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                                                                   EXHIBIT 10.37

                          ACCUMED INTERNATIONAL, INC.

                                AGENCY AGREEMENT



Commonwealth Associates
733 Third Avenue
New York, New York  10017

                                                                   March 3, 1997

Gentlemen:

         AccuMed International, Inc., a Delaware corporation (the "Company"),
proposes to offer for sale to "accredited investors", in a private placement
(the "Offering"), up to eighty-five (85) units ("Units"), each Unit consisting
of $100,000 principal amount of 12% convertible promissory notes ("Notes") and
10,000 common stock purchase warrants ("Warrants").  A minimum of seventy (70)
Units ("Minimum Offering") and a maximum of eight-five (85) Units ("Maximum
Offering") will be sold in the offering at $100,000 per Unit.  The Units will
be offered pursuant to those terms and conditions acceptable to you as
reflected in the Confidential Term Sheet, including all exhibits, attachments
and supplements thereto (the "Term Sheet").  Of the Units, seventy (70) will be
offered on a "best efforts - all-or-none" basis and fifteen (15) Units will be
offered on a "best efforts" basis.  The Units are being offered pursuant to the
Term Sheet and related documents in accordance with Section 4(2) of the
Securities Act of 1933, as amended (the "Securities Act") and Regulation D
promulgated thereunder.

         Commonwealth Associates is sometimes referred to herein as the
"Placement Agent."  The Term Sheet (including the exhibits thereto), as it may
be amended from time to time, and the form of proposed subscription agreement
between the Company and each subscriber (the "Subscription Agreement") and the
exhibits which are part of the Term Sheet and/or Subscription Agreement are
collectively referred to herein as the "Offering Documents."

         The Company will prepare and deliver to the Placement Agent a
reasonable number of copies of the Offering Documents in form and substance
satisfactory to counsel to the Placement Agent.

         Each prospective investor subscribing to purchase Units ("Subscriber")
will be required to deliver, among other things, a Subscription Agreement and a
confidential purchaser questionnaire ("Questionnaire") in the form to be
provided to offerees.





                                      
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Capitalized terms used herein, unless otherwise defined or unless the context
otherwise indicates, shall have the same meanings provided in the Offering
Documents.

         1.      Appointment of Placement Agent.

                 (a)      You are hereby appointed exclusive Placement Agent of
the Company (subject to your right to have Selected Dealers, as defined in
Section 1(c) hereof, participate in the Offering) during the Offering Period
herein specified for the purposes of assisting the Company in finding qualified
Subscribers pursuant to the offering (the "Offering") described in the Offering
Documents.  The Offering Period shall commence on the day the Offering
Documents are first made available to you by the Company for delivery in
connection with the offering for sale of the Units and shall continue until the
earlier to occur of (i) the sale of all of the Maximum Offering or (ii) March
14, 1997 (unless extended for a period of up to sixty (60) days under
circumstances specified in the Term Sheet).  If the Minimum Offering is not
sold prior to the end of the Offering Period, the Offering will be terminated
and all funds received from Subscribers will be returned, without interest and
without any deduction.  The day that the Offering Period terminates is
hereinafter referred to as the "Termination Date."

                 (b)      Subject to the performance by the Company of all of
its obligations to be performed under this Agreement and to the completeness
and accuracy of all representations and warranties of the Company contained in
this Agreement, Commonwealth Associates hereby accepts such agency and agrees
to use its best efforts to assist the Company in finding qualified subscribers
pursuant to the Offering described in the Offering Documents.  It is understood
that the Placement Agent has no commitment to sell the Units.  Your agency
hereunder is not terminable by the Company except upon termination of the
Offering Period.

                 (c)      You may engage other persons, selected by you in your
discretion, that are members of the National Association of Securities Dealers,
Inc., ("NASD") and that have executed a Selected Dealers Agreement
substantially in the form attached hereto as Schedule A, to assist you in the
Offering (each such person being hereinafter referred to as a "Selected
Dealer") and you may allow such persons such part of the compensation and
payment of expenses payable to you hereunder as you shall determine.  Each
Selected Dealer shall be required to agree in writing to comply with the
provisions of, and to make the representations, warranties and covenants
contained in this Section 1.

                 (d)      Subscriptions for Units shall be evidenced by the
execution by Subscribers of a Subscription Agreement.  No Subscription
Agreement shall be effective unless and until it is accepted by the Company.
Until the Closing, all subscription funds received shall be held as described
in the Subscription Agreement.  The Placement Agent shall not have any
obligation to independently verify the accuracy or completeness of any





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information contained in any Subscription Agreement or the authenticity,
sufficiency, or validity of any check delivered by any prospective investor in
payment for Units.

         2.      Representations and Warranties of the Company.  The Company
represents and warrants to the Placement Agent, as follows:

                 (a)      Securities Law Compliance.  The Offering Documents
conform in all respects with the requirements of Section 4(2) of the Securities
Act and Regulation D promulgated thereunder and with the requirements of all
other published rules and regulations of the Securities and Exchange Commission
(the "Commission") currently in effect relating to "private offerings" to
"accredited investors" of the type contemplated by the Company.  The Offering
Documents will not contain an untrue statement of a material fact or omit to
state any material fact necessary in order to make the statements therein, in
light of the circumstances in which they were made, not misleading.  If at any
time prior to the completion of the Offering or other termination of this
Agreement any event shall occur as a result of which it might become necessary
to amend or supplement the Offering Documents so that they do not include any
untrue statement of any material fact or omit to state any material fact
necessary in order to make the statements therein, in the light of the
circumstances then existing, not misleading, the Company will promptly notify
you and will supply you with amendments or supplements correcting such
statement or omission.  The Company will also provide the Placement Agent for
delivery to all offerees and purchasers and their representatives, if any, any
information, documents and instruments which the Placement Agent deems
necessary to comply with applicable state and federal law.

                 (b)      Organization.  Each of the Company and Oncometrics
Imaging Corporation ("Oncometrics") is a corporation duly organized, validly
existing and in good standing under the laws of the jurisdiction of its
incorporation and has all requisite corporate power and authority to own and
lease their respective properties, to carry on its business as currently
conducted and as proposed to be conducted, to execute and deliver this
Agreement and to carry out the transactions contemplated by this Agreement, as
appropriate and is duly licensed or qualified to do business as a foreign
corporation in each jurisdiction in which the conduct of its business or
ownership or leasing of its properties requires it to be so qualified, except
where the failure to so qualify would not have a material adverse effect on the
business of the Company and Oncometrics, taken as a whole.  AccuMed
International Limited ("AccuMed International") is a corporation possessing
substantially the same characteristics under the laws of the United Kingdom.

