price per Share that could be negotiated with Parent;

(iii) the fact that the $3.75 per Share to be paid in the Offer and as
the consideration in the Merger represents: (1) a premium of approximately
87.5% over the closing sale price of $2.00 per Share as reported on the
Nasdaq SmallCap Market on April 27, 1999, 30 days prior to the execution of
the Merger Agreement; (2) a premium of approximately 28% over the $2.93
average closing price over the 20 trading days prior to the execution of the
Merger Agreement; and (3) a premium of approximately 30% over the $2.88
closing sale price for the Shares on the Nasdaq SmallCap Market on May 26,
1999, the last trading day prior to the execution of the Merger Agreement;

(iv) the financial presentation of AH&H made on May 24, 1999 (as updated
on May 26, 1999) and the written opinion received by the Company from AH&H
on May 27, 1999 to the effect that as of that date, and based upon its
review and analysis and subject to the assumptions, limitations and

qualifications set forth therein, the consideration to be received by the
Stockholders pursuant to the Merger Agreement, the Offer and the Merger is
fair to the Stockholders from a financial point of view. A copy of the
written opinion dated May 27, 1999 of AH&H, which sets forth the assumptions
made, procedures followed, other matters considered and limits of the review
by AH&H, is attached hereto as Annex B. STOCKHOLDERS ARE URGED TO READ SUCH
OPINION IN ITS ENTIRETY;

(v) the fact that neither the Offer nor the Merger is subject to any
financing condition, and that Parent has represented that it has possession
of, or has available to it under existing finance commitments, sufficient
funds available to consummate the Offer and the Merger and the transactions
contemplated thereby;

(vi) the Company's business, financial condition, assets, liabilities
and results of operation, including the substantially lower operating margin
and return on equity of the Company's operations compared to a group of its
competitors;

(vii) the consolidation trend in the life science industry and the
resulting pricing pressures on the Company's product lines;

(viii) the possibility of continuing to operate the Company as an
independent entity, and the business strategy and prospects of the Company,
as well as the various risks and uncertainties associated with those
prospects;

(ix) current financial market conditions, both generally and those
affecting "small cap" stocks like the Company, and historical market prices,
volatility, trading information and liquidity with respect to the Shares;

(x) the fact that the Company had carefully considered over several
months a full range of options, including acquiring smaller companies and
technologies, and that none of these options, in the directors' view, was
compelling given the Company's size and competitive position;

(xi) the fact that, after a more than nine-month effort by the Company
and its financial advisor, AH&H, to canvas the market for strategic partners
and merger and acquisition possibilities that would maximize value for the
Stockholders, in the directors' view the other proposals to acquire the
Company contained significant risks and contingencies, including the nature
of the consideration proposed; and the fact that none of the other proposals
during this market canvas resulted in a firm offer; and

(xii) the fact that, under the terms of the Merger Agreement, prior to
consummation of the Offer, the Board of Directors may approve a superior
proposal to be acquired by a third party if the Board of Directors has
determined in good faith, after taking into consideration advice of its
outside legal counsel, that such approval is required by reason of the Board
of Directors' fiduciary duties under applicable law, and further provided
that the Company shall have paid a termination fee (including expenses) of
$1 million to Parent.

The Board of Directors' approval and recommendation was based on the
totality of the information considered by it. The Board of Directors did not
assign relative weights to the factors considered by it or determine that any
one factor was of primary importance.

ITEM 5. PERSONS RETAINED, EMPLOYED OR TO BE COMPENSATED.

Pursuant to a letter agreement dated August 10, 1998 between the Company and
AH&H, the Company, as compensation for financial advisory services rendered by
AH&H, agreed to pay AH&H (i) $25,000 upon execution of such letter agreement,
(ii) $50,000 if the Company requests, and AH&H delivers, an opinion as to the
fairness from a financial point of view of any proposed transaction (defined as
one or a series of transactions, including, but not limited to, transactions of
the type contemplated in the

Merger Agreement), and (iii) $300,000, if a transaction of the type and size
contemplated by the Merger Agreement is consummated, less any amounts paid
pursuant to clauses (i) and (ii). In addition, the Company agreed to reimburse
AH&H for its reasonable out-of-pocket expenses incurred in connection with
rendering financial advisory services, including fees and disbursements of its
legal counsel; provided, however, that the aggregate amount of cash
reimbursements shall not exceed $20,000 except as otherwise agreed to by the
Company. In addition, if the Company receives a break-up fee, topping fee or
other termination fee in connection with the Merger Agreement and the
transactions contemplated thereby, AH&H will be entitled to 25% of such fee. The
Company also agreed to indemnify AH&H and its affiliates, and their respective
control persons, directors, officers, agents, employees and controlling persons
for certain costs, expenses and liabilities, including liabilities under the
federal securities laws.

Pursuant to a letter agreement, dated as of July 6, 1998, as amended on May
7, 1999, between the Company and Ulrich Schmid, the Company's Director of
Business Development, Mr. Schmid is entitled to a success fee of $100,000 upon
the completion of the transactions contemplated by the Merger Agreement. In
addition, if Mr. Schmid is terminated by the Company without cause, he is
entitled to receive continuation of base salary for a period of up to six months
following the date of termination. Medical benefits will also be continued
during this period, with the cost of premiums paid by the Company.

Except as set forth above, neither the Company nor any person acting on its
behalf has or currently intends to employ, retain or compensate any person to
make solicitations or recommendations to the Stockholders on its behalf with
respect to the Offer, except that such solicitations or recommendations may be
made by directors, officers or employees of the Company, for which services no
additional compensation will be paid.

ITEM 6. RECENT TRANSACTIONS AND INTENT WITH RESPECT TO SECURITIES.

(a) Neither the Company nor, to the knowledge of the Company, any of its
executive officers, directors, affiliates or subsidiaries, has effected any
transaction in the Company's securities in the past 60 days.

(b) To the knowledge of the Company, all of its executive officers,
directors, affiliates or subsidiaries who are also Stockholders presently intend
to tender their Shares in the Offer.

