EXHIBIT 4.2


                    Dade International Inc.

                         $350,000,000

          11 1/8% Senior Subordinated Notes due 2006

                      PURCHASE AGREEMENT
                      ------------------


                                                 April 30, 1996


BT SECURITIES CORPORATION
CS FIRST BOSTON CORPORATION
MORGAN STANLEY & CO. INCORPORATED
c/o BT Securities Corporation
One Bankers Trust Plaza
130 Liberty Street
New York, New York  10006


Ladies and Gentlemen:

          Dade International Inc., a Delaware corporation (the
"Company"), hereby confirms its agreement with you (the
 -------
"Initial Purchasers"), as set forth below.
 ------------------
          1.   The Securities.  Subject to the terms and
               --------------
conditions herein contained, the Company proposes to issue and
sell to the Initial Purchasers $350,000,000 aggregate principal
amount of its 11 1/8% Senior Subordinated Notes due 2006 (the
"Notes").  The Notes are to be issued under an indenture (the
 -----
"Indenture") to be dated as of May 7, 1996 between the Company
 ---------
and IBJ Schroder Bank & Trust Company, as trustee (the
"Trustee").
 -------
          On April 9, 1996, an offer, as supplemented on
April 26, 1996 (the "Tender Offer"), was commenced to purchase
                     ------------
for cash up to all (but not less than a majority in principal
amount outstanding) of the Company's 13% Senior Subordinated
Notes due 2005 (the "Old Notes") and a related solicitation
                     ---------
(the "Consent Solicitation") of consents to modify certain
      --------------------
terms of the indenture under which the Old Notes were issued
(the "Old Notes Indenture").  In connection therewith, the
      -------------------
Company and IBJ Schroder Bank & Trust Company, as trustee (the
"Old Notes Trustee"), will execute a supplemental indenture
 -----------------

 
                                      -2-



(the "Supplemental Indenture") giving effect to the proposed
      ----------------------
amendments to the Old Notes Indenture.

            The Notes are being issued and sold in connection
with the acquisition by the Company (the "Acquisition") of the
                                          -----------
in vitro diagnostics business of E.I. du Pont de Nemours and
Company and its affiliates ("DuPont"), pursuant to an Asset
                             ------
Purchase and Sale Agreement (the "Asset Purchase Agreement")
                                  ------------------------
dated December 11, 1995 between the Company and DuPont.  All
references herein to the "IVD Business" refer to the Business
                          ------------
Assets (as defined in the Asset Purchase Agreement) to be
purchased from DuPont pursuant to the Asset Purchase Agreement.

            The Acquisition and the ongoing working capital needs
of the Company will be financed by:  (i) the issuance of the
Notes and (ii) the incurrence by the Company and its
subsidiaries of senior secured bank financing pursuant to a
credit agreement (together with all documents executed in
connection therewith, the "Credit Agreement") among the
                           ----------------
Company, Diagnostics Holding, Inc. ("Holdings"), Bankers Trust
                                     --------
Company, as agent, and certain financial institutions party
thereto in the form of (A) a multiple tranche term loan
facility in the amount of $460 million and (B) a revolving
credit facility for working capital purposes in the amount of
$50 million.

            The Notes will be offered and sold to the Initial
Purchasers without being registered under the Securities Act of
1933, as amended (the "Act"), in reliance on one or more
                       ---
exemptions therefrom.

            In connection with the sale of the Notes, the Company
has prepared a preliminary offering memorandum dated April 11,
1996 (the "Preliminary Memorandum") and a final offering
           ----------------------
memorandum dated April 30, 1996 (the "Final Memorandum"; the
                                      ----------------
Preliminary Memorandum and the Final Memorandum each herein
being referred to as a "Memorandum"), each setting forth or
                        ----------
including a description of the terms of the Notes and the
offering, a description of the Acquisition of the transactions
contemplated thereby and hereby, a description of the Company
and the IVD Business and any material developments relating to
the Company and the IVD Business occurring after the date of
the most recent historical financial statements included
therein.

            The Initial Purchasers and their direct and indirect
transferees of the Notes will be entitled to the benefits of
the Registration Rights Agreement, substantially in the form
attached hereto as Exhibit A (the "Registration Rights
                   ---------       -------------------

 
                                      -3-

Agreement"), pursuant to which the Company has agreed, among
- ---------
other things, to file a registration statement (the
"Registration Statement") with the Securities and Exchange
 ----------------------
Commission (the "Commission") registering the Exchange Notes
                 ----------
(as defined therein) or, in certain cases, the Notes under the
Act.

            2.    Representations and Warranties.  The Company
                  ------------------------------
represents and warrants to and agrees with each of the Initial
Purchasers that:

            (a)  Neither the Preliminary Memorandum as of the
date thereof nor the Final Memorandum nor any amendment or
supplement thereto as of the date thereof and at all times
subsequent thereto up to the Closing Date (as defined in
Section 3 below) contained or contains any untrue statement of
a material fact or omitted or omits to state a material fact
necessary to make the statements therein, in the light of the
circumstances under which they were made, not misleading,
except that the representations and warranties set forth in
this Section 2(a) do not apply to statements or omissions made
in reliance upon and in conformity with information relating to
any of the Initial Purchasers furnished to the Company in
writing by BT Securities Corporation, on behalf of any of the
Initial Purchasers, expressly for use in the Preliminary
Memorandum, the Final Memorandum or any amendment or supplement
thereto.

            (b)  As of the Closing Date, the Company will have
the capitalization set forth in the Final Memorandum; all of
the subsidiaries of the Company (which includes any
subsidiaries of the Company that have been formed to consummate
the Acquisition) are listed on Schedule 2 attached hereto
                               ----------
(each, a "Subsidiary" and collectively, the "Subsidiaries");
          ----------                         ------------
all of the outstanding shares of capital stock of the Company
and the Subsidiaries have been, and as of the Closing Date will
be, duly authorized and validly issued, are fully paid and
nonassessable and were not issued in violation of any
preemptive or similar rights; except as set forth in the Final
Memorandum, all of the outstanding shares of capital stock of
the Company and of each of the Subsidiaries will be free and
clear of all liens, encumbrances, equities and claims or
restrictions on transferability (other than those imposed by
the Act and the securities or "Blue Sky" laws of certain
jurisdictions) or voting; except as set forth in the Final
Memorandum, there are no (i) options, warrants or other rights
to purchase, (ii) agreements or other obligations to issue or
(iii) other rights to convert any obligation into, or exchange
any securities for, shares of capital stock of or ownership
interests in the Company or any of the 

 
                                      -4-

Subsidiaries outstanding. Except for the Subsidiaries or as 
disclosed in the Final Memorandum, the Company does not own, 
directly or indirectly, any material amount of capital stock 
or any other equity or long-term debt securities or have any 
equity interest in any firm, partnership, joint venture or 
other entity other than Sunol Molecular Corporation and 
Spectral Diagnostics Inc.

            (c)  Each of the Company and the Subsidiaries has
been duly incorporated, is validly existing and is in good
standing as a corporation under the laws of its jurisdiction of
incorporation, with all requisite corporate power and authority
to own its properties and conduct its business as now
conducted, and as described in the Final Memorandum; each of
the Company and the Subsidiaries is, and upon consummation of
the Acquisition will be, duly qualified to do business as a
foreign corporation in good standing in all other jurisdictions
where the ownership or leasing of its properties or the conduct
of its business requires such qualification, except where the
failure to be so qualified would not, individually or in the
aggregate, have a material adverse effect on the general
affairs, management, business, condition (financial or
otherwise), prospects or results of operations of the Company
and the Subsidiaries, taken as a whole, or the IVD Business
(any such event, a "Material Adverse Effect").
                    -----------------------

            (d)  The Company has all requisite corporate power
and authority to execute, deliver and perform each of its
obligations under the Notes, the Exchange Notes and the Private
Exchange Notes (as defined in the Registration Rights
Agreement).  The Notes, the Exchange Notes and the Private
Exchange Notes have each been duly and validly authorized by
the Company and, when executed by the Company and authenticated
by the Trustee in accordance with the provisions of the
Indenture and, in the case of the Notes, when delivered to and
paid for by the Initial Purchasers in accordance with the terms
of this Agreement, will have been duly executed, issued and
delivered and will constitute valid and legally binding
obligations of the Company, entitled to the benefits of the
Indenture and enforceable against the Company in accordance
with their terms, except that the enforcement thereof may be
subject to (i) bankruptcy, insolvency, reorganization,
moratorium or other similar laws now or hereafter in effect
relating to creditors' rights generally, and (ii) general
principles of equity and the discretion of the court before
which any proceeding therefor may be brought.

 
                                      -5-

            (e)  The Company has all requisite corporate power
and authority to execute, deliver and perform its obligations
under the Indenture.  The Indenture meets the requirements for
qualification under the Trust Indenture Act of 1939, as amended
(the "TIA").  The Indenture has been duly and validly
      ---
authorized by the Company and, when executed and delivered by
the Company (assuming the due authorization, execution and
delivery by the Trustee), will constitute a valid and legally
binding agreement of the Company, enforceable against the
Company in accordance with its terms, except that the
enforcement thereof may be subject to (i) bankruptcy,
insolvency, reorganization, moratorium or other similar laws
now or hereafter in effect relating to creditors' rights
generally and (ii) general principles of equity and the
discretion of the court before which any proceeding therefor
may be brought.