                 (c)      Capitalization.  The authorized, issued and
outstanding capital stock of the Company prior to the consummation of the
transactions contemplated hereby is as set forth in Exhibit C.  All issued and
outstanding shares of the Company are validly issued, fully paid and
nonassessable and have not been issued in violation of the preemptive rights of
any stockholder of the Company.  All prior sales of securities of the Company
were either registered under the Act and applicable state securities laws or
exempt from such registration, and no security holder has any rescission rights
with respect thereto.





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                 (d)      Warrants, Preemptive Rights, Etc.  Except for the
warrants to purchase shares of Common Stock to be issued to you or your
designees in consideration for your acting as Placement Agent hereunder (the
"Agent's Warrants"), and except as set forth in or contemplated by the Offering
Documents or set forth on Exhibits C and D, there are not, nor will there be
immediately after the Closing (as hereinafter defined), any outstanding
warrants, options, agreements, convertible securities, preemptive rights to
subscribe for or other commitments pursuant to which the Company is, or may
become, obligated to issue any shares of its capital stock or other securities
of the Company and this offering will not cause any anti-dilution adjustments
to such securities or commitments except as reflected in the Term Sheet.

                 (e)      Subsidiaries and Investments.  The Company has no
subsidiaries other than Oncometrics and AccuMed International (the
"Subsidiaries") and the Company does not own, directly or indirectly, any
capital stock or other equity ownership or proprietary interests in any other
corporation, association, trust, partnership, joint venture or other entity.
All of the issued and outstanding capital stock of each of the Subsidiaries has
been duly authorized and validly issued and is fully paid and (except for the
shares of Oncometrics not owned by the Company) is owned by the Company free
and clear of any security interest, mortgage, pledge, lien, encumbrance, claim
or equity.

                 (f)      Financial Statements.  The financial information
contained in the Offering Documents is accurate in all material respects.  The
Company's Form 10-QSB for the nine month period ended September 30, 1996
contains the Company's (i) Balance Sheets at December 31, 1995 and at September
30, 1996 (hereinafter, September 30, 1996 being referred to as the "Balance
Sheet Date"), (ii) Statements of Operations for the three and nine months ended
September 30, 1995, and 1996 and (iii) Statements of Cash Flows for each of the
nine months ended September 30, 1995 and September 30, 1996 (such financial
statements attached to the Offering Documents hereinafter referred to
collectively as the "Financial Statements").  The Financial Statements have
been prepared in conformity with generally accepted accounting principles
consistently applied and show all material liabilities, absolute or contingent,
of the Company required to be recorded thereon and present fairly the financial
position and results of operations of the Company as of the dates and for the
periods indicated.

                 (g)      Absence of Changes.  Since the Balance Sheet Date and
except as described in the Offering Documents or set forth in Exhibit G hereto,
neither the Company nor the Subsidiaries have incurred any liabilities or
obligations, direct or contingent, not in the ordinary course of business, or
entered into any transaction not in the ordinary course of business, which is
material to the business of the Company or the Subsidiaries, and, except as set
forth in Exhibit G to this Agreement and except as described in the Term Sheet,
there has not been any change in the capital stock of, or any incurrence of
long-term debt by, the Company or the Subsidiaries, or any issuance of options,
warrants or other rights to purchase the capital stock of the Company or the
Subsidiaries, or any adverse change or any development involving, so far as the
Company





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can now reasonably foresee, a prospective adverse change in the condition
(financial or otherwise), net worth, results of operations, business, key
personnel or properties which would be material to the business or financial
condition of the Company and the Subsidiaries, taken as a whole, and neither
the Company nor the Subsidiaries has become a party to, and neither the
business nor the property of the Company or the Subsidiaries has become the
subject of, any material litigation whether or not in the ordinary course of
business.

                 (h)      Title.  Except as set forth on Exhibit H hereto, each
of the Company and the Subsidiaries have good and marketable title to all
properties and assets, owned by it, free and clear of all liens, charges,
encumbrances or restrictions, except such as are not materially significant or
important in relation to the Company's or the Subsidiaries' business; all of
the material leases and subleases under which the Company or the Subsidiaries
are the lessor or sublessor of properties or assets or under which the Company
or the Subsidiaries hold properties or assets as lessee or sublessee are in
full force and effect, and neither the Company nor the Subsidiaries are in
default in any material respect with respect to any of the terms or provisions
of any of such leases or subleases, and to the Company's knowledge, no material
claim has been asserted by anyone adverse to rights of the Company or the
Subsidiaries as lessor, sublessor, lessee or sublessee under any of the leases
or subleases mentioned above, or affecting or questioning the right of the
Company or the Subsidiaries to continued possession of the leased or subleased
premises or assets under any such lease or sublease.  Except with respect to
leases and properties related to the ESP Business (as defined in the Term
Sheet), which are subject to closing the Acquisition (as defined in the Term
Sheet), the Company and the Subsidiaries own or lease all such properties as
are necessary to their respective operations as now conducted and to be
conducted, as presently planned.

                 (i)      Proprietary Rights.  Except as set forth in Schedule
I hereto and except as set forth in the Offering Documents, the Company and the
Subsidiaries own or possess adequate and enforceable rights to use all patents,
patent applications, trademarks, service marks, copyrights, trade secrets,
processes, formulations, technology or know-how used or proposed to be used in
the conduct of their respective business as described in the Offering Documents
(the "Proprietary Rights").  Neither the Company nor the Subsidiaries have
received any notice of any claims, nor does the Company have knowledge of any
threatened claims or facts which would form the basis of any claim, asserted by
any person to the effect that the sale or use of any product or process now
used or offered by the Company or the Subsidiaries or proposed to be used or
offered by the Company or the Subsidiaries infringes on any patents or
infringes upon the use of any such Proprietary Rights of another person and, to
the best of the Company's knowledge, no others have infringed the Company's or
the Subsidiaries' Proprietary Rights.

                 (j)      Litigation.  Except as set forth in the Term Sheet,
there is no material action, suit, investigation, customer complaint, claim or
proceeding at law or in equity by or before any arbitrator, governmental
instrumentality or other agency now





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pending or, to the knowledge of the Company, threatened against the Company or
the Subsidiaries the adverse outcome of which would materially adversely affect
the Company's or the Subsidiaries' business or prospects, taken as a whole.
Neither the Company nor the Subsidiaries are subject to any judgment, order,
writ, injunction or decree of any Federal, state, municipal or other
governmental department, commission, board, bureau, agency or instrumentality,
domestic or foreign which would materially adversely affect the Company's and
the Subsidiaries' business or prospects, taken as a whole.