ITEM 7. CERTAIN NEGOTIATIONS AND TRANSACTIONS BY THE SUBJECT COMPANY.

(a) Except as set forth in this statement, the Company is not engaged in any
negotiation in response to the Offer which relates to or would result in (i) an
extraordinary transaction, such as a merger or reorganization, involving the
Company or any subsidiary of the Company, (ii) a purchase, sale or transfer of a
material amount of assets by the Company or any subsidiary of the Company, (iii)
a tender offer for or other acquisition of securities by or of the Company, or
(iv) any material change in the present capitalization or dividend policy of the
Company. Pursuant to the Merger Agreement, however, and as described under the
heading "The Merger Agreement -- Alternative Transactions" in Item 3 above, the
Company and the Board of Directors may, subject to certain limitations, take
certain actions in respect of proposed transactions necessary for the directors
of the Company to discharge their fiduciary obligations to the Company's
stockholders under applicable law.

(b) Except as described in this statement, there are no transactions,
resolutions of the Board of Directors, agreements in principle or signed
contracts in response to the Offer that relate to or would result in one or more
of the events referred to in Item 7(a) above.

ITEM 8. ADDITIONAL INFORMATION TO BE FURNISHED.

The Information Statement attached hereto as Annex A is being furnished in
connection with the contemplated designation by Purchaser, pursuant to the
Merger Agreement, of certain persons to be

appointed to the Board of Directors of the Company other than at a meeting of
the stockholders following the purchase by Purchaser, pursuant to the Offer, of
the number of shares representing not less than the number of Shares that will
satisfy the Minimum Condition.

ITEM 9. MATERIAL TO BE FILED AS EXHIBITS.

The following exhibits are filed herewith:

EXHIBIT INDEX

Exhibit No. Description
- ----------- ------------------------------------------------------------------------------

Exhibit 1 Agreement and Plan of Merger and Letter Agreement each dated as of May 27,
1999 among Parent, Purchaser and the Company.

Exhibit 2 Excerpt from the Company's Proxy Statement dated as of September 25, 1998
(inclusive of pages 4, 8 and 9 thereof).

Exhibit 3 Confidential Disclosure Agreement dated as of January 11, 1999 between the
Company and Pierce.

Exhibit 4 Exclusivity Agreement dated as of May 12, 1999 by and between Pierce and the
Company.

Exhibit 5 Stockholder Agreement dated May 27, 1999 by and among Parent, Purchaser and
certain individuals listed on Exhibit A thereto.

Exhibit 6 Letter, dated June 2, 1999, from the President and Chief Executive Officer of
the Company to the stockholders of the Company concerning the Offer.

Exhibit 7 Joint Press Release of the Company and Parent, dated May 27, 1999.

Exhibit 8 Letter, dated September 30, 1998 from the Company to Dennis Walczewski.

Exhibit 9 Letter Agreement, dated September 11, 1998 by and between the Company and
Christine Burns.

Exhibit 10 Letter dated July 2, 1998 from the Company to Charles Burke.

Exhibit 11 Form of Stock Option Agreement under the Company's 1992 Stock Plan.

Exhibit 12 1992 Stock Plan of the Company.

Exhibit 13 Employment Agreement dated May 27, 1999 between Owen Dempsey and Parent.

Exhibit 14 Employment Agreement dated May 27, 1999 between Christine Burns and Parent.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

ENDOGEN, INC.

By: /s/ OWEN A. DEMPSEY
-----------------------------------------
Owen A. Dempsey
PRESIDENT AND CHIEF EXECUTIVE
OFFICER

Dated: June 2, 1999

ANNEX A

ENDOGEN, INC.
30 Commerce Way
Woburn, MA 01801-1059

INFORMATION STATEMENT PURSUANT
TO SECTION 14(F) OF THE SECURITIES EXCHANGE
ACT OF 1934 AND RULE 14F-1 THEREUNDER
NO VOTE OR OTHER ACTION OF THE COMPANY'S
STOCKHOLDERS IS REQUIRED IN CONNECTION WITH
THIS INFORMATION STATEMENT. NO PROXIES ARE BEING
SOLICITED AND YOU ARE REQUESTED NOT TO SEND
THE COMPANY A PROXY.

This Information Statement, which is being mailed on or about June 2, 1999
to the holders of shares of the common stock, par value $0.01 per share (the
"COMMON STOCK") of Endogen, Inc., a Massachusetts corporation (the "COMPANY"),
is being furnished in connection with the designation by EWOK Acquisition Corp.,
a Massachusetts corporation ("PURCHASER") and wholly-owned Subsidiary of PerBio
Science AB, a Swedish corporation ("PARENT"), of persons to the Board of
Directors of the Company (the "BOARD"). Such designation is to be made pursuant
to an Agreement and Plan of Merger dated as of May 27, 1999 (the "MERGER
AGREEMENT") among the Company, Parent and Purchaser.

Pursuant to the Merger Agreement, among other things, the Purchaser
commenced a tender offer on June 2, 1999 to purchase all of the issued and
outstanding Common Stock at a price of $3.75 per share, net to the seller in
cash, as described in the Purchaser's Offer to Purchase dated June 2, 1999 (the
"OFFER TO PURCHASE") and the related Letter of Transmittal (which Offer to
Purchase and related Letter of Transmittal together constitute the "OFFER"). The
Offer is scheduled to expire at 12:00 midnight, New York City time, on Tuesday,
June 29, 1999, unless extended. The Offer is subject to, among other things, the
condition that at least two-thirds of all issued and outstanding shares of
Common Stock, on a fully diluted basis, be validly tendered and not withdrawn
prior to the expiration of the Offer (the "MINIMUM CONDITION"). The Merger
Agreement also provides for the Merger of Purchaser with and into the Company
(the "MERGER") as soon as practicable after the consummation of the Offer.
Following the consummation of the Merger (the "EFFECTIVE TIME"), the Company
will be the surviving corporation and a wholly-owned subsidiary of Parent. In
the Merger, each share of Common Stock issued and outstanding immediately prior
to the Effective Time (other than shares held by Parent, by Purchaser, in the
treasury of the Company or by any subsidiary of Parent, Purchaser or the
Company, all of which will be canceled, and other than shares, if any, held by
stockholders who have perfected rights as dissenting stockholders under
Massachusetts law) will be converted into the right to receive cash in the
amount of $3.75 without interest.