            (f)  The Company has all requisite corporate power
and authority to execute, deliver and perform its obligations
under the Registration Rights Agreement.  The Registration
Rights Agreement has been duly and validly authorized by the
Company and, when executed and delivered by the Company, will
constitute a valid and legally binding agreement of the
Company, enforceable against the Company in accordance with its
terms, except that (A) the enforcement thereof may be subject
to (i) bankruptcy, insolvency, reorganization, moratorium or
other similar laws now or hereafter in effect relating to
creditors' rights generally and (ii) general principles of
equity and the discretion of the court before which any
proceeding therefor may be brought and (B) any rights to
indemnity or contribution thereunder may be limited by federal
and state securities laws and public policy considerations.

            (g)  The Company has all requisite corporate power
and authority to execute, deliver and perform its obligations
under this Agreement and to consummate the transactions
contemplated hereby.  This Agreement has been duly and validly
authorized, executed and delivered by the Company.  

            (h)  The Company has delivered to the Initial
Purchasers a true, correct and complete executed copy of the
Asset Purchase Agreement, together with any amendments thereto.
The Company has all requisite corporate power and authority to
enter into the Asset Purchase Agreement and the Company has all
requisite corporate power and authority to consummate the
transactions contemplated thereby.  The Asset Purchase
Agreement has been duly authorized, executed and delivered by
the Company.  Each of the representations and warranties of the

 
                                      -6-

Company set forth in the Asset Purchase Agreement is true in
all material respects as of the date hereof.

            (i)  No consent, approval, authorization or order of
any court or governmental agency or body or third party is
required for the performance of this Agreement or the Asset
Purchase Agreement by the Company or the consummation by the
Company of the transactions contemplated hereby or thereby,
except such as have been obtained and such as may be required
under state securities or "Blue Sky" laws in connection with
the purchase and resale of the Notes by the Initial Purchasers.
None of the Company or the Subsidiaries is, or upon
consummation of the Acquisition will be, (i) in violation of
its certificate of incorporation or bylaws (or similar
organizational document), (ii) in breach or violation of any
statute, judgment, decree, order, rule or regulation applicable
to any of them or any of their respective properties or assets,
except for any such breach or violation which would not,
individually or in the aggregate, have a Material Adverse
Effect, or (iii) in breach of or default under (nor has any
event occurred which, with notice or passage of time or both,
would constitute a default under) or in violation of any of the
terms or provisions of any indenture, mortgage, deed of trust,
loan agreement, note, lease, license, franchise agreement,
permit, certificate, contract or other agreement or instrument
to which any of them is a party or to which any of them or
their respective properties or assets is subject (collectively,
"Contracts"), except for any such breach, default, violation or
 ---------
event which would not, individually or in the aggregate, have a
Material Adverse Effect.

            (j)  The execution, delivery and performance by the
Company of this Agreement, the Indenture, the Registration
Rights Agreement and the Asset Purchase Agreement and the
consummation by the Company of the transactions contemplated
hereby and thereby, and the fulfillment of the terms hereof and
thereof, will not conflict with or constitute or result in a
breach of or a default under (or an event which with notice or
passage of time or both would constitute a default under) or
violation of any of (i) the terms or provisions of any
Contract, except for any such conflict, breach, violation,
default or event which would not, individually or in the
aggregate, have a Material Adverse Effect, (ii) the certificate
of incorporation or bylaws (or similar organizational document)
of the Company or any of the Subsidiaries, or (iii) (assuming
compliance with all applicable state securities or "Blue Sky"
laws and assuming the accuracy of the representations and
warranties 

 
                                      -7-

of the Initial Purchasers in Section 8 hereof) any
statute, judgment, decree, order, rule or regulation applicable
to the Company or any of the Subsidiaries or any of their
respective properties or assets, except for any such conflict,
breach or violation which would not, individually or in the
aggregate, have a Material Adverse Effect.

            (k)  The audited consolidated financial statements of
the Company and, to the knowledge of the Company after due
inquiry, the IVD Business included in the Final Memorandum
present fairly in all material respects the financial position,
results of operations and cash flows of the Company and the IVD
Business, respectively, at the dates and for the periods to
which they relate and have been prepared in accordance with
generally accepted accounting principles applied on a
consistent basis, except as otherwise stated therein.  The
summary and selected financial and statistical data in the
Final Memorandum present fairly in all material respects the
information shown therein and the summary and selected
financial data have been prepared and compiled on a basis
consistent with the audited financial statements included
therein, except as otherwise stated therein.  Price Waterhouse
LLP (the "Independent Accountants") is an independent public
          -----------------------
accounting firm within the meaning of the Act and the rules and
regulations promulgated thereunder.

            (l)  The pro forma financial statements (including
the notes thereto) and the other pro forma financial
information included in the Final Memorandum (i) comply as to
form in all material respects with the applicable requirements
of Regulation S-X promulgated under the Securities Exchange Act
of 1934, as amended (the "Exchange Act"), (ii) have been
                          ------------
prepared in accordance with the Commission's rules and
guidelines with respect to pro forma financial statements, and
(iii) have been properly computed on the bases described
therein; the assumptions used in the preparation of the pro
forma financial data and other pro forma financial information
included in the Final Memorandum are reasonable and the
adjustments used therein are appropriate to give effect to the
transactions or circumstances referred to therein.

            (m)  Other than as described in the Memorandum under
the captions "Legal Proceedings," "Environmental, Health and
Safety Matters" and "Intellectual Property," there is not
pending or, to the knowledge of the Company, threatened any
action, suit, proceeding, inquiry or investigation to which the
Company, any of the Subsidiaries or the IVD Business is a
party, 

 
                                      -8-

or to which the property or assets of the Company, any
of the Subsidiaries or the IVD Business are subject, before or
brought by any court, arbitrator or governmental agency or body
which, if determined adversely to the Company, any of the
Subsidiaries or the IVD Business, would, individually or in the
aggregate, have a Material Adverse Effect or which seeks to
restrain, enjoin, prevent the consummation of or otherwise
challenge the issuance or sale of the Notes to be sold
hereunder or the consummation of the other transactions
described in the Final Memorandum.

            (n)  Each of the Company, the Subsidiaries and, to
the knowledge of the Company after due inquiry, DuPont with
respect to the IVD Business owns or possesses, and upon
consummation of the  Acquisition the Company and the
Subsidiaries will own or possess, adequate licenses or other
rights to use all patents, trademarks, service marks, trade
names, copyrights and know-how necessary to conduct the
businesses now or proposed to be operated by it as described in
the Final Memorandum, and none of the Company, the Subsidiaries
or, to the knowledge of the Company after due inquiry, DuPont
with respect to the IVD Business has received any notice of
infringement of or conflict with (or knows of any such
infringement of or conflict with) asserted rights of others
with respect to any patents, trademarks, service marks, trade
names, copyrights or know-how which, if such assertion of
infringement or conflict were sustained, would, individually or
in the aggregate, have a Material Adverse Effect.

            (o)  Each of the Company, the Subsidiaries and, to
the knowledge of the Company after due inquiry, DuPont with
respect to the IVD Business possesses, and upon consummation of
the Acquisition the Company and the Subsidiaries will possess,
all licenses, permits, certificates, consents, orders,
approvals and other authorizations from, and has made or will
have made all declarations and filings with, all federal,
state, local and other governmental authorities, all self-
regulatory organizations and all courts and other tribunals,
presently required or necessary to own or lease, as the case
may be, and to operate its respective properties and to carry
on its respective businesses as now or proposed to be conducted
as set forth in the Final Memorandum ("Permits"), except where
                                       -------
the failure to obtain such Permits would not, individually or
in the aggregate, have a Material Adverse Effect; each of the
Company, the Subsidiaries and, to the knowledge of the Company
after due inquiry, DuPont with respect to the IVD Business has
fulfilled and performed all of its obligations with respect to

 
                                      -9-

such Permits and no event has occurred which allows, or after
notice or lapse of time would allow, revocation or termination
thereof or results in any other material impairment of the
rights of the holder of any such Permit; and none of the
Company, the Subsidiaries or, to the knowledge of the Company
after due inquiry, DuPont with respect to the IVD Business has
received any notice of any proceeding relating to revocation or
modification of any such Permit, except as described in the
Final Memorandum and except where such revocation or
modification would not, individually or in the aggregate, have
a Material Adverse Effect.

            (p)  Since the date of the most recent financial
statements appearing in the Final Memorandum, except as
described therein, (i) none of the Company, the Subsidiaries or
to the knowledge of the Company, the IVD Business has incurred
any liabilities or obligations, direct or contingent, or
entered into or agreed to enter into any transactions or
contracts (written or oral) not in the ordinary course of
business which liabilities, obligations, transactions or
contracts would, individually or in the aggregate, be material
to the general affairs, management, business, condition
(financial or otherwise), prospects or results of operations of
the Company and the Subsidiaries, taken as a whole, or the IVD
Business (a "Material Change"), (ii) none of the Company or the
             ---------------
Subsidiaries has purchased any of its outstanding capital
stock, nor declared, paid or otherwise made any dividend or
distribution of any kind on its capital stock, and (iii) there
shall not have been any change in the capital stock or long-
term indebtedness of the Company, the Subsidiaries or the IVD
Business which would, individually or in the aggregate, be a
Material Change.

            (q)  Each of the Company and the Subsidiaries has
filed all necessary federal, state and foreign income and
franchise tax returns, except where the failure to so file such
returns would not, individually or in the aggregate, have a
Material Adverse Effect, and has paid all taxes shown as due
thereon; and other than tax deficiencies which the Company or
any Subsidiary is contesting in good faith and for which the
Company or such Subsidiary has provided adequate reserves,
there is no tax deficiency that has been asserted against the
Company or any of the Subsidiaries that would have,
individually or in the aggregate, a Material Adverse Effect.