                 (k)      Non-Defaults; Non-Contravention.  Neither the Company
nor the Subsidiaries are in violation of or default under, nor will the
execution and delivery of this Agreement or any of the Offering Documents, the
Notes, the Warrant Agreement, or the Agent's Warrants (as defined herein) or
consummation of the transactions contemplated herein or therein result in a
violation of or constitute a default in the performance or observance of any
obligation (i) under its Certificate of Incorporation, or its By-laws, or any
indenture, mortgage, contract, material purchase order or other agreement or
instrument to which the Company or the Subsidiaries are a party or by which it
or its property is bound or affected or (ii) with respect to any material
order, writ, injunction or decree of any court of any Federal, state, municipal
or other governmental department, commission, board, bureau, agency or
instrumentality, domestic or foreign, and there exists no condition, event or
act which constitutes, nor which after notice, the lapse of time or both, could
constitute a default under any of the foregoing, which in either case would
have a material adverse effect on the business, financial condition or
prospects of the Company and the Subsidiaries, taken as a whole.

                 (l)      Taxes.  The Company has filed all Federal, state,
local and foreign tax returns which are required to be filed by it and all such
returns are true and correct in all material respects.  Except for tax
obligations subject to reasonable dispute by the Company, the Company has paid
all taxes pursuant to such returns or pursuant to any assessments received by
it or which it is obligated to withhold from amounts owing to any employee,
creditor or third party.  The Company has properly accrued all taxes required
to be accrued.  The tax returns of the Company are not currently the subject of
any audit by any state, local or Federal authorities.  The Company has not
waived any statute of limitations with respect to taxes or agreed to any
extension of time with respect to any tax assessment or deficiency.

                 (m)      Compliance With Laws; Licenses, Etc.  Except as set
forth in the Offering Documents, neither the Company nor the Subsidiaries have
received notice of any violation of or noncompliance with any Federal, state,
local or foreign, laws, ordinances, regulations and orders applicable to its
respective business which has not been cured, the violation of, or
noncompliance with which, would reasonably be expected to have a materially
adverse effect on the business or operations of the Company and the
Subsidiaries, taken as a whole.  Each of the Company and the Subsidiaries have
all licenses and permits and other governmental certificates, authorizations
and permits and approvals (collectively, "Licenses") required by every Federal,
state and local government or





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regulatory body for the operation of their respective business as currently
conducted and the use of its properties, except where the failure to be
licensed would not have a material adverse effect on the business of the
Company and the Subsidiaries, taken as a whole.  The Licenses are in full force
and effect and no violations are or have been recorded in respect of any
License and no proceeding is pending or, to the knowledge of the Company,
threatened to revoke or limit any thereof.

                 (n)      Authorization of Agreement, Etc.  This Agreement has
been duly and validly authorized, executed and delivered by the Company and the
execution, delivery and performance by the Company of this Agreement, the
Subscription Agreement, the Escrow Agreement and the Warrant Agreement have
been duly authorized by all requisite corporate action by the Company and when
delivered, constitute or will constitute the legal, valid and binding
obligations of the Company, enforceable in accordance with their respective
terms.

                 (o)      Authorization of Notes and Warrants Etc.  The
issuance, sale and delivery of the Notes and Warrants and the Agent's Warrants
have been duly authorized by all requisite corporate action of the Company.
When so issued, sold and delivered, the Notes and the Warrants will be duly
executed, issued and delivered and will constitute valid and legal obligations
of the Company enforceable in accordance with their respective terms and, in
each case, will not be subject to preemptive or any other similar rights of the
stockholders of the Company or others which rights shall not have been waived
prior to the Initial Closing.

                 (p)      Authorization of Reserved Shares.  Except as
otherwise described in the Term Sheet, the issuance, sale and delivery by the
Company of the shares of Common Stock issuable upon conversion and/or exercise
of the Notes and Warrants including the Agent's Warrants (the "Reserved
Shares") have been duly authorized by all requisite corporate action of the
Company, and the Reserved Shares have been duly reserved for issuance upon
conversion and/or exercise of all or any of the Notes, Warrants and the Agent's
Warrants and when so issued, sold, paid for and delivered, the Reserved Shares
will be validly issued and outstanding, fully paid and nonassessable, and not
subject to preemptive or any other similar rights of the stockholders of the
Company or others which rights shall not have been waived prior to the Initial
Closing.

                 (q)      Exemption from Registration.  Assuming (i) the
accuracy of the information provided by the respective Subscribers in the
Subscription Documents and (ii) that the Placement Agent has complied in all
material respects with the provisions of Regulation D promulgated under the
Securities Act, the offer and sale of the Units pursuant to the terms of this
Agreement are exempt from the registration requirements of the Securities Act
and the rules and regulations promulgated thereunder (the "Regulations").  The
Company is not disqualified from the exemption under Regulation D by virtue of
the disqualifications contained in Rule 505(b)(2)(iii) or Rule 507 promulgated
thereunder.





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                 (r)      Registration Rights.  Except with respect to holders
of the Units and the Agent's Warrants, and except as referenced or described in
the Offering Documents, no person has any right to cause the Company to effect
the registration under the Securities Act of any securities of the Company.

                 (s)      Brokers.  Neither the Company nor any of its
officers, directors, employees or stockholders has employed any broker or
finder in connection with the transactions contemplated by this Agreement other
than the Placement Agent.

                 (t)      Title to Units.  When certificates representing the
securities comprising the Units and/or the Reserved Shares shall have been duly
delivered to the purchasers and payment shall have been made therefor, the
several purchasers shall have good and marketable title to the Notes and
Warrants and/or the Reserved Shares free and clear of all liens, encumbrances
and claims whatsoever (with the exception of claims arising or through the acts
of the purchasers and except as arising from applicable Federal and state
securities laws), and the Company shall have paid all taxes, if any, in respect
of the original issuance thereof.

                 (u)      Right of First Refusal.  Except as set forth on
Schedule U, no person, firm or other business entity is a party to any
agreement, contract or understanding, written or oral entitling such party to a
right of first refusal with respect to the transactions contemplated by this
Agreement, except such as have been waived prior to the Initial Closing Date.

                 (v)      Securities Exchange Act Compliance.  The Company has
filed with the Securities and Exchange Commission ("SEC") on a timely basis all
filings required of a company whose securities have been registered under the
Securities Exchange Act of 1934, as amended ("Exchange Act") during the prior
three years.  All information contained in such filings is true, accurate and
complete in all material respects.  For a period of five years from the date of
this Agreement, the Company covenants to maintain the registration of its
Common Stock under the Exchange Act and to make all filings thereunder on a
timely basis.  For the purpose of this paragraph, filings pursuant to Rule
12b-25 of the Exchange Act shall be deemed timely.