The Merger Agreement provides that promptly upon the acceptance for payment
of, and payment for, any Common Stock by Purchaser pursuant to and subject to
the conditions (including the Minimum Condition) of the Offer, Purchaser will
have the right to designate such number of directors of the Company (the
"PURCHASER DESIGNEES") as will give Purchaser a majority of such directors.

The terms of the Merger Agreement, a summary of the events leading up to the
Offer and the execution of the Merger Agreement and other information concerning
the Offer and the Merger are contained in the Offer to Purchase and in the
Solicitation/Recommendation Statement on Schedule 14D-9 of the Company (the
"SCHEDULE 14D-9") with respect to the Offer, copies of which are being delivered
to stockholders of the Company contemporaneously herewith. Certain other
documents (including the Merger Agreement) were filed with the Securities and
Exchange Commission (the "SEC") as exhibits to

A-1

the Tender Offer Statement on Schedule 14D-1 of Purchaser and Parent (the
"SCHEDULE 14D-1"). The exhibits to the Schedule 14D-9 and the Schedule 14D-1 may
be examined at, and copies thereof may be obtained from, the regional offices of
and public reference facilities maintained by the SEC (except that the exhibits
thereto cannot be obtained from the regional offices of the SEC) in the manner
set forth in Section 8 of the Offer to Purchase.

No action is required by the stockholders of the Company in connection with
the election or appointment of the Purchaser Designees to the Board. However,
Section 14(f) of the Securities Exchange Act of 1934, as amended (the "EXCHANGE
ACT"), requires the mailing to the Company's stockholders of the information set
forth in this Information Statement prior to a change in a majority of the
Company's directors otherwise than at a meeting of the Company's stockholders.

The information contained in this Information Statement concerning Parent,
Purchaser and the Purchaser Designees has been furnished to the Company by such
persons, and the Company assumes no responsibility for the accuracy or
completeness of such information. As set forth in the Schedule 14D-1, the
address of the principal executive offices of Parent is SE-284 80 Perstorp,
Sweden and the address of the principal executive offices of Purchaser is 3747
North Meridian Road, Rockford, Illinois 61101.

GENERAL

The Common Stock is the only class of voting securities of the Company
outstanding. Each share is entitled to one vote. As of May 24, 1999, there were
3,468,202 shares of Common Stock issued and outstanding.

THE PURCHASER DESIGNEES

The Merger Agreement provides that, promptly upon acceptance by Purchaser of
Common Stock pursuant to the Offer, if the Minimum Condition has been met,
Purchaser will have the right to designate a majority of the authorized
directors of the Company. The Offer to Purchase states that the Purchaser
Designees are Robb Anderson, Mats Fischier and Charles Granneman. It is expected
that the Purchaser Designees will assume office following the purchase by
Purchaser of such number of shares of Common Stock that satisfies the Minimum
Condition, which purchase cannot be earlier than June 29, 1999, and that, upon
assuming office, the current directors of the Company other than Mr. Owen
Dempsey will resign and the Purchaser Designees will thereafter constitute at
least a majority of the Board.

Biographical information concerning each of the Purchaser Designees is
presented below.

PURCHASER DESIGNEES

ROBB ANDERSON is the President of the Purchaser. Mr. Anderson serves as the
President of Pierce Chemical Company, an affiliate of Purchaser, and has served
as an officer of certain affiliates of Perstorp since 1978. Mr. Anderson is a
director of Purchaser and certain affiliates of Perstorp.

MATS FISCHIER is Division Manager of Perstorp Life Science, a part of the
Perstorp Group. Since 1996, Mr. Fischier has served in various capacities with
the Perstorp Group, including Division Manager of the Pernovo Division from
February 1997 to September 1998 and Division Manager of Perstorp Analytical from
January 1996 to February 1997. Prior thereto Mr. Fischier served as a Division
Manager of Nobel Industrier of Akzo Nobel.

CHARLES GRANNEMAN is the Treasurer and Secretary of the Purchaser. Mr.
Granneman has served as an officer of certain affiliates of Perstorp since 1988.

A-2

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The following table sets forth as of May 24, 1999 certain information
regarding the ownership of shares of the Company's Common Stock by (i) each
person who, to the knowledge of the Company, owned beneficially more than 5% of
the shares of Common Stock of the Company outstanding at such date ("PRINCIPAL
STOCKHOLDERS"), (ii) each current director of the Company, (iii) each Named
Officer (as defined below) of the Company, and (iv) all directors and executive
officers as a group. To the Company's knowledge, as of May 24, 1999, none of the
Purchaser Designees owned any shares of the Company's Common Stock.

AMOUNT AND NATURE OF
BENEFICIAL PERCENT OF COMMON
NAME AND ADDRESS OF BENEFICIAL OWNER OWNERSHIP(1) STOCK OUTSTANDING(2)
- -------------------------------------------------------------------- ---------------------- -----------------------

Owen A. Dempsey(3).................................................. 350,800 9.8%
c/o Endogen, Inc.
30 Commerce Way
Woburn, MA 01801

Wallace G. Dempsey(4)............................................... 190,000 5.4%
c/o Endogen, Inc.
30 Commerce Way
Woburn, MA 01801

Irwin J. Gruverman(5)............................................... 125,000 3.6%
G&G Diagnostics Corp.
30 Ossipee Road
Newton, MA 02164

Hayden H. Harris(6)................................................. 65,500 1.9%
Enterprise Management, Inc.
425 North Main Street
Ann Arbor, MI 48104

Wolfgang Woloszczuk, Ph.D.(7)....................................... 58,000 1.7%
Biomedica GmbH
Divischgasse 4
A-1210 Vienna, Austria

Avery W. Catlin(8).................................................. 39,200 1.1%
c/o Endogen, Inc.
30 Commerce Way
Woburn, MA 01801

Dennis H. Walczewski(9)............................................. 33,400 *
c/o Endogen, Inc.
30 Commerce Way
Woburn, MA 01801

Charles R. Burke, Ph.D.(10)......................................... 13,500 *
Monument Partners, Inc.
1410-1 Monument Street
Concord, MA 01742

All executive officers and directors as a group (9 persons)(11)..... 875,400 23.2%

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

* Indicates less than 1%.