            (r)  The statistical and market-related data included
in the Final Memorandum are based on or derived from sources

 
                                      -10-

which the Company and the Subsidiaries believe to be reliable
and accurate.

            (s)  None of the Company, the Subsidiaries or any
agent acting on their behalf has taken or will take any action
that might cause this Agreement or the sale of the Notes to
violate Regulation G, T, U or X of the Board of Governors of
the Federal Reserve System, in each case as in effect, or as
the same may hereafter be in effect, on the Closing Date.

            (t)  Each of the Company, the Subsidiaries and, to
the knowledge of the Company, after due inquiry, the IVD
Business has, and upon consummation of the Acquisition the
Company and the Subsidiaries will have, good and marketable
title to all real property and good title to all personal
property described in the Final Memorandum as being owned by it
and good and marketable title to a leasehold estate in the real
and personal property described in the Final Memorandum as
being leased by it free and clear of all liens, charges,
encumbrances or restrictions, except as described in the Final
Memorandum or to the extent the failure to have such title or
the existence of such liens, charges, encumbrances or
restrictions would not, individually or in the aggregate, have
a Material Adverse Effect.  All leases, contracts and
agreements to which the Company, any of the Subsidiaries or
DuPont with respect to the IVD Business is a party or by which
any of them is bound are valid and enforceable against the
Company, such Subsidiaries or the IVD Business, to the
knowledge of the Company are valid and enforceable against the
other party or parties thereto and are in full force and effect
with only such exceptions as would not, individually or in the
aggregate, have a Material Adverse Effect.

            (u)  There are no legal or governmental proceedings
involving or affecting the Company, any Subsidiary or to the
knowledge of the Company after due inquiry, DuPont with respect
to the IVD Business or any of their respective properties or
assets which would be required to be described in a prospectus
pursuant to the Act that are not described in the Final
Memorandum, nor are there any material contracts or other
documents which would be required to be described in a
prospectus pursuant to the Act that are not described in the
Final Memorandum.

            (v)  Except as would not, individually or in the
aggregate, have a Material Adverse Effect, (A) each of the
Company, the Subsidiaries and to the knowledge of the Company
after due inquiry, DuPont with respect to the IVD Business is

 
                                      -11-

in compliance with and not subject to liability under
applicable Environmental Laws, (B) each of the Company, the
Subsidiaries and to the knowledge of the Company after due
inquiry, DuPont with respect to the IVD Business has made all
filings and provided all notices required under any applicable
Environmental Law, and has and is in compliance with all
Permits required under any applicable Environmental Laws and
each of them is in full force and effect, (C) there is no
civil, criminal or administrative action, suit, demand, claim,
hearing, notice of violation, investigation, proceeding, notice
or demand letter or request for information pending or, to the
knowledge of the Company or any of the Subsidiaries, threatened
against the Company, any of the Subsidiaries or to the
knowledge of the Company after due inquiry, DuPont with respect
to the IVD Business under any Environmental Law, (D) no lien,
charge, encumbrance or restriction has been recorded under any
Environmental Law with respect to any assets, facility or
property owned, operated, leased or controlled by the Company,
any of the Subsidiaries or to the knowledge of the Company
after due inquiry, DuPont with respect to the IVD Business,
(E) none of the Company, the Subsidiaries or to the knowledge
of the Company after due inquiry, DuPont with respect to the
IVD Business has received notice that it has been identified as
a potentially responsible party under the Comprehensive
Environmental Response, Compensation and Liability Act of 1980,
as amended ("CERCLA"), or any comparable state law, (F) no
             ------
property or facility of the Company, any of the Subsidiaries or
to the knowledge of the Company after due inquiry the IVD
Business is (i) listed or proposed for listing on the National
Priorities List under CERCLA or is (ii) listed in the
Comprehensive Environmental Response, Compensation, Liability
Information System List promulgated pursuant to CERCLA, or on
any comparable list maintained by any state or local
governmental authority.

            For purposes of this Agreement, "Environmental Laws"
means the common law and all applicable federal, state and
local laws or regulations, codes, orders, decrees, judgments or
injunctions issued, promulgated, approved or entered
thereunder, relating to pollution or protection of public or
employee health and safety or the environment, including,
without limitation, laws relating to (i) emissions, discharges,
releases or threatened releases of hazardous materials, into
the environment (including, without limitation, ambient air,
surface water, ground water, land surface or subsurface
strata), (ii) the manufacture, processing, distribution, use,
generation, treatment, storage, disposal, transport or handling
of 

 
                                      -12-

hazardous materials, and (iii) underground and above ground
storage tanks, and related piping, and emissions, discharges,
releases or threatened releases therefrom.

            (w)  There is no strike, labor dispute, slowdown or
work stoppage with the employees of the Company, any of the
Subsidiaries or the IVD Business which is pending or, to the
knowledge of the Company or any of the Subsidiaries,
threatened.

            (x)  Each of the Company, the Subsidiaries and the
IVD Business carries insurance in such amounts and covering
such risks as is adequate for the conduct of its business and
the value of its properties.

            (y)  None of the Company, the Subsidiaries or, to the
knowledge of the Company, the IVD Business has any liability
for any prohibited transaction or funding deficiency or any
complete or partial withdrawal liability with respect to any
pension, profit sharing or other plan which is subject to the
Employee Retirement Income Security Act of 1974, as amended
("ERISA"), to which the Company, any of the Subsidiaries or, to
  -----
the knowledge of the Company, the IVD Business makes or ever
has made a contribution and in which any employee of the
Company, of any Subsidiary or of the IVD Business is or has
ever been a participant.  With respect to such plans, the
Company, each Subsidiary and, to the knowledge of the Company,
the IVD Business are in compliance in all material respects
with all applicable provisions of ERISA.

            (z)  Each of the Company and the Subsidiaries
(i) makes and keeps accurate books and records and (ii)
maintains internal accounting controls which provide reasonable
assurance that (A) transactions are executed in accordance with
management's authorization, (B) transactions are recorded as
necessary to permit preparation of its financial statements and
to maintain accountability for its assets, (C) access to its
assets is permitted only in accordance with management's
authorization and (D) the reported accountability for its
assets is compared with existing assets at reasonable
intervals.

            (aa)  None of the Company or the Subsidiaries will be
an "investment company" or "promoter" or "principal under
writer" for an "investment company," as such terms are defined
in the Investment Company Act of 1940, as amended, and the
rules and regulations thereunder.

 
                                      -13-

            (bb)  The Notes, the Exchange Notes, the Indenture
and the Registration Rights Agreement will conform in all
material respects to the descriptions thereof in the Final
Memorandum.

            (cc)  No holder of securities of the Company or any
Subsidiary will be entitled to have such securities registered
under the registration statements required to be filed by the
Company pursuant to the Registration Rights Agreement other
than as expressly permitted thereby.

            (dd)  Immediately after the consummation of the
transactions contemplated by this Agreement and the Asset
Purchase Agreement, the fair value and present fair saleable
value of the assets of the Company will exceed the sum of its
stated liabilities and identified contingent liabilities; the
Company is not, nor will the Company be, after giving effect to
the execution, delivery and performance of this Agreement and
the Asset Purchase Agreement, and the consummation of the
transactions contemplated hereby and thereby, (a) left with
unreasonably small capital with which to carry on its business
as it is proposed to be conducted, (b) unable to pay its debts
(contingent or otherwise) as they mature or (c) otherwise
insolvent.

            (ee)  Neither the Company nor its respective
Affiliates (as defined in Rule 501(b) of Regulation D under the
Act) has directly, or through any agent, (i) sold, offered for
sale, solicited offers to buy or otherwise negotiated in
respect of, any "security" (as defined in the Act) which is or
could be integrated with the sale of the Notes in a manner that
would require the registration under the Act of the Notes or
(ii) engaged in any form of general solicitation or general
advertising (as those terms are used in Regulation D under the
Act) in connection with the offering of the Notes or in any
manner involving a public offering within the meaning of
Section 4(2) of the Act.

            (ff)  Assuming the accuracy of the representations
and warranties of the Initial Purchasers in Section 8 hereof,
it is not necessary in connection with the offer, sale and
delivery of the Notes to the Initial Purchasers in the manner
contemplated by this Agreement to register any of the Notes
under the Act or to qualify the Indenture under the TIA.

            (gg)  No securities of the Company are of the same
class (within the meaning of Rule 144A under the Act) as the
Notes and listed on a national securities exchange registered

 
                                      -14-

under Section 6 of the Exchange Act, or quoted in a U.S.
automated inter-dealer quotation system.

            (hh)  None of the Company or the Subsidiaries has
taken, nor will any of them take, directly or indirectly, any
action designed to, or that might be reasonably expected to,
cause or result in stabilization or manipulation of the price
of the Notes.

            Any certificate signed by any officer of the Company
or any Subsidiary and delivered to any Initial Purchaser or to
counsel for the Initial Purchasers shall be deemed a joint and
several representation and warranty by the Company and each of
the Subsidiaries to each Initial Purchaser as to the matters
covered thereby.