         3.      Closing; Placement and Fees.

                 (a)      Closing.  Provided the Minimum Offering shall have
been subscribed for and funds representing the sale thereof shall have cleared,
a closing (the "Initial Closing") shall take place at the offices of the
Placement Agent, 733 Third Avenue, New York, N.Y. within five (5) days
following the Termination Date (which date (the "Closing Date") may be
accelerated or adjourned by agreement between the Company and the Placement
Agent).  At the Initial Closing, payment for the Units issued and sold by the
Company shall be made against delivery of the Notes and the certificates
representing the Warrants comprising such Units.  In addition, subsequent
closings (if applicable) may be





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scheduled at the discretion of the Company and Placement Agent, each of which
shall be deemed a "Closing" hereunder.

                 (b)      Conditions to Placement Agent's Obligations.  The
obligations of the Placement Agent hereunder will be subject to the accuracy of
the representations and warranties of the Company herein contained as of the
date hereof and as of each Closing Date, to the performance by the Company of
its obligations hereunder and to the following additional conditions:

                          (i)     Due Qualification or Exemption.  (A) The
offering contemplated by this Agreement will become qualified or be exempt from
qualification under the securities laws of the several states pursuant to
paragraph 4(e) below not later than the Closing Date, and (B) at the Closing
Date no stop order suspending the sale of the Units shall have been issued, and
no proceeding for that purpose shall have been initiated or threatened;

                          (ii)    No Material Misstatements.  Neither the Blue
Sky qualification materials nor the Term Sheet, contains an untrue statement of
a fact which in the opinion of the Placement Agent is material, or omits to
state a fact, which in the opinion of the Placement Agent is material and is
required to be stated therein, or is necessary to make the statements therein,
in light of the circumstances under which they were made, not misleading;

                          (iii)   Compliance with Agreements.  The Company will
have complied with all agreements and satisfied all conditions on its part to
be performed or satisfied hereunder at or prior to each Closing;

                          (iv)    Corporate Action.  The Company will have
taken all necessary corporate action, including, without limitation, obtaining
the approval of the Company's board of directors, for the execution and
delivery of this Agreement, the performance by the Company of its obligations
hereunder and the offering contemplated hereby;

                          (v)     Opinion of Counsel.  The Placement Agent
shall receive the opinion of Graham & James LLP, dated the Closing(s),
substantially to the effect that:

                                  (A)      Each of the Company and Oncometrics
has been duly organized and is validly existing and in good standing under the
laws of the State of its incorporation, has all requisite power and authority
necessary to own or hold its properties and conduct its business and is duly
qualified or licensed to do business as a foreign corporation and is in good
standing in each jurisdiction in which the ownership or leasing of its
properties or conduct of its business requires such qualification, except where
the failure to so qualify or be licensed would not have a material adverse
effect on the





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business and condition (financial or otherwise) of the Company; AccuMed
International is a corporation duly organized and validly existing under the
laws of the United Kingdom;

                                  (B)      each of this Agreement, the Notes,
the Warrant Agreement, the Subscription Agreement and the Agent's Warrants has
been duly and validly authorized, executed and delivered by the Company, and is
the valid and binding obligation of the Company, enforceable against it in
accordance with its terms, subject to any applicable bankruptcy, insolvency or
other laws affecting the rights of creditors generally and to general equitable
principles;

                                  (C)      the authorized, issued and
outstanding capital stock of the Company (before giving effect to the
transactions contemplated by this Agreement) is as set forth in the Offering
Documents as of their respective dates.  Except for the Units and Warrants to
be issued as contemplated by this Agreement, to such counsel's knowledge, there
are no outstanding warrants, options, agreements, convertible securities,
preemptive rights or other commitments pursuant to which the Company is, or may
become, obligated to issue any shares of its capital stock or other securities
of the Company other than as set forth in the Term Sheet.  All of the issued
shares of capital stock of the Company have been duly and validly authorized
and issued, are fully paid and nonassessable and have not been issued in
violation of the preemptive rights of any securityholder of the Company.  The
offers and sales during the three years immediately prior to the date hereof of
such outstanding securities were either registered under the Act and applicable
state securities laws or exempt from such registration requirements.  The
Reserved Shares (except as otherwise described in the Term Sheet) have been
duly reserved, and when issued in accordance with the terms of the Notes, the
Warrants and the Agent's Warrants will be validly issued, fully paid and
nonassessable and not subject to preemptive or any other similar rights and no
personal liability will attach to the ownership thereof;

                                  (D)      assuming (i) the accuracy of the
information provided by the Subscribers in the Subscription Documents and (ii)
that the Placement Agent has complied in all material respects with the
requirements of section 4(2) of the Securities Act (and the provisions of
Regulation D promulgated thereunder), the issuance and sale of the Units is
exempt from registration under the Securities Act and Regulation D promulgated
thereunder;

                                  (E)      neither the execution and delivery
of this Agreement, the Notes, the Warrants, the Warrant Agreement, the
Subscription Agreement, or the Agent's Warrants nor compliance with the terms
hereof or thereof, nor the consummation of the transactions herein or therein
contemplated, has, nor will, conflict with, result in a breach of, or
constitute a default under the Certificate of Incorporation or By-laws of the
Company or the Subsidiaries, or, to the best of our knowledge, any material
contract, instrument or document to which the Company or the Subsidiaries are a
party, or by which the Company, the Subsidiaries or any of their respective
properties are bound, or,





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to the best of our knowledge, violate any applicable law, rule, regulation,
judgment, order or decree of any governmental agency or court having
jurisdiction over the Company or the Subsidiaries or any of their respective
properties or businesses;

                                  (F)      to our knowledge, there are no
claims, actions, suits, investigations or proceedings before or by any
arbitrator, court, governmental authority or instrumentality pending or
threatened against or affecting the Company or the Subsidiaries or involving
the properties of the Company or the Subsidiaries which might materially and
adversely affect the business, properties or financial condition of the Company
or the Subsidiaries or which might materially adversely affect the transactions
or other acts contemplated by this Agreement or the validity or enforceability
of this Agreement, except as set forth in or contemplated by the Offering
Documents; and

                                  (G)      such counsel has participated in the
preparation of the Offering Documents and nothing has come to the attention of
such counsel to cause them to have reason to believe that the Offering
Documents contained any untrue statement of a material fact required to be
stated therein or omitted to state any material fact required to be stated
therein or necessary to make the statements therein not misleading (except with
respect to information  concerning Difco, Difco Labs Michigan and Difco Labs
Wisconsin and except for the financial statements, notes thereto and other
financial information and statistical data contained therein, as to which such
counsel need express no opinion).