A-3

(1) Except as indicated in footnotes to this table, the persons named in this
table have sole voting and investment power with respect to all shares of
Common Stock owned based upon information provided to the Company by the
directors, officers and Principal Stockholders.

(2) The number of shares of Common Stock deemed outstanding for this calculation
includes (i) 3,468,202 shares of Common Stock outstanding on May 24, 1999,
and (ii) all Common Stock underlying options which are currently exercisable
or will become exercisable within 60 days of May 24, 1999 by the person or
group in question.

(3) Mr. Owen Dempsey's beneficial ownership includes 95,700 shares issuable upon
the exercise of outstanding stock options exercisable on May 24, 1999 or
within 60 days thereafter.

(4) Mr. Wallace Dempsey's beneficial ownership includes 30,000 shares issuable
upon the exercise of outstanding stock options exercisable on May 24, 1999
or within 60 days thereafter.

(5) Mr. Gruverman's beneficial ownership includes 18,000 shares issuable upon
the exercise of outstanding stock options exercisable on May 24, 1999 or
within 60 days thereafter and 95,000 shares of Common Stock held by G&G
Diagnostics Limited Partnership I ("G&G"). Mr. Gruverman is the sole general
partner of G&G and has sole voting and investment power with respect to such
shares of Common Stock. Mr. Gruverman disclaims beneficial ownership of all
shares held by G&G, except with respect to his pecuniary interest therein,
if any.

(6) Mr. Harris's beneficial ownership includes 60,000 shares issuable upon the
exercise of outstanding stock options held by Mr. Harris and by Enterprise
Management, Inc. (of which Mr. Harris is President) exercisable on May 24,
1999 or within 60 days thereafter and 2,000 shares held in a trust for the
benefit of his children. Mr. Harris disclaims beneficial ownership of all of
the shares held in a trust for the benefit of his children.

(7) Dr. Woloszczuk's beneficial ownership includes 18,000 shares issuable upon
the exercise of outstanding stock options exercisable on May 24, 1999 or
within 60 days thereafter. Excludes 127,000 shares of Common Stock
beneficially owned by Biomedica GmbH ("BIOMEDICA"). Dr. Woloszczuk is an
executive officer and 20% shareholder of Biomedica. Dr. Woloszczuk disclaims
beneficial ownership of all shares held by Biomedica, except with respect to
his pecuniary interest therein.

(8) Mr. Catlin's beneficial ownership includes 38,200 shares issuable upon the
exercise of outstanding stock options exercisable on May 24, 1999 or within
60 days thereafter.

(9) Mr. Walczewski's beneficial ownership includes 32,200 shares issuable upon
the exercise of outstanding stock options exercisable on May 24, 1999 or
within 60 days thereafter and 200 shares held by his son. Mr. Walczewski
disclaims beneficial ownership of all shares held by his son.

(10) Dr. Burke's beneficial ownership includes 12,500 shares issuable upon the
exercise of outstanding stock options exercisable on May 24, 1999 or within
60 days thereafter.

(11) Includes 304,600 shares issuable upon the exercise of outstanding stock
options exercisable on May 24, 1999 or within 60 days thereafter. Excludes
shares indicated as being excluded in note 7.

A-4

CURRENT DIRECTORS AND EXECUTIVE OFFICERS OF THE COMPANY

The following table sets forth the names of the directors and executive
officers of the Company, their ages as of May 24, 1999, and the positions
currently held by each such person with the Company.

NAME AGE POSITION
- ----------------------------------------------------- --- -----------------------------------------------------

Owen A. Dempsey (1)(2)............................... 41 President, Chief Executive Officer and Director
Dennis H. Walczewski (1)............................. 51 Vice President of Sales
Avery W. Catlin (1).................................. 51 Vice President, Operations and Finance, Chief
Financial Officer, Clerk and Treasurer
Christine A. Burns, Ph.D. (1)........................ 46 Vice President, Product Development and Technology
Charles R. Burke, Ph.D. (2)(4)....................... 56 Director
Wallace G. Dempsey (2)............................... 73 Director
Irwin J. Gruverman (2)(3)............................ 65 Director
Hayden H. Harris (2)(3)(4)........................... 57 Chairman of the Board
Wolfgang Woloszczuk, Ph.D. (2)(4).................... 51 Director

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

(1) Executive officers of the Company are elected annually and hold office until
the first meeting of the Board of Directors after each annual meeting of
stockholders and until their successors are elected and qualified, or until
their earlier resignation or removal.

(2) The directors of the Company are elected annually and hold office until the
next annual meeting of stockholders and until their successors are elected
and qualified, or until their earlier resignation or removal.

(3) Member of the Audit Committee.

(4) Member of the Compensation Committee.

Owen A. Dempsey has been President, Chief Executive Officer and a director
of the Company since February 1986. From February 1987 to December 1996, he also
served as the Company's Treasurer. Mr. Dempsey helped to launch Endogen in 1985.
Prior to joining the Company, Mr. Dempsey held positions at the International
Management Development Institute in Lausanne, Switzerland and at the IBM
Corporation. Mr. Dempsey holds an A.B. from Dartmouth College and an M.B.A. from
Stanford University.

Dennis H. Walczewski has served as Vice President of Sales of the Company
since November 1995. From March 1995 until November 1995, Mr. Walczewski served
as Director of Sales at T Cell Diagnostics, Inc., a manufacturer of diagnostic
kits and reagents for the biotechnology industry. From March 1994 until February
1995, Mr. Walczewski was Vice President of Sales of Tropix, Inc., a producer of
research kits and reagents for the biotechnology industry. From March 1987 until
January 1994, Mr. Walczewski was Area Sales Manager at Boehringer Mannheim
Corporation, a manufacturer of diagnostic kits, clinical lab equipment and
products for the biotechnology industry.