            3.    Purchase, Sale and Delivery of the Notes.  On
                  ----------------------------------------
the basis of the representations, warranties, agreements and
covenants herein contained and subject to the terms and
conditions herein set forth, the Company agrees to issue and
sell to the Initial Purchasers, and the Initial Purchasers,
acting severally and not jointly, agree to purchase the Notes
in the respective amounts set forth on Schedule 1 hereto from
                                       ----------
the Company, at 97% of their principal amount.  One or more
certificates in definitive form for the Notes that the Initial
Purchasers have agreed to purchase hereunder, and in such
denomination or denominations and registered in such name or
names as the Initial Purchasers request upon notice to the
Company at least 36 hours prior to the Closing Date, shall be
delivered by or on behalf of the Company to the Initial
Purchasers, against payment by or on behalf of the Initial
Purchasers of the purchase price therefor by wire transfer
(same day funds), net of the overnight cost of such funds, to
such account or accounts as the Company shall specify prior to
the Closing Date, or by such means as the parties hereto shall
agree prior to the Closing Date.  Such delivery of and payment
for the Notes shall be made at the offices of Cahill Gordon &
Reindel, 80 Pine Street, New York, New York at 10:00 A.M., New
York time, on May 7, 1996, or at such other place, time or date
as the Initial Purchasers, on the one hand, and the Company, on
the other hand, may agree upon, such time and date of delivery
against payment being herein referred to as the "Closing Date."
                                                 ------------
The Company will make such certificate or certificates for the
Notes available for checking and packaging by the Initial
Purchasers at the offices of BT Securities Corporation in New
York, New York, or at such other place as BT Securities
Corporation may designate, at least 24 hours prior to the
Closing Date.

 
                                      -15-

            4.    Offering by the Initial Purchasers.  The Initial
                  ----------------------------------
Purchasers propose to make an offering of the Notes at the
price and upon the terms set forth in the Final Memorandum, as
soon as practicable after this Agreement is entered into and as
in the judgment of the Initial Purchasers is advisable.

            5.    Covenants of the Company.  The Company covenants
                  ------------------------
and agrees with each of the Initial Purchasers that:

            (a)  The Company will not amend or supplement the
Final Memorandum or any amendment or supplement thereto of
which the Initial Purchasers shall not previously have been
advised and furnished a copy for a reasonable period of time
prior to the proposed amendment or supplement and as to which
the Initial Purchasers shall not have given their consent.  The
Company will promptly, upon the reasonable request of the
Initial Purchasers or counsel for the Initial Purchasers, make
any amendments or supplements to the Preliminary Memorandum or
the Final Memorandum that may be necessary or advisable in
connection with the resale of the Notes by the Initial
Purchasers.

            (b)  The Company will cooperate with the Initial
Purchasers in arranging for the qualification of the Notes for
offering and sale under the securities or "Blue Sky" laws of
which jurisdictions as the Initial Purchasers may designate and
will continue such qualifications in effect for as long as may
be necessary to complete the resale of the Notes; provided,
                                                  --------
however, that in connection therewith, the Company shall not be
- -------
required to qualify as a foreign corporation or to execute a
general consent to service of process in any jurisdiction or
subject itself to taxation in excess of a nominal dollar amount
in any such jurisdiction where it is not then so subject.

            (c)  If, at any time prior to the completion of the
distribution by the Initial Purchasers of the Notes or the
Private Exchange Notes, any event occurs or information becomes
known as a result of which the Final Memorandum as then amended
or supplemented would include any untrue statement of a
material fact, or omit to state a material fact necessary to
make the statements therein, in the light of the circumstances
under which they were made, not misleading, or if for any other
reason it is necessary at any time to amend or supplement the
Final Memorandum to comply with applicable law, the Company
will promptly notify the Initial Purchasers thereof and will
prepare, at the expense of the Company, an amendment or
supplement to the Final Memorandum that corrects such statement
or omission or effects such compliance.

 
                                      -16-

            (d)  The Company will, without charge, provide to the
Initial Purchasers and to counsel for the Initial Purchasers as
many copies of the Preliminary Memorandum and the Final
Memorandum or any amendment or supplement thereto as the
Initial Purchasers may reasonably request.

            (e)  The Company will apply the net proceeds from the
sale of the Notes as set forth under "Use of Proceeds" in the
Final Memorandum.

            (f)  For so long as any of the Notes remain
outstanding, the Company will furnish to the Initial Purchasers
copies of all reports and other communications (financial or
otherwise) furnished by the Company to the Trustee, or the
holders of the Notes and, as soon as available, copies of any
reports or financial statements furnished to or filed by the
Company with the Commission or any national securities exchange
on which any class of securities of the Company may be listed.

            (g)  Prior to the Closing Date, the Company will
furnish to the Initial Purchasers, as soon as they have been
prepared, a copy of any unaudited interim financial statements
of the Company and the IVD Business for any period subsequent
to the period covered by the most recent financial statements
appearing in the Final Memorandum.

            (h)  None of the Company or any of its Affiliates
will sell, offer for sale or solicit offers to buy or otherwise
negotiate in respect of any "security" (as defined in the Act)
which could be integrated with the sale of the Notes in a
manner which would require the registration under the Act of
the Notes.

            (i)  The Company will not, and will not permit any of
the Subsidiaries to, engage in any form of general solicitation
or general advertising (as those terms are used in Regulation D
under the Act) in connection with the offering of the Notes or
in any manner involving a public offering within the meaning of
Section 4(2) of the Act.

            (j)  For so long as any of the Notes remain
outstanding, the Company will make available, upon request, to
any seller of such Notes the information specified in Rule
144A(d)(4) under the Act, unless the Company is then subject to
Section 13 or 15(d) of the Exchange Act.

 
                                      -17-

            (k)  The Company will use its best efforts to
(i) permit the Notes to be designated PORTAL securities in
accordance with the rules and regulations adopted by the NASD
relating to trading in the Private Offerings, Resales and
Trading through Automated Linkages market (the "Portal Market")
                                                -------------
and (ii) permit the Notes to be eligible for clearance and
settlement through The Depository Trust Company.

            6.    Expenses.  The Company agrees to pay all costs
                  --------
and expenses incident to the performance of its obligations
under this Agreement, whether or not the transactions
contemplated herein are consummated or this Agreement is
terminated pursuant to Section 11 hereof, including all costs
and expenses incident to (i) the printing, word processing or
other production of documents with respect to the transactions
contemplated hereby, including any costs of printing the
Preliminary Memorandum and the Final Memorandum and any
amendment or supplement thereto, and any "Blue Sky" memoranda,
(ii) all arrangements relating to the delivery to the Initial
Purchasers of copies of the foregoing documents, (iii) the fees
and disbursements of the counsel, the accountants and any other
experts or advisors retained by the Company, (iv) preparation
(including printing), issuance and delivery to the Initial
Purchasers of the Notes, (v) the qualification of the Notes
under state securities and "Blue Sky" laws, including filing
fees and fees and disbursements of counsel for the Initial
Purchasers relating thereto, (vi) expenses of the Company in
connection with any meetings with prospective investors in the
Notes, (vii) fees and expenses of the Trustee including fees
and expenses of counsel, (viii) all expenses and listing fees
incurred in connection with the application for quotation of
the Notes on the PORTAL Market and (ix) any fees charged by
investment rating agencies for the rating of the Notes.  If the
sale of the Notes provided for herein is not consummated
because any condition to the obligations of the Initial
Purchasers set forth in Section 7 hereof is not satisfied,
because this Agreement is terminated pursuant to Section 11
hereof or because of any failure, refusal or inability on the
part of the Company to perform all obligations and satisfy all
conditions on its part to be performed or satisfied hereunder
(other than solely by reason of a default by the Initial
Purchasers of their obligations hereunder after all conditions
hereunder have been satisfied in accordance herewith), the
Company agrees to promptly reimburse the Initial Purchasers
upon demand for all out-of-pocket expenses (including fees,
disbursements and charges of Cahill Gordon & Reindel, counsel
for the Initial Purchasers) that 

 
                                      -18-

shall have been incurred by the Initial Purchasers in connection 
with the proposed purchase and sale of the Notes.  

            7.    Conditions of the Initial Purchasers'
                  ------------------------------------
Obligations.  The obligation of the Initial Purchasers to
- -----------
purchase and pay for the Notes shall, in their sole discretion,
be subject to the satisfaction or waiver of the following
conditions on or prior to the Closing Date:

            (a)  All of the conditions contained in the Credit
Agreement to be fulfilled or complied with prior to any
borrowing under such agreement shall have been complied with;
and the financing for the Acquisition (other than the offering
and sale of the Notes as set forth herein and the application
of the proceeds therefrom) shall have been consummated or shall
be consummated simultaneously herewith.

            (b)  On the Closing Date, the Initial Purchasers
shall have received the opinion, dated as of the Closing Date
and addressed to the Initial Purchasers, of Kirkland & Ellis,
counsel for the Company, in form and substance satisfactory to
counsel for the Initial Purchasers, to the effect that:

            (i)  Each of the Company and the Subsidiaries on
      Schedule A attached to such opinion is duly incorporated,
      validly existing and in good standing under the laws of
      its respective jurisdiction of incorporation and has all
      requisite corporate power and authority to own, lease and
      operate its properties and to conduct its business as
      described in the Final Memorandum.  The Company is duly
      qualified as a foreign corporation and in good standing in
      the jurisdictions set forth on Schedule B attached to such
      opinion.

           (ii)  The Company has the capitalization set forth in
      the Final Memorandum; all of the outstanding shares of
      capital stock of the Company have been duly authorized and
      validly issued, are fully paid and nonassessable and were
      not issued in violation of any preemptive or similar
      rights.

          (iii)  Except as set forth in or contemplated by the
      Final Memorandum, (A) no options, warrants or other rights
      to purchase from the Company shares of capital stock or
      ownership interests in the Company are outstanding, (B) no
      agreements or other obligations of the Company to issue,
      or other rights to cause the Company to convert, any

 
                                      -19-

      obligation into, or exchange any securities for, shares of
      capital stock or ownership interests in the Company are
      outstanding and (C) no holder of securities of the Company
      is entitled to have such securities registered under a
      registration statement filed by the Company pursuant to
      the Registration Rights Agreement.