                          (vi)    Advice of Patent Counsel.  The Placement
Agent shall receive the advice of Graham & James LLP, patent counsel to the
Company, dated the Closing Date, in form and substance satisfactory to the
Placement Agent.

                          (vii)   The Placement Agent shall receive a
certificate of the Company, signed by the President or Chief Financial Officer
and Corporate Vice President and Secretary thereof, that the representations
and warranties contained in Section 2 hereof are true and accurate in all
material respects at such Closing with the same effect as though expressly made
at such Closing.

                          (viii)  Within five days after the Closing, the
Placement Agent shall receive copies of all letters from the Company to the
investors transmitting the Notes and Warrants and shall receive a letter from
the Company confirming transmittal of the securities to the investors.

                          (c)     Blue Sky.  A summary blue sky survey shall be
prepared by counsel to the Company stating the extent to which and the
conditions upon which offers and sales of the Units may be made in certain
jurisdictions.  It is understood that such survey may be based on or rely upon
(i) the representations of each Subscriber set forth in the Subscription
Agreement delivered by such Subscriber, (ii) the representations, warranties
and agreements of the Company set forth in Section 2 of this Agreement, (iii)
the representations and warranties of the Placement Agent, and (iv) the
representations





                                       11
<PAGE>   12
of the Company set forth in the certificate to be delivered at the Closing
pursuant to paragraph (iii) of Section 3(b).

                          (d)     Placement Fee and Expenses.  Simultaneously
with payment for and delivery of the Units at each Closing as provided in
paragraph 3(a) above, the Company shall at such Closing pay to the Placement
Agent (i) a commission equal to seven percent (7%) of the aggregate purchase
price of the Units sold; and (ii) an accountable expense allowance up to
$75,000; provided, however, if such accountable expenses exceed $75,000, such
excess amount shall be reimbursed by the Company upon written approval by the
Company (collectively, the "Transaction Fee").  The Company shall also pay all
expenses in connection with the qualification of the Units under the securities
or Blue Sky laws of the states which the Placement Agent shall designate.  The
Company will, at the Initial Closing, issue to you or your designees (which may
include any Selected Dealer or any officer of the Placement Agent or a Selected
Dealer) the Agent's Warrants in the form annexed hereto as Exhibit 1 to
purchase 200,000 shares of Common Stock.  The Agent's Warrants will be
exercisable for a period of five years from the Initial Closing Date.  The
Placement Agent will be entitled to receive the Transaction Fee whether or not
the Units offered in the Private Placement are sold by the Placement Agent, the
Company or any third party.  Further, if the Company consummates any equity or
debt financing on or after the date of this Agreement, but in no event later
than twelve (12) months after the final closing of the Offering, with any party
initially introduced to the Company by the Placement Agent, the Placement Agent
will be entitled to receive the Transaction Fee in the same proportion to any
such investment in the Company by such party as the Transaction Fee bears to
the Offering.

                          (e)     Bring-Down Opinions and Certificates.  If
there is more than one Closing, then at each such Closing there shall be
delivered to the Placement Agent updated opinions and certificates as described
in (v), (vi) and (vii) of Section 3(b) above, respectively.

                          (f)     No Adverse Changes.  There shall not have
occurred, at any time prior to the Closing or, if applicable, any additional
Closing, (i) any domestic or international event, act or occurrence which has
materially disrupted, or in the Placement Agent's opinion will in the immediate
future materially disrupt, the securities markets; (ii) a general suspension
of, or a general limitation on prices for, trading in securities on the New
York Stock Exchange or the American Stock Exchange or in the over-the-counter
market; (iii) any outbreak of major hostilities or other national or
international calamity; (iv) any banking moratorium declared by a state or
federal authority; (v) any moratorium declared in foreign exchange trading by
major international banks or other persons; (vi) any material interruption in
the mail service or other means of communication within the United States;
(vii) any material adverse change in the business, properties, assets, results
of operations, or financial condition of the Company; or (viii) any change in
the market for securities in general or in political, financial, or economic
conditions which, in the Placement Agent's





                                       12
<PAGE>   13
reasonable judgment, makes it inadvisable to proceed with the offering, sale,
and delivery of the Units.

                 4.       Covenants of the Company.

                          (a)     Use of Proceeds.  The net proceeds of the
Offering will be used by the Company substantially as set forth in the Term
Sheet.  Other than as contemplated in the Term Sheet, the Company shall not use
any of the proceeds from the Offering to repay any indebtedness of the Company,
including but not limited to indebtedness to any current executive officers,
directors or principal stockholders of the Company.

                          (b)     Expenses of Offering.  The Company shall be
responsible for, and shall bear all expenses directly incurred in connection
with, the proposed Offering including, but not limited to, legal fees
(including those of counsel to the Placement Agent) relating to the costs of
preparing the Offering Documents and all amendments, supplements and exhibits
thereto; preparing and delivering all placement agent and selling documents,
including, but not limited to, the Agency Agreement with the Placement Agent
and the blue sky memorandum; Notes and Warrant certificates, blue sky fees,
filing fees and the fees and disbursements of counsel in connection with blue
sky matters (the "Company Expenses").  Such expenses shall not include the cost
of the Placement Agent's reasonable mailing, telephone, telegraph, travel, due
diligence meeting and other similar expenses (the "Placement Agent Expenses")
which are covered by the accountable expense allowance set forth in Section
3(d) above, payable by the Company to the Placement Agent.

                                  If the Private Placement is not completed
because the Company prevents it or because of a breach by the Company of any
such covenants, representations or warranties or, if the Company effects the
contemplated acquisition of the assets from Difco or repays the indebtedness
incurred to effect such transaction without the use of the proceeds
contemplated to be funded in this Offering and the Placement Agent has at least
$7,000,000 in an escrow account, the Company shall pay to the Placement Agent
an amount equal to $300,000 and, in such event, the Placement Agent shall
receive the Agent's Warrants for the purchase of 100,000 shares of Common Stock
of the Company exercisable at the then current market price of the Common
Stock.  In the event that the Company fails to effect the acquisition of the
assets from Difco, and the Placement Agent has at least $7,000,000 in an escrow
account, the Placement Agent will be entitled to receive, at the Company's
option, $300,000 or shares of Common Stock having a then current market value
of $300,000, and the Agent's Warrants to purchase 100,000 shares of Common
Stock exercisable at the then current market price of the Common Stock.

                          (c)     Notification.  The Company shall notify the
Placement Agent immediately, and in writing, (A) when any event shall have
occurred during the period commencing on the date hereof and ending on the
later of the last Closing or the Termination Date as a result of which the
Offering Documents would include any untrue





                                       13
<PAGE>   14
statement of a material fact or omit to state any material fact required to be
stated therein or necessary to make the statements therein not misleading, and
(B) of the receipt of any notification with respect to the modification,
rescission, withdrawal or suspension of the qualification or registration of
the Units, or of any exemption from such registration or qualification, in any
jurisdiction.  The Company will use its best efforts to prevent the issuance of
any such modification, rescission, withdrawal or suspension and, if any such
modification, rescission, withdrawal or suspension is issued and you so
request, to obtain the lifting thereof as promptly as possible.