Avery W. Catlin has served as Vice President, Finance, Chief Financial
Officer, Clerk and Treasurer of the Company since December 1996. In July 1998,
he was promoted to Vice President, Operations and Finance while retaining his
other duties. From June 1992 to April 1996, Mr. Catlin held various financial
positions at Repligen Corporation, a public biopharmaceutical company, serving
the last two years as Chief Financial Officer. Earlier in his career, Mr. Catlin
held the position of Chief Financial Officer at MediSense, Inc., a
Massachusetts-based medical device company.

Christine A. Burns, Ph.D. joined Endogen in November 1998 as Vice President,
Product Development and Technology. From 1997 until November 1998, Dr. Burns
served as Vice President, Contract R&D Services for the PerSeptive Biosystems
Division of Perkin Elmer Corporation. From 1993 to 1997, Dr. Burns held senior
management positions at PerSeptive Biosystems, Inc., including Vice President,

A-5

World Wide Technical Support (1995 to 1997) and Vice President of R&D, Clinical
Chemistry (1993 to 1995). From 1986 to 1993, Dr. Burns served in various
management positions at Advanced Magnetics, Inc., most recently as Director of
Operations and Development.

Charles R. Burke, Ph.D. has been a director of the Company since June 1998.
Dr. Burke is currently principal and founder of Monument Partners, Inc. From
January 1994 to December 1997, Dr. Burke was Chief Executive Officer of Research
Biochemicals International, a leading supplier of fine organic chemicals to the
neuroscience research community. From August 1990 to January 1994, Dr. Burke was
Vice President, General Manager Clinical Diagnostics at Gene-Trak Systems, Inc.,
a developer of amplified DNA probe systems for infectious testing in clinical
diagnostic laboratories. Previously, Dr. Burke held numerous management and
research positions at Molecular Devices Corporation, Allied Signal, Health and
Scientific Products Division, and Abbott Laboratories, Diagnostics Division.

Wallace G. Dempsey has been a director of the Company since February 1986.
From 1973 until May 1993, he served as the Secretary and General Attorney of
International Flavors & Fragrances, Inc. From May 1993 until April 1994, Mr.
Dempsey served as a consultant to International Flavors & Fragrances, Inc.

Irwin J. Gruverman has been a director of the Company since November 1990.
Since 1982, Mr. Gruverman has been Chairman of the Board and Chief Executive
Officer of Microfluidics International and its predecessor, Biotechnology
Development Corp. Since 1990, he has also been a General Partner of G&G
Diagnostics Funds which invests in medical diagnostics companies. Mr. Gruverman
is also a director of Fiberchem International, Inc., InVitro International and
North American Scientific, Inc.

Hayden H. Harris has been a director of the Company since March 1993 and
Chairman of the Board since November 1995. Since 1977, Mr. Harris has been
President and a director of Enterprise Management, Inc., a venture capital
management and consulting company. From 1990 to present, Mr. Harris has been
Chairman of the Board and Chief Executive Officer of Software Services
Corporation, a provider of contract software services, and since 1995 he has
served as President and a director of EDM, Inc., a venture capital management
company.

Wolfgang Woloszczuk, Ph.D. has been a director of the Company since November
1990. Dr. Woloszczuk has also served as Chief Executive Officer of Biomedica
GmbH since 1992 and of Biocis Handels GmbH since 1994. He has also served as an
executive officer of Bionova Handels GmbH since 1988. Dr. Woloszczuk was an
executive officer of Biozol Diagnostica Vertriebs GmbH from 1989 until May 1996.
Since November 1997, Dr. Woloszczuk has been President of BioNet, Inc., an
exporter of biomedical products located in Southbridge, Massachusetts. In
addition, Dr. Woloszczuk has been a Professor of medicinal chemistry at the
University of Vienna since 1989.

FAMILY RELATIONSHIPS

Wallace G. Dempsey is the father of Owen A. Dempsey. There are no other
family relationships among directors or executive officers of the Company.

THE BOARD OF DIRECTORS AND ITS COMMITTEES

The Board of Directors met 15 times during the fiscal year ended May 31,
1999. The Board of Directors has an Audit Committee, of which Irwin Gruverman
and Hayden Harris are members. The Audit Committee oversees the accounting and
tax functions of the Company, including matters relating to the appointment and
activities of the Company's independent auditors. The Audit Committee met two
times during the fiscal year ended May 31, 1999. The Board of Directors also has
a Compensation Committee, of which Hayden Harris, Charles Burke and Wolfgang
Woloszczuk are members. The Compensation Committee reviews and makes
recommendations concerning executive compensation, and administers the Company's
1992 Stock Plan (the "1992 PLAN") together with the Board of Directors. The

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Compensation Committee also administers the Company's 1993 Non-Employee Director
Stock Option Plan (the "DIRECTOR PLAN"). The Compensation Committee met five
times during the fiscal year ended May 31, 1999. The Board of Directors does not
currently have a standing executive or nominating committee. Each of the
Company's directors attended at least 75% of the aggregate of the total number
of meetings of the Board of Directors and of all Committees on which he served
during the fiscal year ended May 31, 1999.

COMPENSATION AND OTHER INFORMATION
CONCERNING DIRECTORS AND OFFICERS

EXECUTIVE COMPENSATION

The following table summarizes the compensation paid or accrued by the
Company for services rendered for its fiscal year ended May 31, 1999 to Owen A.
Dempsey, the Company's President and Chief Executive Officer, Dennis H.
Walczewski, the Company's Vice President of Sales and Avery W. Catlin, the
Company's Vice President, Operations and Finance, Chief Financial Officer,
Treasurer and Clerk (the "NAMED OFFICERS"). No other executive officer earned a
total salary and bonus exceeding $100,000 during the fiscal year ended May 31,
1999. The Company did not grant to the Named Officers any restricted stock
awards or stock appreciation rights ("SARS") and did not make any long-term
incentive plan payouts during the fiscal years ended May 31, 1997, 1998 and
1999.