           (iv)  The Company has all requisite corporate power
      and authority to execute, deliver and perform its
      obligations under the Indenture, the Notes, the Exchange
      Notes and the Private Exchange Notes; the Indenture is in
      sufficient form for qualification under the TIA; the
      Indenture has been duly and validly authorized by the
      Company and, when duly executed and delivered by the
      Company (assuming the due authorization, execution and
      delivery thereof by the Trustee), will constitute the
      valid and legally binding agreement of the Company,
      enforceable against the Company in accordance with its
      terms, except that the enforcement thereof may be subject
      to (i) bankruptcy, insolvency, reorganization, moratorium
      or other similar laws now or hereafter in effect relating
      to creditors' rights generally and (ii) general principles
      of equity and the discretion of the court before which any
      proceeding therefor may be brought.

            (v)  The Notes are in the form contemplated by the
      Indenture.  The Notes have each been duly and validly
      authorized by the Company and when duly executed and
      delivered by the Company and paid for by the Initial
      Purchasers in accordance with the terms of this Agreement
      (assuming the due authorization, execution and delivery of
      the Indenture by the Trustee and due authentication and
      delivery of the Notes by the Trustee in accordance with
      the Indenture), will constitute the valid and legally
      binding obligations of the Company, entitled to the
      benefits of the Indenture, and enforceable against the
      Company in accordance with their terms, except that the
      enforcement thereof may be subject to (i) bankruptcy,
      insolvency, reorganization, moratorium or other similar
      laws now or hereafter in effect relating to creditors'
      rights generally and (ii) general principles of equity and
      the discretion of the court before which any proceeding
      therefor may be brought.

           (vi)  The Exchange Notes and the Private Exchange
      Notes have been duly and validly authorized by the Company
      and, when the Exchange Notes and the Private Exchange

 
                                      -20-

      Notes have been duly executed and delivered by the Company
      in accordance with the terms of the Registration Rights
      Agreement and the Indenture (assuming the due
      authorization, execution and delivery of the Indenture by
      the Trustee and due authentication and delivery of the
      Exchange Notes and the Private Exchange Notes by the
      Trustee in accordance with the Indenture), will constitute
      the valid and legally binding obligations of the Company,
      entitled to the benefits of the Indenture, and enforceable
      against the Company in accordance with their terms, except
      that the enforcement thereof may be subject to
      (i) bankruptcy, insolvency, reorganization, moratorium or
      other similar laws now or hereafter in effect relating to
      creditors' rights generally and (ii) general principles of
      equity and the discretion of the court before which any
      proceeding therefor may be brought.

          (vii)  The Company has all requisite corporate power
      and authority to execute, deliver and perform its
      obligations under the Registration Rights Agreement; the
      Registration Rights Agreement has been duly and validly
      authorized by the Company and, when duly executed and
      delivered by the Company (assuming due authorization,
      execution and delivery thereof by the Initial Purchasers),
      will constitute the valid and legally binding agreement of
      the Company enforceable against the Company in accordance
      with its terms, except that (A) the enforcement thereof
      may be subject to (i) bankruptcy, insolvency,
      reorganization, moratorium or other similar laws now or
      hereafter in effect relating to creditors' rights
      generally and (ii) general principles of equity and the
      discretion of the court before which any proceeding
      therefor may be brought and (B) any rights to indemnity or
      contribution thereunder may be limited by federal and
      state securities laws and public policy considerations.

         (viii)  The Company has all requisite corporate power
      and authority to execute, deliver and perform its
      obligations under this Agreement and to consummate the
      transactions contemplated hereby; this Agreement and the
      consummation by the Company of the transactions
      contemplated hereby have been duly and validly authorized
      by the Company.  This Agreement has been duly executed and
      delivered by the Company.

           (ix)  The Indenture, the Notes, the Exchange Notes and
      the Registration Rights Agreement conform as to legal

 
                                      -21-

      matters in all material respects to the descriptions
      thereof contained in the Final Memorandum.

            (x)  To the knowledge of such counsel, no legal or
      governmental proceedings are pending to which the Company
      is, or upon consummation of the Acquisition will be, a
      party or to which the property or assets of the Company is
      subject which would be required under the Act to be
      described in a registration statement or in a prospectus
      and are not described in the Final Memorandum, or which
      seek to restrain, enjoin, prevent the consummation of or
      otherwise challenge the issuance or sale of the Notes to
      be sold hereunder or the consummation of the other
      transactions described in the Final Memorandum under the
      caption "Use of Proceeds" or the "Transactions."

           (xi)  To the knowledge of such counsel, no contract,
      agreement or other document to which the Company or any of
      the Subsidiaries is, or upon consummation of the
      Acquisition will be, a party would be required under the
      Act to be described in a registration statement or
      prospectus that is not described in the Final Memorandum;
      provided, however, that no opinion is expressed with
      respect to the matters summarized, or required to be
      summarized, under "Private Placement" in the Final
      Memorandum.

          (xii)  The Company is not, and upon consummation of the
      Acquisition will not be, (i) in violation of its
      certificate of incorporation or bylaws (or similar
      organizational document), (ii) to the knowledge such
      counsel, in breach or violation of any statute, judgment,
      decree, order, rule or regulation applicable to any of
      them or any of their respective properties or assets,
      except for any such breach or violation which would not,
      individually or in the aggregate, have a Material Adverse
      Effect, or (iii) to the knowledge of such counsel, in
      breach or default under (nor has any event occurred which,
      with notice or passage of time or both, would constitute a
      default under) or in violation of any of the terms or
      provisions of any contract set forth on Schedule 3 to this
      Agreement, except for any such breach, default, violation
      or event which would not, individually or in the
      aggregate, have a Material Adverse Effect.

         (xiii)  The execution and delivery of this Agreement,
      the Indenture, the Registration Rights Agreement, the
      Asset Purchase Agreement and the related documents and the

 
                                      -22-

      consummation of the transactions contemplated hereby and
      thereby (including, without limitation, the issuance and
      sale of the Notes to the Initial Purchasers) will not
      conflict with or constitute or result in a breach or a
      default under (or an event which with notice or passage of
      time or both would constitute a default under) or
      violation of any of (i) the terms or provisions of any
      contract set forth on Schedule 3 to this Agreement, except
      for any such conflict, breach, violation, default or event
      which would not, individually or in the aggregate, have a
      Material Adverse Effect, (ii) the certificate of
      incorporation or bylaws (or similar organizational
      document) of the Company, or (iii) (assuming compliance
      with all applicable state securities or "Blue Sky" laws
      and assuming the accuracy of the representations and
      warranties of the Initial Purchasers in Section 8 hereof)
      any statute, judgment, decree, order, rule or regulation
      which, in our experience, is normally applicable both to
      general business corporations which are not engaged in
      regulated business activities and to transactions of the
      type contemplated by the Final Memorandum (but without our
      having made any special investigation as to other laws and
      provided that such opinion need not cover any laws or
      regulations to which the Company or its affiliates may be
      subject as a result of any of the Initial Purchasers'
      legal or regulatory status or the involvement of any of
      the Initial Purchasers in such transaction), except for
      any such conflict, breach or violation which would not,
      individually or in the aggregate, have a Material Adverse
      Effect.

          (xiv)  To the knowledge of such counsel, no consent,
      approval, authorization or order of any governmental
      authority is required for the performance of the Asset
      Purchase Agreement and the related documents or the
      issuance and sale by the Company of the Notes to the
      Initial Purchasers or the other transactions contemplated
      hereby, except such as may be required under Blue Sky
      laws, as to which such counsel need express no opinion,
      and those which have previously been obtained.

           (xv)  None of the Company or the Subsidiaries is, or
      immediately after the sale of the Notes to be sold
      hereunder and the application of the proceeds from such
      sale (as described in the Final Memorandum under the
      caption "Use of Proceeds") will be, an "investment
      company" as such term is defined in the Investment Company
      Act of 1940, as amended.

 
                                      -23-

          (xvi)  No registration under the Act of the Notes is
      required in connection with the sale of the Notes to the
      Initial Purchasers as contemplated by this Agreement and
      the Final Memorandum or in connection with the initial
      resale of the Notes by the Initial Purchasers in
      accordance with Section 8 of this Agreement, and prior to
      the commencement of the Exchange Offer (as defined in the
      Registration Rights Agreement) or the effectiveness of the
      Shelf Registration Statement (as defined in the
      Registration Rights Agreement), the Indenture is not
      required to be qualified under the TIA, in each case
      assuming (i) that the purchasers who buy such Notes in the
      initial resale thereof are qualified institutional buyers
      as defined in Rule 144A promulgated under the Act ("QIBs")
      or accredited investors as defined in Rule 501(a) (1),
      (2), (3) or (7) promulgated under the Act ("Accredited
      Investors"), (ii) the accuracy of the Initial Purchasers'
      representations in Section 8 and those of the Company
      contained in this Agreement regarding the absence of a
      general solicitation in connection with the sale of such
      Notes to the Initial Purchasers and the initial resale
      thereof, (iii) the due performance by the Initial
      Purchasers of the agreements set forth in Section 8 hereof
      and (iv) the accuracy of the representations made by each
      Accredited Investor who purchases Notes in the initial
      resale as set forth in the Final Memorandum.

         (xvii)  Neither the consummation of the transactions
      contemplated by this Agreement nor the sale, issuance,
      execution or delivery of the Notes will violate
      Regulation G, T, U or X of the Board of Governors of the
      Federal Reserve System.