                          (d)     Blue Sky.  The Company will use its
commercially reasonable efforts to qualify or register the Units for offering
and sale under, or establish an exemption from such qualification or
registration under, the securities or "blue sky" laws of such jurisdictions as
you may reasonably request; provided however, that the Company will not be
obligated to qualify as a dealer in securities or be subject to general service
of process in any jurisdiction in which it is not so qualified or subject.  The
Company will not consummate any sale of Units in any jurisdiction in which it
is not so qualified or in any manner in which such sale may not be lawfully
made.

                          (e)     Form D Filing.  The Company shall file five
copies of a Notice of Sales of Securities on Form D with the Securities and
Exchange Commission (the "Commission") no later than 15 days after the first
sale of the Units.  The Company shall file promptly such amendments to such
Notices on Form D as shall become necessary and shall also comply with any
filing requirement imposed by the laws of any state or jurisdiction in which
offers and sales are made.  The Company shall furnish the Placement Agent with
copies of all such filings.

                          (f)     Press Releases, Etc.  The Company shall not,
during the period commencing on the date hereof and ending on the later of the
last Closing and the Termination Date, issue any press release or other
communication, or hold any press conference with respect to the Company, its
financial condition, results of operations, business, properties, assets, or
liabilities, or the Offering, without the prior consent of the Placement Agent,
which consent shall not be unreasonably withheld unless, in the opinion of
Company's counsel, the press release is required under the securities laws of
the United States.

                          (g)     Form 10-KSB The Company will provide to the
Placement Agent, promptly upon the filing thereof with the Commission (and in
any event no later than 5 days of such filing), a copy of its Annual Report on
Form 10-KSB for the year ended December 31, 1996.

                          (h)     Restrictions on Issuance of Securities.
Prior to the Closing Date, the Company will not, without the prior written
consent of the Placement Agent, issue additional shares of Common Stock or
grant any warrants, options or other securities of the





                                       14
<PAGE>   15
Company except for issuances of shares upon the exercise of outstanding options
and warrants and the issuance of the Bridge Note described in the Term Sheet.

                          (i)     Authorized Capital; Reservation of Common
Stock.  Following the Initial Closing, the Company will use its best efforts to
take all actions as may be necessary (including obtaining stockholder approval)
to amend its Certificate of Incorporation to increase the Company's authorized
shares of Common Stock in order for the Company to have a sufficient number of
authorized shares of Common Stock (after taking into account all shares
reserved for issuance on the conversion of convertible securities and the
exercise of outstanding options and warrants) to permit the issuance of all
shares issuable upon conversion and/or exercise of the Notes, Warrants and the
Agent's Warrants sold in this Offering.  Thereafter, the Company shall reserve
and keep available that maximum number of its authorized but unissued shares of
Common Stock which are issuable upon conversion and/or exercise of the Notes
and Warrants, including the shares underlying the Agent's Warrants.


                 5.       Indemnification.

                          (a)     (i)      The Company agrees to indemnify and
hold harmless the Placement Agent and its shareholders, directors, officers,
agents and controlling persons (an "Indemnified Party") against any and all
loss, liability, claim, damage and expense whatsoever (and all actions in
respect thereof), and to reimburse the Placement Agent for legal fees and
related expenses as incurred (including, but not limited to the costs of giving
testimony or furnishing documents in response to a subpoena or otherwise, and
the costs of investigating, preparing or defending any such action or claim
whether or not in connection with litigation in which the Placement Agent is a
party), arising out of any untrue statement or alleged untrue statement of a
material fact contained in the Offering Documents or the omission or alleged
omission therefrom of a material fact necessary in order to make the statements
therein, in light of the circumstances under which they were made, not
misleading;

                                  (ii)     The Placement Agent agrees to
indemnify and hold harmless the Company and its respective shareholders,
directors, officers, agents and controlling persons against any and all loss,
liability, claim, damage and expense whatsoever (and all actions in respect
thereof), and to reimburse the Company for legal fees and related expenses
(including, but not limited to the costs of giving testimony or furnishing
documents in response to a subpoena or otherwise, and the costs of
investigating, preparing or defending any such action or claim whether or not
in connection with litigation in which the Placement Agent is a party), arising
out of any untrue statement or alleged untrue statement of a material fact
contained in the Offering Documents or the omission or alleged omission
therefrom of a material fact necessary in order to make the statements therein,
in light of the circumstances under which they were made, not misleading, to
the





                                       15
<PAGE>   16
extent, but only to the extent, that such untrue statement or omission is
contained in any information so furnished in writing by the Placement Agent to
the Company specifically for inclusion in the Offering Documents.  In no event
shall the liability of the Placement Agent hereunder be greater in amount than
the dollar amount of the proceeds of this Offering.

                          (b)     The Company agrees to indemnify and hold
harmless an Indemnified Party to the same extent as the foregoing indemnity,
against any and all loss, liability, claim, damage and expense whatsoever
directly arising out of the exercise by any person of any right under the
Securities Act or the Exchange Act or the securities or Blue Sky laws of any
state on account of violations of the representations, warranties or agreements
set forth in Section 2 hereof.

                          (c)     Promptly after receipt by a person entitled
to indemnification pursuant to the foregoing subsection (a) or (b) under this
Section of notice of the commencement of any action, the indemnified party
will, if a claim in respect thereof is to be made against the Indemnifying
party under this Section, notify in writing the indemnifying party of the
commencement thereof; but the omission so to notify the indemnifying party will
not relieve it from any liability which it may have to the indemnified party
otherwise than under this Section.  In case any such action is brought against
an indemnified party, and it notifies the indemnifying party of the
commencement thereof, the indemnifying party will be entitled to participate
in, and, to the extent that it may wish, jointly with any other indemnifying
party similarly notified, to assume the defense thereof, subject to the
provisions herein stated, with counsel reasonably satisfactory to the
indemnified party, and after notice from the indemnifying party to the
indemnified party of its election so to assume the defense thereof, the
indemnifying party will not be liable to the indemnified party under this
Section for any legal or other expenses subsequently incurred by the
indemnified party in connection with the defense thereof other than reasonable
costs of investigation.  The indemnified party shall have the right to employ
separate counsel in any such action and to participate in the defense thereof,
but the fees and expenses of such counsel shall not be at the expense of the
indemnifying party if the indemnifying party has assumed the defense of the
action with counsel reasonably satisfactory to the indemnified party; provided
that the fees and expenses of such counsel shall be at the expense of the
Indemnifying party if (i) the employment of such counsel has been specifically
authorized in writing by the indemnifying party or (ii) the named parties to
any such action (including any impleaded parties) include both the indemnified
party or parties and the indemnifying party and, in the judgment of the
indemnified party, it is advisable for the indemnified party or parties to be
represented by separate counsel (in which case the indemnifying party shall not
have the right to assume the defense of such action on behalf of the
indemnified party or parties, it being understood, however, that the
indemnifying party shall not, in connection with any one such action or
separate but substantially similar or related actions in the same jurisdiction
arising out of the same general allegations or circumstances, be liable for the
reasonable fees and expenses of more than one separate firm of attorneys for
the indemnified party or parties.  No settlement of any action against an
indemnified party shall be made without the consent of the