LONG TERM COMPENSATION
----------------------------------------

ANNUAL COMPENSATION AWARDS PAYOUTS
------------------------ ------------------- -------------------

SECURITIES
UNDERLYING ALL OTHER
NAME AND PRINCIPAL POSITION YEAR SALARY ($) BONUS ($)(1) OPTIONS (#) COMPENSATION ($)(2)
- -------------------------------------------- --------- ---------- ------------ ------------------- -------------------

Owen A. Dempsey............................. 1999 $ 131,700 $ 32,320 30,000 $ --
President and Chief Executive 1998 120,000 31,067 -- 975
Officer 1997 107,692 49,913 200 --
Avery W. Catlin............................. 1999 $ 132,923 $ 22,734 20,000 $ 1,243
Vice President, Operations and 1998 124,885 20,695 12,000 1,566
Finance, Chief Financial Officer, 1997 71,285 16,819 60,200 --
Treasurer and Clerk (3)
Dennis H. Walczewski........................ 1999 $ 108,538 $ 29,495 14,000 $ 2,009
Vice President of Sales 1998 90,000 29,825 12,000 1,344
1997 90,000 47,350 200 --

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

(1) Amounts included in "Bonus" for Fiscal Year 1999 are target amounts only.
Fiscal Year 1999 ended on May 31, 1999 and information needed to calculate
actual bonus amounts for Fiscal Year 1999 was therefore not available in
time for this filing. All bonus amounts included in Fiscal Year 1998 and
Fiscal Year 1997 are actual amounts based on service during such fiscal
year, although paid in the subsequent fiscal year.

(2) Company contributions to its 401(k) plan.

(3) Mr. Catlin joined the Company as Vice President, Finance, Chief Financial
Officer, Treasurer and Clerk in December 1996.

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OPTIONS

The following table sets forth certain information concerning stock options
granted during the fiscal year ended May 31, 1999 to the Named Officers.

OPTIONS GRANTED IN THE LAST FISCAL YEAR(1)

INDIVIDUAL GRANTS

NUMBER OF
SECURITIES
UNDERLYING OPTIONS % OF TOTAL OPTIONS GRANTED TO EXERCISE PRICE EXPIRATION
NAME GRANTED(2) EMPLOYEES IN FISCAL YEAR(3) ($/SHARE) DATE
- ----------------------------------- ------------------- --------------------------------- --------------- -----------

Owen A. Dempsey.................... 30,000 14% $ 3.81 6/24/08
Avery W. Catlin.................... 20,000 10% $ 3.81 6/24/08
Dennis H. Walczewski............... 14,000 7% $ 3.81 6/24/08

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

(1) The Company did not grant any SAR's during the fiscal year ended May 31,
1999.

(2) Stock options were granted under the 1992 Plan at an exercise price equal to
the fair market value of the Company's common stock on the date of grant.
The options have a term of ten years from the date of grant and become
exercisable as to 25% of the shares covered on each of the first four
anniversaries of the date of grant.

(3) Represents all options granted to Mr. Dempsey, Mr. Catlin and Mr. Walczewski
during fiscal year ended May 31, 1999, respectively, as a percentage of the
total options granted to employees and consultants during the same period. A
total of 209,000 options were granted to employees and consultants in fiscal
year 1999.

The following table sets forth certain information concerning stock options
held by the Named Officers on May 31, 1999.

AGGREGATED OPTION EXERCISES IN LAST FISCAL YEAR
AND FISCAL YEAR-END OPTION VALUES(1)

VALUE OF
NUMBER OF SECURITIES UNEXERCISED
UNDERLYING IN-THE-MONEY
UNEXERCISED OPTIONS
OPTIONS AT MAY 31,
AT MAY 31, 1999(#) 1999($)(2)
-------------------------- -----------

SHARES ACQUIRED VALUE
NAME ON EXERCISE(#) REALIZED($) EXERCISABLE UNEXERCISABLE EXERCISABLE
- ------------------------------------- ------------------- --------------- ----------- ------------- -----------
Owen A. Dempsey...................... -- -- 88,200 36,000 $ 96,875
Avery W. Catlin...................... -- -- 33,200 59,000 --
Dennis H. Walczewski................. -- -- 28,700 31,500 --

NAME UNEXERCISABLE
- ------------------------------------- -----------------
Owen A. Dempsey...................... --
Avery W. Catlin...................... --
Dennis H. Walczewski................. --

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

(1) The Company has never granted any SARs.

(2) Value is based on the difference between the option exercise price and
$3.56, the fair market value of the Company's Common Stock on May 28, 1999,
the last trading day for the fiscal year ended May 31, 1999, multiplied by
the number of shares of Common Stock underlying the options.

COMPENSATION OF DIRECTORS

Each non-employee director of the Company is entitled to $500, plus all
reasonable expenses, for each meeting of the Company's Board of Directors and
each Committee meeting that he attends. In addition,

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pursuant to the Director Plan, each non-employee director is automatically
granted, without further action by the Board, an option to purchase 6,000 shares
of the Company's Common Stock upon (a) the date such director is first elected
to the Board and (b) each subsequent anniversary of that director's election to
the Board. The exercise price per share of all options granted under the
Director Plan is equal to 100% of the fair market value of the Company's Common
Stock on the date such options are granted. Options granted under the Director
Plan are exercisable as to one-third of the shares subject to such option on the
date of grant and as to an additional one-third of the shares subject to the
option on each successive anniversary of the date of grant, provided that the
optionee has continuously served as a member of the Board of Directors through
such date. Notwithstanding the foregoing, those options, which were granted
under the Director Plan on November 12, 1993, were fully vested and exercisable
in full on the date of such grant.