        (xviii)  The Company has all requisite corporate power
      and corporate authority to execute, deliver and perform
      its obligations under the Asset Purchase Agreement; the
      Asset Purchase Agreement has been duly authorized by
      requisite corporate action on the part of the Company and
      constitutes the legal, valid and binding agreement of the
      Company, enforceable against the Company in accordance
      with its terms, except that the enforcement thereof may be
      subject to (i) bankruptcy, insolvency, reorganization,
      moratorium or other similar laws now or hereafter in
      effect relating to creditors' rights generally and
      (ii) general principles of equity and the discretion of
      the court before which any proceeding therefor may be
      brought.

 
                                      -24-

          (xix)  The Credit Agreement has been duly authorized,
      executed and delivered by the Company and Holdings.

            At the time the foregoing opinion is delivered,
Kirkland & Ellis shall additionally state that it has
participated in conferences with officers and other
representatives of the Company, representatives of the
independent public accountants for the Company, representatives
of the Initial Purchasers and counsel for the Initial
Purchasers, at which conferences the contents of the Final
Memorandum and related matters were discussed, and, although it
has not independently verified and is not passing upon and
assumes no responsibility for the accuracy, completeness or
fairness of the statements contained in the Final Memorandum
(except to the extent specified in subsection 7(b)(ix)), no
facts have come to its attention which lead it to believe that
the Final Memorandum, on the date thereof or at the Closing
Date, contained an untrue statement of a material fact or
omitted to state a material fact required to be stated therein
or necessary to make the statements contained therein, in the
light of the circumstances under which they were made, not
misleading (it being understood that such firm need express no
opinion with respect to the financial statements and related
notes thereto and the other financial, statistical and
accounting data included in the Final Memorandum).  The opinion
of Kirkland & Ellis described in this Section shall be rendered
to the Initial Purchasers at the request of the Company and
shall so state therein.

            References to the Final Memorandum in this
subsection (b) shall include any amendment or supplement
thereto prepared in accordance with the provisions of this
Agreement at the Closing Date.

            In rendering such opinion, such counsel may state
that they express no opinion as to the laws of any jurisdiction
other than the federal laws of the United States, the laws of
the State of New York and the Delaware General Corporation Law.
Such counsel may also state that, insofar as such opinion
involves factual matters, such counsel have relied, to the
extent they deem proper, upon certificates of officers of the
Company and certificates of public officials; provided that
                                              --------
such certificates have been provided to the Initial Purchasers;
provided, further, that for the purposes of such opinion
- --------  -------
"Material Adverse Effect" need not be defined to include the
prospects of the Company and its Subsidiaries.

 
                                      -25-

            (c)  On the Closing Date, the Initial Purchasers
shall have received the opinion, in form and substance
satisfactory to counsel for the Initial Purchasers, dated as of
the Closing Date and addressed to the Initial Purchasers, of
counsel for DuPont.

            (d)  On the Closing Date, the Initial Purchaser shall
have received the opinion, in form and substance satisfactory
to the Initial Purchasers, dated as of the Closing Date and
addressed to the Initial Purchasers, of Cahill Gordon &
Reindel, counsel for the Initial Purchasers, with respect to
certain legal matters relating to this Agreement and such other
related matters as the Initial Purchasers may reasonably
require.  In rendering such opinion, Cahill Gordon & Reindel
shall have received and may rely upon such certificates and
other documents and information as it may reasonably request to
pass upon such matters.

            (e)  The Initial Purchasers shall have received from
the Independent Accountants comfort letters dated the date
hereof and the Closing Date, in form and substance satisfactory
to counsel for the Initial Purchasers.

            (f)  The representations and warranties of the
Company contained in this Agreement shall be true and correct
on and as of the date hereof and on and as of the Closing Date
as if made on and as of the Closing Date; the statements of the
Company's officers made pursuant to any certificate delivered
in accordance with the provisions hereof shall be true and
correct on and as of the date made and on and as of the Closing
Date; the Company shall have performed all covenants and
agreements and satisfied all conditions on its part to be
performed or satisfied hereunder at or prior to the Closing
Date; and, except as described in the Final Memorandum
(exclusive of any amendment or supplement thereto after the
date hereof), subsequent to the date of the most recent
financial statements in such Final Memorandum, there shall have
been no event or development that, individually or in the
aggregate, has or would be reasonably likely to have a Material
Adverse Effect.

            (g)  The Acquisition and the sale of the Notes
hereunder shall not be enjoined (temporarily or permanently) on
the Closing Date.

            (h)  Subsequent to the date of the most recent
financial statements in the Final Memorandum (exclusive of any
amendment or supplement thereto after the date hereof), the

 
                                      -26-

conduct of the business and operations of the Company, any of
the Subsidiaries or the IVD Business shall not have been
interfered with by strike, fire, flood, hurricane, accident or
other calamity (whether or not insured) or by any court or
governmental action, order or decree, and, except as otherwise
stated therein, the properties of the Company, any of the
Subsidiaries or the IVD Business shall not have sustained any
loss or damage (whether or not insured) as a result of any such
occurrence, except any such interference, loss or damage which
would not, individually or in the aggregate, have a Material
Adverse Effect. 

            (i)  The Initial Purchasers shall have received a
certificate of the Company, dated the Closing Date, signed by
its Chairman of the Board, President or any Senior Vice
President and the Chief Financial Officer, to the effect that:

            (i)  The representations and warranties of the
      Company contained in this Agreement are true and correct
      as of the date hereof and as of the Closing Date, and the
      Company has performed all covenants and agreements and
      satisfied all conditions on its part to be performed or
      satisfied hereunder at or prior to the Closing Date;

           (ii)  At the Closing Date, since the date hereof or
      since the date of the most recent financial statements in
      the Final Memorandum (exclusive of any amendment or
      supplement thereto after the date hereof), no event or
      events have occurred, no information has become known nor
      does any condition exist that, individually or in the
      aggregate, would have a Material Adverse Effect;

          (iii)  The Acquisition and the sale of the Notes
      hereunder have not been enjoined (temporarily or
      permanently); and

           (iv)  There have been no material amendments,
      alterations, modifications or waivers of any provisions of
      the Asset Purchase Agreement and related documents since
      the date of the execution and delivery thereof by the
      parties thereto; the Company, to the best knowledge of
      such officer after due inquiry, DuPont and its affiliates,
      to the extent each is a party thereto, have complied in
      all material respects with all agreements and covenants in
      the Asset Purchase Agreement and related documents and
      performed all conditions specified therein required to be

 
                                      -27-

      complied with or performed by them at or prior to the
      Closing Date.

            (j)  On the Closing Date, the Initial Purchasers
shall have received the Registration Rights Agreement executed
by the Company and such agreement shall be in full force and
effect at all times from and after the Closing Date.

            (k)  The Tender Offer and the Consent Solicitation
shall have been completed and the Company shall have received
tenders and consents representing at least a majority in
aggregate principal amount of the Old Notes outstanding to the
amendments to the Old Notes Indenture set forth in the Offer to
Purchase and Consent Solicitation Statement dated April 7, 1996
as supplemented by the First Supplement thereto dated April 26,
1996.

            (l)  The Supplemental Indenture shall have been duly
executed by the Company and the Old Notes Trustee.

            (m)  The Initial Purchasers shall have received from
the Company a true and correct executed copy of the Credit
Agreement, dated on or about the Closing Date, and there shall
have been no material amendments, alterations, modifications or
waivers of any provisions of the Credit Agreement, and there
exists as of the date hereof and on and as of the Closing Date
(after giving effect to the transactions contemplated by this
Agreement and the application of the proceeds received by the
Company from the sale of the Notes) no condition that would
constitute a Default or an Event of Default (each as defined in
the Credit Agreement) under the Credit Agreement.

            (n)  The Initial Purchasers shall have received from
the Company a true and correct executed copy of the Asset
Purchase Agreement, and there shall have been no material
amendments, alterations, modifications or waivers of any
provisions of the Asset Purchase Agreement since the date of
this Agreement; all conditions to effect the Acquisition set
forth in the Asset Purchase Agreement shall have been satisfied
without waiver.

            (o)  On the Closing Date, the Initial Purchasers
shall have received an opinion from Murray Devine & Co., in a
form reasonably satisfactory to the Initial Purchasers,
regarding the solvency of the Company immediately after the
consummation of the Acquisition and the transactions
contemplated thereby.

 
                                      -28-

            On or before the Closing Date, the Initial Purchasers
and counsel for the Initial Purchasers shall have received such
further documents, opinions, certificates, letters and
schedules or instruments relating to the business, corporate,
legal and financial affairs of the Company and the Subsidiaries
as they shall have heretofore reasonably requested from the
Company.

            All such documents, opinions, certificates, letters,
schedules or instruments delivered pursuant to this Agreement
will comply with the provisions hereof only if they are
reasonably satisfactory in all material respects to the Initial
Purchasers and counsel for the Initial Purchasers.  The Company
shall furnish to the Initial Purchasers such conformed copies
of such documents, opinions, certificates, letters, schedules
and instruments in such quantities as the Initial Purchasers
shall reasonably request.