                                       16
<PAGE>   17
indemnified party, which shall not be unreasonably withheld in light of all
factors of importance to the indemnified party.

         6.      Contribution.

                 To provide for just and equitable contribution, if (i) an
indemnified party makes a claim for indemnification pursuant to Section (5) but
it is found in a final judicial determination, not subject to further appeal,
that such indemnification may not be enforced in such case, even though this
Agreement expressly provides for indemnification in such case, or (ii) any
indemnified or indemnifying party seeks contribution under the Securities Act,
the Exchange Act, or otherwise, then the Company (including for this purpose
any contribution made by or on behalf of any officer, director, employee or
agent for the Company, or any controlling person of the Company), on the one
hand, and the Placement Agent and any Selected Dealers (including for this
purpose any contribution by or on behalf of an indemnified Party), on the other
hand, shall contribute to the losses, liabilities, claims, damages, and
expenses whatsoever to which any of them may be subject, in such proportions as
are appropriate to reflect the relative benefits received by the Company, on
the one hand, and the Placement Agent and the Selected Dealers, on the other
hand; provided, however, that if applicable law does not permit such
allocation, then other relevant equitable considerations such as the relative
fault of the Company and the Placement Agent and the Selected Dealers in
connection with the facts which resulted in such losses, liabilities, claims,
damages, and expenses shall also be considered.  In no case shall the Placement
Agent or a Selected Dealer be responsible for a portion of the contribution
obligation in excess of the compensation received by it pursuant to Section 3
hereof or the Selected Dealer Agreement, as the case may be.  No person guilty
of a fraudulent misrepresentation shall be entitled to contribution from any
person who is not guilty of such fraudulent misrepresentation.  For purposes of
this Section 6, each person, if any, who controls the Placement Agent within
the meaning of Section 15 of the Securities Act or Section 20(a) of the
Exchange Act and each officer, director, stockholder, employee and agent of the
Placement Agent, shall have the same rights to contribution as the Placement
Agent, and each person, if any who controls the Company within the meaning of
Section 15 of the Securities Act or Section 20(a) of the Exchange Act and each
officer, director, employee and agent of the Company, shall have the same
rights to contribution as the Company, subject in each case to the provisions
of this Section 6.  Anything in this Section 6 to the contrary notwithstanding,
no party shall be liable for contribution with respect to the settlement of any
claim or action effected without its written consent.  This Section 6 is
intended to supersede any right to contribution under the Securities Act, the
Exchange Act, or otherwise.

         7.      Miscellaneous.

                 (a)      Survival.  Any termination of the Offering without
consummation thereof shall be without obligation on the part of any party
except that the





                                       17
<PAGE>   18
indemnification provided in Section 5 hereof and the contribution provided in
Section 6 hereof shall survive any termination and shall survive the Closing
for a period of five years.

                 (b)      Representations, Warranties and Covenants to Survive
Delivery.  The respective representations, warranties, indemnities, agreements,
covenants and other statements of the Company as of the date hereof shall
survive execution of this Agreement and delivery of the Units and the
termination of this Agreement.

                 (c)      No Other Beneficiaries.  This Agreement is intended
for the sole and exclusive benefit of the parties hereto and their respective
successors and controlling persons, and no other person, firm or corporation
shall have any third-party beneficiary or other rights hereunder.

                 (d)      Governing Law.  This Agreement shall be governed by
and construed in accordance with the law of the State of New York without
regard to conflict of law provisions.

                 (e)      Counterparts.  This Agreement may be signed in
counterparts with the same effect as if both parties had signed one and the
same instrument.

                 (f)      Notices.  Any communications specifically required
hereunder to be in writing, if sent to the Placement Agent, will be mailed,
delivered and confirmed to it at Commonwealth Associates, 733 Third Avenue, New
York, New York  10017, Att:  Keith Rosenbloom, Esq., with a copy to Bachner,
Tally, Polevoy & Misher LLP, 380 Madison Avenue, New York, New York  10017,
Att: Alison S. Newman, Esq. and if sent to the Company, will be mailed,
delivered or telegraphed and confirmed to it at AccuMed International, Inc.,
900 North Franklin Street, Suite 401, Chicago, IL  60610, Att: Peter P.
Gombrich, with a copy to AccuMed International, Inc., 1500 Seventh Avenue,
Sacramento, CA 95818, Attn:  Joyce Wallach, General Counsel and to Graham &
James LLP, 400 Capitol Mall, Sacramento, CA 95814-4602, Attn: Kevin Coyle,
Esq..

                 (g)      Entire Agreement.  This Agreement constitutes the
entire agreement of the parties with respect to the matters herein referred and
supersedes all prior agreements and understandings, written and oral, between
the parties with respect to the subject matter hereof.  Neither this Agreement
nor any term hereof may be changed, waived or terminated orally, but only by an
instrument in writing signed by the party against which enforcement of the
change, waiver or termination is sought.





                                       18
<PAGE>   19
         If you find the foregoing is in accordance with our understanding,
kindly sign and return to us a counterpart hereof, whereupon this instrument
along with all counterparts will become a binding agreement between us.

                                        Very truly yours,

                                        ACCUMED INTERNATIONAL, INC.


                                        By:  /s/ Leonard R. Prange
                                             -----------------------------------
                                             Title: Corporate Vice President and
                                             Chief Financial Officer


Agreed:

COMMONWEALTH ASSOCIATES


By:  /s/ Basil Asciutto
     -----------------------------
     Authorized Officer





                                       19
<PAGE>   20
                                   SCHEDULE A

                          AccuMed INTERNATIONAL, INC.