The Chairman of the Company's Board of Directors, Hayden Harris, is entitled
to an additional $500 per meeting of the Board of Directors and $1,000 per day
for each meeting with the Company's President and Chief Executive Officer that
is not a Board or Committee meeting. Moreover, in addition to his annual option
grant under the Director Plan, the Chairman also received an option to purchase
6,000 shares of the Company's Common Stock pursuant to the 1992 Plan. These
options were granted at an exercise price equal to 100% of the fair market value
of the Company's Common Stock as of the date of grant. Provided that the
Chairman continues to serve the Company in the capacity of employee, officer,
director or consultant, the options shall vest over a period of one year from
the date of grant, in four equal quarterly installments.

Pursuant to a letter, dated as of July 2, 1998, from the Company to Charles
R. Burke, Ph.D., a director of the Company, Dr. Burke is entitled to the same
compensation paid to all non-employee directors of the Company, and is also
entitled to receive $500 per half-day meeting with the Company's President and
Chief Executive Officer which is not a Board or Committee meeting and an option
to purchase 6,000 shares of the Company's Common Stock pursuant to the 1992
Plan. These options were granted at an exercise price equal to 100% of the fair
market value of the Company's Common Stock as of the date of grant. One-third of
these options vested on the date of grant and, provided that Dr. Burke continues
to serve the Company in the capacity of employee, officer, director or
consultant, the balance of the options shall vest over a period of two years, in
two equal annual installments.

Directors who are employees of the Company receive no additional
compensation for serving on the Board of Directors or its Committees.

EXECUTIVE EMPLOYMENT AGREEMENTS

On December 4, 1996, the Company entered into an employment agreement with
Avery W. Catlin pursuant to which he joined the Company (the "CATLIN
AGREEMENT"). Under the terms of the Catlin Agreement, Mr. Catlin is entitled to
receive a minimum salary of $120,000 and a minimum bonus of $34,000 for the
first year of the term and a minimum salary of $130,000 for the second year of
the term. Mr. Catlin's bonus after the first year of the term will be based on
formulas agreed to by the Company and Mr. Catlin. Mr. Catlin's salary after the
second year of the term will be determined by the Board of Directors.
Additionally, Mr. Catlin is eligible for participation in an executive incentive
pay plan and in all of the Company's welfare, benefit, retirement and savings
plans on the same basis as other employees of the Company. Pursuant to the
Catlin Agreement, and subject to the terms of a stock option agreement, Mr.
Catlin received an option to purchase 60,000 shares of Common Stock at $3.88 per
share, vesting at 25% per annum for four years. Mr. Catlin's employment by the
Company may be terminated, with or without cause, by either party upon prior
written notice. In the event Mr. Catlin is terminated by the Company other than
for cause or the death of Mr. Catlin, Mr. Catlin would be entitled to continue
receiving his salary and benefits for a period of six months following his
termination date. In the event Mr. Catlin is terminated by the Company without
cause, all of the outstanding options which have been granted to Mr. Catlin, but
which have not vested, shall vest immediately and be exercisable in full. In the
event Mr. Catlin is terminated pursuant to a change in control of the Company,
as defined in the Catlin

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Agreement, Mr. Catlin would be entitled to receive a cash payment equal to his
annual salary on the date of termination and all of the outstanding options
which have been granted to Mr. Catlin, but which have not yet vested, shall vest
immediately and be exercisable in full. The initial term of the Catlin Agreement
is three years and may be automatically renewed for one year periods.

Pursuant to a letter agreement, dated as September 11, 1998, between the
Company and Christine A. Burns, Ph.D., the Company's Vice President--Product
Development and Technology, during the first year of Dr. Burns' employment her
annual base salary is set at $128,000 and her annual incentive pay was set at a
maximum of $24,000. During the second year of Dr. Burns' employment her annual
base salary will be increased to $144,000 and her incentive pay will be set at a
maximum of $24,000. In addition, if, through no fault of her own, Dr. Burns'
employment with the Company is terminated, she shall be entitled to a severance
package in the form of salary continuation for a period of six months from her
last date of employment, at the rate of her then current base salary, and
medical benefits will also be continued for up to six months.

CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

On January 15, 1999, the Company entered into a distribution agreement with
Biozol Diagnostica Vertrieb GmbH ("BIOZOL") pursuant to which Biozol is the
exclusive distributor of the Company's products in Germany.

On January 29, 1999, the Company entered into a distribution agreement with
Biomedica pursuant to which Biomedica distributes the Company's products in
certain European countries.

Wolfgang Woloszczuk, a director of the Company, is currently an executive
officer and 20% shareholder of Biomedica, a 50% owner of Biozol.

STOCK OPTION ACCELERATION AND CASHOUT

Pursuant to the Company's 1992 Plan and the option agreements issued
thereunder, upon the consummation of the Offer the holders of stock options
granted under the 1992 Plan, including the executive officers of the Company and
participating directors, will receive a cash payment in connection with the
cancellation of their options. The cash payment for each option that has an
exercise price that is lower than the Offer Price will equal the difference
between the Offer Price and the exercise price of such option, multiplied by the
number of Shares subject to such option (whether vested or unvested). The
Company will make aggregate payments equal to approximately $401,390. Of that
total, Mr. Owen A. Dempsey will receive approximately $110,000 and Dr. Burns
will receive approximately $60,000. The Company will make aggregate payments to
non-employee directors under the 1992 Plan in the amount of $12,420. Of that
total, Mr. Harris will receive approximately $7,200 and Dr. Burke will receive
approximately $5,220.

Non-employee directors of the Company holding stock options granted pursuant
to the Director Plan will receive a cash payment in connection with the
cancellation of their options. The cash payment for each option that has an
exercise price that is lower than the Offer Price will equal the difference
between the Offer Price and the exercise price of such option, multiplied by the
number of vested (but not unvested)

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Shares subject to such option. The Company will make aggregate payments equal to
approximately $40,520. Of that total, Mr. Wallace Dempsey will receive
approximately $19,880; Mr. Hayden Harris will receive approximately $19,880; Mr.
Irwin Gruverman will receive approximately $380; and Dr. Wolfgang Woloszczuk
will receive approximately $380.