            8.    Offering of Notes; Restrictions on Transfer.
                  -------------------------------------------
Each of the Initial Purchasers represents and warrants (as to
itself only) that it is a QIB.  Each of the Initial Purchasers
agrees with the Company (as to itself only) that (i) it has not
and will not solicit offers for, or offer or sell, the Notes by
any form of general solicitation or general advertising (as
those terms are used in Regulation D under the Act) or in any
manner involving a public offering within the meaning of
Section 4(2) of the Act; and (ii) it has and will solicit
offers for the Notes only from, and will offer the Notes only
to (A) in the case of offers inside the United States,
(x) persons whom the Initial Purchasers reasonably believe to
be QIBs or, if any such person is buying for one or more
institutional accounts for which such person is acting as
fiduciary or agent, only when such person has represented to
the Initial Purchasers that each such account is a QIB, to whom
notice has been given that such sale or delivery is being made
in reliance on Rule 144A, and, in each case, in transactions
under Rule 144A or (y) a limited number of other institutional
investors reasonably believed by the Initial Purchasers to be
Accredited Investors that, prior to their purchase of the
Notes, deliver to the Initial Purchasers a letter containing
the representations and agreements set forth in Annex A to the
Final Memorandum and (B) in the case of offers outside the
United States, to persons other than U.S. persons ("foreign
purchasers," which term shall include dealers or other
professional fiduciaries in the United States acting on a
discretionary basis for foreign beneficial owners (other than
an estate or trust)); provided, however, that in the case of
                      --------  -------
this clause (B), in purchasing 

 
                                      -29-

such Notes such persons are deemed to have represented and 
agreed as provided under the caption "Transfer Restrictions" 
contained in the Final Memorandum.

            9.    Indemnification and Contribution.  (a)  The
                  --------------------------------
Company agrees to indemnify and hold harmless the Initial
Purchasers and the affiliates, directors, officers, agents,
representatives and employees of the Initial Purchasers or
their affiliates, and each other person, if any, who controls
any Initial Purchaser or its affiliates within the meaning of
Section 15 of the Act or Section 20 of the Exchange Act,
against any losses, claims, damages or liabilities to which any
Initial Purchaser or such other person may become subject under
the Act, the Exchange Act or otherwise, insofar as any such
losses, claims, damages or liabilities (or actions in respect
thereof) arise out of or are based upon:

            (i)  any untrue statement or alleged untrue statement
      of any material fact contained in any Memorandum or any
      amendment or supplement thereto or any application or
      other document, or any amendment or supplement thereto,
      executed by the Company or based upon written information
      furnished by or on behalf of the Company filed in any
      jurisdiction in order to qualify the Notes under the
      securities or "Blue Sky" laws thereof or filed with any
      securities association or securities exchange (each an
      "Application"); or

           (ii)  the omission or alleged omission to state, in
      any Memorandum or any amendment or supplement thereto or
      any Application, a material fact required to be stated
      therein or necessary to make the statements therein not
      misleading,

and will reimburse, as incurred, the Initial Purchasers and
each such other person for any legal or other expenses incurred
by the Initial Purchasers or such other person in connection
with investigating, defending against or appearing as a
third-party witness in connection with any such loss, claim,
damage, liability or action; provided, however, the Company
                             --------  -------
will not be liable in any such case to the extent that any such
loss, claim, damage, or liability arises out of or is based
upon any untrue statement or alleged untrue statement or
omission or alleged omission made in any Memorandum or any
amendment or supplement thereto or any Application in reliance
upon and in conformity with written information concerning the
Initial Purchasers furnished to the Company by BT Securities

 
                                      -30-

Corporation, on behalf of the Initial Purchasers, specifically
for use therein.  This indemnity agreement will be in addition
to any liability that the Company may otherwise have to the
indemnified parties; and provided, further, that the Company
                         --------  -------
will not be liable to any of the Initial Purchasers or any
other person controlling any of the Initial Purchasers or any
of their respective affiliates, directors, officers, agents,
representatives or employees with respect to any such untrue
statement or omission made in the Preliminary Memorandum that
is corrected in the Final Memorandum (or any amendment or
supplement thereto) if the person asserting any such loss,
claim, damage or liability purchased Notes from any of the
Initial Purchasers in reliance upon the Preliminary Memorandum
but was not sent or given a copy of the Final Memorandum (as
amended or supplemented) at or prior to the written
confirmation of the sale of such Notes to such person, unless
such failure to deliver the Final Memorandum (as amended or
supplemented) was a result of noncompliance by the Company with
Section 5(d) of this Agreement.  The Company shall not be
liable under this Section 9 for any settlement of any claim or
action effected without its prior written consent, which shall
not be unreasonably withheld.

            (b)  Each of the Initial Purchasers severally agrees
to indemnify and hold harmless the Company, its directors, its
officers and each person, if any, who controls the Company
within the meaning of Section 15 of the Act or Section 20 of
the Exchange Act against any losses, claims, damages or
liabilities to which the Company or any such director, officer
or controlling person may become subject under the Act, the
Exchange Act or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise
out of or are based upon (i) any untrue statement or alleged
untrue statement of any material fact contained in any
Memorandum or any amendment or supplement thereto or any
Application or (ii) the omission or the alleged omission to
state therein a material fact required to be stated in any
Memorandum or any amendment or supplement thereto or any
Application, or necessary to make the statements therein not
misleading, in each case to the extent, but only to the extent,
that such untrue statement or alleged untrue statement or
omission or alleged omission was made in reliance upon and in
conformity with written information concerning such Initial
Purchaser, furnished to the Company by the Initial Purchasers
specifically for use therein; and subject to the limitation set
forth immediately preceding this clause, will reimburse, as
incurred, any legal or other expenses incurred by the Company
or any such director, 

 
                                      -31-

officer or controlling person in connection with investigating 
or defending against or appearing as a third party witness in 
connection with any such loss, claim, damage, liability or 
action in respect thereof.  This indemnity agreement will be 
in addition to any liability that the Initial Purchasers may 
otherwise have to the indemnified parties.  The Initial 
Purchasers shall not be liable under this Section 9 for any 
settlement of any claim or action effected without their consent, 
which shall not be unreasonably withheld.  The Company shall not, 
without the prior written consent of the Initial Purchasers, 
effect any settlement or compromise of any pending or threatened 
proceeding in respect of which any Initial Purchaser is or could 
have been a party, or indemnity could have been sought hereunder 
by any Initial Purchaser, unless such settlement (A) includes an 
unconditional written release of the Initial Purchasers, in form 
and substance reasonably satisfactory to the Initial Purchasers,
from all liability on claims that are the subject matter of
such proceeding and (B) does not include any statement as to an
admission of fault, culpability or failure to act by or on
behalf of any Initial Purchaser.

            (c)  Promptly after receipt by an indemnified party
under this Section 9 of notice of the commencement of any
action for which such indemnified party is entitled to
indemnification under this Section 9, such indemnified party
will, if a claim in respect thereof is to be made against the
indemnifying party under this Section 9, notify the
indemnifying party of the commencement thereof in writing; but
the omission to so notify the indemnifying party (i) will not
relieve it from any liability under paragraph (a) or (b) above
unless and to the extent such failure results in the forfeiture
by the indemnifying party of substantial rights and defenses
and (ii) will not, in any event, relieve the indemnifying party
from any obligations to any indemnified party other than the
indemnification obligation provided in paragraphs (a) and (b)
above.  In case any such action is brought against any
indemnified party, and it notifies the indemnifying party of
the commencement thereof, the indemnifying party will be
entitled to participate therein and, to the extent that it may
wish, jointly with any other indemnifying party similarly
notified, to assume the defense thereof, with counsel
reasonably satisfactory to such indemnified party; provided,
                                                   --------
however, that if (i) the use of counsel chosen by the
- -------
indemnifying party to represent the indemnified party would
present such counsel with a conflict of interest, (ii) the
defendants in any such action include both the indemnified
party and the indemnifying party and the indemnified party
shall have been advised by counsel that there may be one 

 
                                      -32-

or more legal defenses available to it and/or other indemnified
parties that are different from or additional to those
available to the indemnifying party, or (iii) the indemnifying
party shall not have employed counsel reasonably satisfactory
to the indemnified party to represent the indemnified party
within a reasonable time after receipt by the indemnifying
party of notice of the institution of such action, then, in
each such case, the indemnifying party shall not have the right
to direct the defense of such action on behalf of such
indemnified party or parties and such indemnified party or
parties shall have the right to select separate counsel to
defend such action on behalf of such indemnified party or
parties.  After notice from the indemnifying party to such
indemnified party of its election so to assume the defense
thereof and approval by such indemnified party of counsel
appointed to defend such action, the indemnifying party will
not be liable to such indemnified party under this Section 9
for any legal or other expenses, other than reasonable costs of
investigation, subsequently incurred by such indemnified party
in connection with the defense thereof, unless (i) the
indemnified party shall have employed separate counsel in
accordance with the proviso to the immediately preceding
sentence (it being understood, however, that in connection with
such action the indemnifying party shall not be liable for the
expenses of more than one separate counsel (in addition to
local counsel) in any one action or separate but substantially
similar actions in the same jurisdiction arising out of the
same general allegations or circumstances, designated by the
Initial Purchasers in the case of paragraph (a) of this Section
9 or the Company in the case of paragraph (b) of this
Section 9, representing the indemnified parties under such
paragraph (a) or paragraph (b), as the case may be, who are
parties to such action or actions) or (ii) the indemnifying
party has authorized in writing the employment of counsel for
the indemnified party at the expense of the indemnifying party.
After such notice from the indemnifying party to such
indemnified party, the indemnifying party will not be liable
for the costs and expenses of any settlement of such action
effected by such indemnified party without the prior written
consent of the indemnifying party (which consent shall not be
unreasonably withheld), unless such indemnified party waived in
writing its rights under this Section 9, in which case the
indemnified party may effect such a settlement without such
consent.