                                     Units


                      PRIVATE PLACEMENT SELLING AGREEMENT

                                                             New York, New York
                                                                    , 1997


[           ]

Dear Sirs:

         1.      AccuMed International, Inc. (the "Company") is offering for
sale on a "best efforts, all or none" basis, a total of up to eighty-five (85)
Units.  The Units and the terms under which they are to be offered for sale by
the Company are more particularly described in the Confidential Term Sheet
dated             , 1997 (the "Term Sheet") and the form of subscription
agreement between the Company and each subscriber (the "Subscription
Agreement"), the exhibits to the Term Sheet and the Subscription Agreement, and
any other documents delivered to subscribers (herein, collectively the
"Offering Documents").  Commonwealth Associates (the "Placement Agent") has
agreed to act as exclusive placement agent to the Company for the purpose of
assisting the Company in finding subscribers who satisfy the requirements set
forth in the Offering Documents and more particularly in the Subscription
Agreement (herein, "Qualified Subscribers") pursuant to the offering ("Private
Placement") described in the Offering Documents.

         2.      The Units are to be offered to a limited number of subscribers
by the Company at the price per Unit set forth in the Offering Documents (the
"Subscription Price"), in accordance with the terms of offering thereof set
forth in the Offering Documents.

         3.      We are extending the right, subject to the terms and conditions
hereof, to assist the Company in finding Qualified Subscribers to purchase a
portion of the Units, to certain dealers who are actually engaged in the
investment banking or securities business and who are members in good standing
of the National Association of Securities Dealers, Inc. (the "NASD") (such
dealers who shall agree to assist in locating Qualified Subscribers for Units
hereunder being herein called "Selected Dealers"), at the Subscription Price,
for which they will receive a commission of ____% of the Subscription Price for
Units purchased by Qualified Subscribers presented to the Company by them.  The
Selected 





<PAGE>   21
Dealers have agreed to comply with the provisions of all applicable Rules of
Fair Practice of the NASD.  We may be included among the Selected Dealers.

         4.      We shall have full authority to take such action as we may
deem advisable in respect of all matters pertaining to the Private Placement of
the Units.

         5.      If you desire to present to the Company any Qualified
Subscribers for Units, your application should reach us promptly by telephone
or telegraph at 733 Third Avenue, New York, New York  10007, Attention:
__________________________, telephone number 212-297-7000.  We reserve the
right to reject subscriptions in whole or in part, to make allotments and to
close the subscription books at any time without notice.  The Units allotted to
the Qualified Subscribers presented by you will be confirmed, subject to the
terms and conditions of this Agreement.

         6.      The privilege of assisting the Company in finding Qualified
Subscribers for the Units is extended to you only so long as the Company may
lawfully sell the Units to residents in the state in which any such Qualified
Subscribers reside pursuant to the terms of the Offering Documents.

         7.      Any Units offered under the terms of this Agreement and the
Offering Documents may only be offered and sold subject to the securities or
blue sky laws of the various states or other jurisdictions.

         You agree to advise us from time to time, upon request, of the number
of sets of Offering Documents delivered to qualified subscribers by you
hereunder at the time of such request.

         No expenses shall be charged to Selected Dealers.

         Neither you nor any other person is or has been authorized to give any
information or to make any representation in connection with the offer or sale
of the Units other than as contained in the Offering Documents.

         8.      On becoming a Selected Dealer, and in assisting the Company in
finding Qualified Subscribers for the Units, you agree to comply with all the
applicable requirements of the Securities Act of 1933, as amended (the "1933
Act") specifically with respect to the requirements of Regulation D thereunder.
You confirm that you are familiar with Rules 501 and 502 under the 1933 Act
relating to the limitations on the manner in which a private placement may be
conducted pursuant to Regulation D under the 1933 Act.

         9.      Upon request, you will be informed as to the states and other
jurisdictions in which we have been advised that the Units have been qualified
or are exempt from registration requirements for offer and sale under the
respective securities or blue sky laws of such states and other jurisdictions,
but we do not assume any obligation or





                                       2
<PAGE>   22
responsibility as to the right of any Selected Dealer to offer the Units in any
state or other jurisdiction or as to the eligibility of the Units for sale
therein.  We will, if requested, file a Further State Notice in respect of the
Units pursuant to Article 23-A of the General Business Law of the State of New
York.

         10.     No Selected Dealer is authorized to act as our agent or an
agent of the Company or otherwise to act on our behalf in assisting the Company
in finding Qualified Subscribers or otherwise or to furnish any information or
make any representation except as contained in the Offering Documents.

         11.     Nothing will constitute the Selected Dealers an association or
other separate entity or partners with us, or with each other, but you will be
responsible for your share of any liability or expense based on any claim to
the contrary.  We shall not be under any liability for or in respect of value,
validity or form of the components of the Units or the delivery of the Notes
and Warrants comprising the Units, or the performance by anyone of any
agreement on its part, or the qualification of the Units for offer or sale
under the laws of any jurisdiction, or for or in respect of any other matter
relating to this Agreement, except for lack of good faith and for obligations
expressly assumed by us in this Agreement and no obligation on our part shall
be implied herefrom.  The foregoing provisions shall not be deemed a waiver of
any liability imposed under the federal securities laws.

         12.     Payment for the Units subscribed for hereunder is to be made
by Qualified Subscribers at the Subscription Price during the term of the
Private Placement set forth in the Offering Documents at the office of
Commonwealth Associates, 733 Third Avenue, New York, New York 10017, by a
certified or official bank check, payable to the order of [Escrow Agent name
and account].

         13.     Notice to us should be addressed to Commonwealth Associates,
733 Third Avenue, New York, New York  10017, Attention: __________________.
Notices to you shall be deemed to have been duly given if mailed to you at the
address to which this letter is addressed.

         14.     If you desire to assist the Company in finding Qualified
Subscribers pursuant to the terms set forth above, please confirm your
application by signing and returning to us your confirmation on the duplicate
copy of this letter enclosed herewith, even though you may have previously
advised us thereof by telephone or telegraph.  Our signature hereon may be by
facsimile.

                                        Very truly yours,

                                        COMMONWEALTH ASSOCIATES


                                        By: 
                                            -----------------------------------
                                             Authorized Officer





                                       3
<PAGE>   23





                 We hereby present to AccuMed International, Inc. (the
"Company") Qualified Subscribers for Units in accordance with the terms and
conditions stated in the foregoing letter.  We hereby acknowledge receipt of
the Offering Documents referred to in the first paragraph thereof relating to
said Units.  We confirm that we are a dealer actually engaged in the investment
banking or securities business and that we are a member in good standing of the
National Association of Securities Dealers, Inc. (the "NASD").  We hereby agree
to comply with all of the applicable provisions of the Rules of Fair Practice
of the NASD.




                                        By:
                                             ----------------------------------
                                             Authorized Officer





Dated:  ________________________