SECTION 16(A) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

Section 16(a) of the Securities Exchange Act of 1934, as amended, requires
the Company's directors, executive officers and holders of more than 10% of the
Company's Common Stock (collectively, "REPORTING PERSONS") to file with the SEC
initial reports of ownership and reports of changes in ownership of Common Stock
of the Company. Such persons are required by regulations of the SEC to furnish
the Company with copies of all such filings. Based on its review of the copies
of such filings received by it with respect to the fiscal year ended May 31,
1999, the Company believes that all Reporting Persons complied with the Section
16(a) filing requirements in the fiscal year ended May 31, 1999 with the
following exception: Dr. Burke, a director of the Company, had one late report
concerning one transaction.

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ADAMS, HARKNESS & HILL, INC. ANNEX B

May 27, 1999
Board of Directors
Endogen, Inc.
30 Commerce Way
Woburn, MA 01801

Attention: Hayden Harris, Chairman of the Board

Members of the Board:

You have requested our opinion (the "Fairness Opinion") as to the fairness,
from a financial point of view, to the holders of common stock (the "Common
Stock"), of Endogen, Inc. (the "Company") of the consideration to be received by
holders of Common Stock, pursuant to an Agreement and Plan of Merger dated as of
May 27, 1999 (the "Agreement") among the Company, PerBio Science AB (the
"Parent"), and Ewok Acquisition Corp. (the "Purchaser"), a wholly owned
subsidiary of the Parent. The Agreement provides for (i) the commencement by
Purchaser of a tender offer (the "Tender Offer") to purchase all of the
outstanding shares of Common Stock at a price of $3.75 per share, net to the
seller in cash (the "Offer Price"), and (ii) the subsequent merger (the
"Merger") of the Purchaser into the Company, in which the remaining shares of
Common Stock will be converted and exchanged for an amount equal to the Offer
Price at the Effective Time. The Tender Offer and the Merger are collectively
referred to as the "Transaction." The terms and conditions of the Transaction
are more fully set forth in the Agreement.

Adams, Harkness & Hill, Inc., as part of its investment banking activities,
is continually engaged in the valuation of businesses and their securities in
connection with mergers and acquisitions, negotiated underwritings, secondary
distributions of listed and unlisted securities, private placements and
valuations for corporate and other purposes. We have acted as financial advisor
to the Company in connection with the Agreement and will receive a fee for
services, which is contingent upon consummation of the Transaction. We will also
receive a fee for providing the Fairness Opinion that is not contingent upon the
consummation of the Transaction.

We are expressing no opinion as to the value of the Common Stock either now,
upon consummation of the Transaction, or at any other time. Our Fairness Opinion
as expressed herein is limited to the fairness, from a financial point of view,
of the consideration to be received by holders of the Common Stock as of the day
hereof and does not address the Company's underlying business decision to engage
in the Agreement.

In developing our Fairness Opinion, we have, among other things: (i)
reviewed the information contained in the Company's Annual Report, Form 10-KSB,
and related financial information for the fiscal year ended May 31, 1998, and
the Company's Form 10-QSB and the related unaudited financial information for
the nine month period ended February 28, 1999; (ii) analyzed and discussed
certain financial statements and other financial and operating data concerning
the Company, including forecasts, prepared by members of the senior management
of the Company; (iii) conducted due diligence discussions with members of senior
management of the Company; (iv) reviewed the historical market prices and
trading activity for the Common Stock and compared them with those of certain
publicly traded companies we deem to be relevant and comparable to the Company;
(v) reviewed the historical market prices for the Common Stock and compared them
with those of certain market indices we deem to be relevant; (vi) compared the
results of operations of the Company with those of certain companies we deem to
be relevant and comparable to the Company; (vii) compared the financial terms of
the Agreement with the financial terms of certain other mergers and acquisitions
to the extent we deemed them to be relevant and comparable to the Agreement;
(viii) participated in certain discussions among representatives of the

B-1

Company and their financial and legal advisors; (ix) reviewed such other
financial studies and analyses and performed such other investigations and took
into account such other matters as we deemed necessary, including our assessment
of general economic, market and monetary conditions as of the date hereof.

In connection with our review and arriving at our Fairness Opinion, we have
not independently verified any information received from the Company, have
relied on such information, and have assumed that all such information is
complete and accurate in all material respects. With respect to any forecasts
reviewed relating to the prospects of the Company, we have assumed that they
have been reasonably prepared on bases reflecting the best currently available
estimates and judgments of Company management as to the future financial
performance of the Company. Our Fairness Opinion is rendered on the basis of
securities market conditions prevailing as of the date hereof and on the
conditions and prospects, financial and otherwise, of the Company as known to us
on the date hereof. We have not conducted, nor have we received copies of, any
independent valuation or appraisal of any of the assets of the Company. In
addition, we have assumed, with your consent, that any material liabilities
(contingent or otherwise, known or unknown) of the Company are as set forth in
the consolidated financial statements of the Company.

This opinion is necessarily based upon the information available to us and
facts and circumstances as they exist and are subject to evaluation on the date
hereof; events occurring after the date hereof could materially affect the
assumptions used in preparing this opinion. We are not expressing any opinion
herein as to the price at which shares of Common Stock have traded or may trade
at any future time. We have not undertaken to reaffirm or revise this opinion or
otherwise comment upon any events occurring after the date hereof and do not
have any obligation to update, revise or reaffirm this opinion.

This opinion is directed to the Board of Directors of the Company and is not
intended to be and does not constitute a recommendation to any stockholder of
the Company. We were not requested to opine as to, and this opinion does not
address, the basic business decision to proceed with or effect the Transaction.
It is understood that this letter is for the information of the Board of
Directors of the Company and may not be used for any other purpose without our
prior written consent, except that this opinion may be included in its entirety
in filing with the Securities and Exchange Commission, the Schedule 14D-9
relating to the Tender Offer or the prospectus/proxy statement relating to the
Merger. Based upon and subject to the foregoing, it is our opinion that, as of
the date hereof, the consideration is fair, from a financial point of view, to
the Company and the Company's stockholders.

Sincerely,

ADAMS, HARKNESS & HILL, INC.

/s/ GREGORY B. BROWN
------------------------------
Gregory B. Brown
MANAGING DIRECTOR
By:

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