            (d)  In circumstances in which the indemnity
agreement provided for in the preceding paragraphs of this
Section 9 is unavailable to, or insufficient to hold harmless,
an 

 
                                      -33-

indemnified party in respect of any losses, claims, damages
or liabilities (or actions in respect thereof), each
indemnifying party, in order to provide for just and equitable
contribution, shall contribute to the amount paid or payable by
such indemnified party as a result of such losses, claims,
damages or liabilities (or actions in respect thereof) in such
proportion as is appropriate to reflect (i) the relative
benefits received by the indemnifying party or parties on the
one hand and the indemnified party on the other from the
offering of the Notes or (ii) if the allocation provided by the
foregoing clause (i) is not permitted by applicable law, not
only such relative benefits but also the relative fault of the
indemnifying party or parties on the one hand and the
indemnified party on the other in connection with the
statements or omissions or alleged statements or omissions that
resulted in such losses, claims, damages or liabilities (or
actions in respect thereof).  The relative benefits received by
the Company on the one hand and any Initial Purchaser on the
other shall be deemed to be in the same proportion as the total
proceeds from the offering (before deducting expenses) received
by the Company bear to the total discounts and commissions
received by such Initial Purchaser.  The relative fault of the
parties shall be determined by reference to, among other
things, whether the untrue or alleged untrue statement of a
material fact or the omission or alleged omission to state a
material fact relates to information supplied by the Company on
the one hand, or such Initial Purchaser on the other, the
parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such statement or omission or
alleged statement or omission, and any other equitable
considerations appropriate in the circumstances.  The Company
and the Initial Purchasers agree that it would not be equitable
if the amount of such contribution were determined by pro rata
or per capita allocation or by any other method of allocation
that does not take into account the equitable considerations
referred to in the first sentence of this paragraph (d).
Notwithstanding any other provision of this paragraph (d), no
Initial Purchaser shall be obligated to make contributions
hereunder that in the aggregate exceed the total discounts,
commissions and other compensation received by such Initial
Purchaser under this Agreement, less the aggregate amount of
any damages that such Initial Purchaser has otherwise been
required to pay by reason of the untrue or alleged untrue
statements or the omissions or alleged omissions to state a
material fact, and no person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the
Act) shall be entitled to contribution from any person who was
not guilty of such fraudulent misrepresentation.  For purposes
of this 

 
                                      -34-

paragraph (d), each person, if any, who controls an Initial 
Purchaser within the meaning of Section 15 of the Act or 
Section 20 of the Exchange Act shall have the same rights to
contribution as the Initial Purchasers, and each director of
the Company, each officer of the Company and each person, if
any, who controls the Company within the meaning of Section 15
of the Act or Section 20 of the Exchange Act, shall have the
same rights to contribution as the Company.

            10.   Survival Clause.  The respective
                  ---------------
representations, warranties, agreements, covenants, indemnities
and other statements of the Company, its officers and the
Initial Purchasers set forth in this Agreement or made by or on
behalf of them pursuant to this Agreement shall remain in full
force and effect, regardless of (i) any investigation made by
or on behalf of the Company, any of its officers or directors,
the Initial Purchasers or any other person referred to in
Section 9 hereof and (ii) delivery of and payment for the
Notes.  The respective agreements, covenants, indemnities and
other statements set forth in Sections 6, 9 and 15 hereof shall
remain in full force and effect, regardless of any termination
or cancellation of this Agreement.

            11.   Termination.  (a)  This Agreement may be
                  -----------
terminated in the sole discretion of the Initial Purchasers by
notice to the Company given prior to the Closing Date in the
event that the Company shall have failed, refused or been
unable to perform all obligations and satisfy all conditions on
its part to be performed or satisfied hereunder at or prior
thereto or, if at or prior to the Closing Date:

            (i)  any of the Company, the Subsidiaries or the IVD
      Business shall have sustained any loss or interference
      with respect to its businesses or properties from fire,
      flood, hurricane, accident or other calamity, whether or
      not covered by insurance, or from any strike, labor
      dispute, slow down or work stoppage or any legal or
      governmental proceeding, which loss or interference, in
      the sole judgment of the Initial Purchasers, has had or
      has a Material Adverse Effect, or there shall have been,
      in the sole judgment of the Initial Purchasers, any event
      or development that, individually or in the aggregate, has
      or could be reasonably likely to have a Material Adverse
      Effect (including without limitation a change in control
      of the Company), except in each case as described in the
      Final Memorandum (exclusive of any amendment or supplement
      thereto);

 
                                      -35-

           (ii)  trading in securities of the Company or in
      securities generally on the New York Stock Exchange,
      American Stock Exchange or the Nasdaq National Market
      shall have been suspended or minimum or maximum prices
      shall have been established on any such exchange or
      market;

          (iii)  a banking moratorium shall have been declared by
      New York or United States authorities;

           (iv)  there shall have been (A) an outbreak or
      escalation of hostilities between the United States and
      any foreign power, or (B) an outbreak or escalation of any
      other insurrection or armed conflict involving the United
      States or any other national or international calamity or
      emergency, or (C) any material change in the financial
      markets of the United States which, in the case of (A),
      (B) or (C) above and in the sole judgment of the Initial
      Purchasers, makes it impracticable or inadvisable to
      proceed with the public offering or the delivery of the
      Notes as contemplated by the Final Memorandum; or

            (v)  any securities of the Company (other than the
      Old Notes) shall have been downgraded or placed on any
      "watch list" for possible downgrading by any nationally
      recognized statistical rating organization.

            (b)  Termination of this Agreement pursuant to this
Section 11 shall be without liability of any party to any other
party except as provided in Section 10 hereof.

            12.   Information Supplied by the Initial Purchasers.
                  ----------------------------------------------
The statements set forth in the last paragraph on the front
cover page and in the last two paragraphs and the last two
sentences of the third paragraph under the heading "Private
Placement" in the Final Memorandum (to the extent such
statements relate to the Initial Purchasers) constitute the
only information furnished by the Initial Purchasers to the
Company for the purposes of Sections 2(a) and 9 hereof.

            13.   Notices.  All communications hereunder shall be
                  -------
in writing and, if sent to the Initial Purchasers, shall be
mailed or delivered to BT Securities Corporation, 130 Liberty
Street, New York, New York 10006, Attention:  Corporate Finance
Department; if sent to the Company, shall be mailed or
delivered to the Company at 1717 Deerfield Road, Deerfield, IL
60015-0778, Attention:  Chief Financial Officer; with a copy to

 
                                      -36-

Kirkland & Ellis, 153 East 53rd Street, New York, NY
10022-4675, Attention:  Lance Balk, Esq.

            All such notices and communications shall be deemed
to have been duly given:  when delivered by hand, if personally
delivered; five business days after being deposited in the
mail, postage prepaid, if mailed; and one business day after
being timely delivered to a next-day air courier.

            14.   Successors.  This Agreement shall inure to the
                  ----------
benefit of and be binding upon the Initial Purchasers, the
Company and their respective successors and legal
representatives, and nothing expressed or mentioned in this
Agreement is intended or shall be construed to give any other
person any legal or equitable right, remedy or claim under or
in respect of this Agreement, or any provisions herein
contained; this Agreement and all conditions and provisions
hereof being intended to be and being for the sole and
exclusive benefit of such persons and for the benefit of no
other person except that (i) the indemnities of the Company
contained in Section 9 of this Agreement shall also be for the
benefit of any person or persons who control the Initial
Purchasers within the meaning of Section 15 of the Act or
Section 20 of the Exchange Act and (ii) the indemnities of the
Initial Purchasers contained in Section 9 of this Agreement
shall also be for the benefit of the directors and officers of
the Company and any person or persons who control the Company
within the meaning of Section 15 of the Act or Section 20 of
the Exchange Act.  No purchaser of Notes from the Initial
Purchasers will be deemed a successor because of such purchase.

            15.   APPLICABLE LAW.  THE VALIDITY AND INTERPRETATION
                  --------------
OF THIS AGREEMENT, AND THE TERMS AND CONDITIONS SET FORTH
HEREIN SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH
THE LAWS OF THE STATE OF NEW YORK APPLICABLE TO CONTRACTS MADE
AND TO BE PERFORMED WHOLLY THEREIN, WITHOUT GIVING EFFECT TO
ANY PROVISIONS THEREOF RELATING TO CONFLICTS OF LAW.

            16.   Counterparts.  This Agreement may be executed in
                  ------------
two or more counterparts, each of which shall be deemed an
original, but all of which together shall constitute one and
the same instrument.

 
            If the foregoing correctly sets forth our
understanding, please indicate your acceptance thereof in the
space provided below for that purpose, whereupon this letter
shall constitute a binding agreement between the Company and
the Initial Purchasers.

                                          Very truly yours,

                                          DADE INTERNATIONAL INC.



                                          By: /s/ Kinzie L. Weimer
                                             --------------------------
                                             Name:  KINZIE L. WEIMER
                                             Title: SENIOR VICE PRESIDENT ANDD
                                                    CHIEF FINANCIAL OFFICER

The foregoing Agreement is
hereby confirmed and accepted
as of the date first above
written.

BT SECURITIES CORPORATION



By: /s/ David F. Jacobs
   __________________________
   Name:  
   Title:


CS FIRST BOSTON CORPORATION



By: /s/ Mark R. Patterson
   __________________________
   Name:  Mark R. Patterson
   Title: Managing Director


MORGAN STANLEY & CO. INCORPORATED



By: /s/ Nicholas Osborne
   __________________________
   Name:  Nicholas Osborne
   Title: Vice President