KEY EMPLOYEE AGREEMENT
                           ----------------------

To:    Carl Franzblau, Ph.D.
       147 Plymouth Road
       Newton, Massachusetts  02161

                                                    May 18, 1999

The undersigned, Hemagen Diagnostics, Inc., a Delaware corporation (the
"Company"), hereby agrees with you as follows:

1.    Position and Responsibilities.
      ------------------------------

1.    1.1  You shall serve as Chief Executive Officer and President for the
Company, (or in such other executive capacity as shall be designated by the
Board of Directors and reasonably acceptable to you in your sole discretion)
and shall perform the duties customarily associated with such capacity from
time to time as the Company shall designate are appropriate and necessary in
connection with such employment.

      1.2  You will, to the best of your ability, devote no less than thirty
(30) hours per week to the performance of your duties hereunder and to the
business and affairs of the Company. You agree to perform such executive
duties as may be assigned to you by or on authority of the Company's Board of
Directors from time to time.

      1.3  You will perform and observe any and all reasonable rules and
regulations which the Company may now or shall hereafter establish governing
the conduct of its business.

      1.4  If, for any reason, the Company materially or substantially changes
or modifies your duties and/or the responsibilities of your position with the
Company or if the Company relocates your primary place of employment to a
place that is greater than 50 miles from its present location in Waltham,
Massachusetts, then, at your option, your employment with the Company may be
terminated and, for purposes of  this Agreement, such termination will be
considered a termination without cause by the Company and the provisions of
Section 2.2(b) shall apply.

2.    Term of Employment.
      -------------------

      2.1 The initial term of this Agreement shall be for the period of years
set forth on Exhibit A annexed hereto commencing May 18, 1999. Thereafter,
this Agreement shall be automatically renewed for successive periods of one
year, unless you or the Company shall give the other party not less than nine
(9) months written notice of non-renewal. Your employment with the Company may
be terminated at any time as provided in section 2.2.

       2.2  The Company shall have the right, on written notice to you, to
terminate your employment:

            (a) immediately at any time for cause; or

            (b) at any time without cause, provided the Company shall be
      obligated to pay to you as severance pay an amount equal to thirty-six
      (36) months Base Salary (as set forth on Exhibit A hereto regardless of
      the remaining term hereunder) , less applicable taxes and other required
      withholdings and any amounts you may owe to the Company; or

            (c) at any time without cause or notice in the event of any
      involuntary liquidation of the Company.

      2.3  For purposes of Section 2.2, the term "cause" shall mean the
willful breach or habitual neglect of your obligations under this Agreement or
your duties as an employee of the Company provided that, if time allows, the
Company provides you with thirty (30) days prior notice with the right to cure
such breach or neglect.

      2.4 For purposes of Section 2.2(b), you shall have no duty to mitigate
such payments by seeking other employment nor shall any payments be reduced by
any other employment which you may obtain after termination of your employment
with the Company.  However, if you accept any payments under Section 2.2(b),
you shall hereby agree (and you hereby agree to sign any reasonable general
release form) to release and hold the Company harmless from and against any
claim or action you may have against the Company related solely to your
employment by the Company.

3.    Compensation. You shall receive the compensation and benefits set forth
on Exhibit A hereto ("Compensation") for all services to be rendered by you
hereunder and for your transfer of property rights pursuant to an agreement
relating to proprietary information and inventions of even date herewith
attached hereto as Exhibit B between you and the Company (the "Proprietary
Information and Inventions Agreement").

4.    Other Activities During Employment.  You hereby agree that during your
employment hereunder, you will not, directly or indirectly, engage (a)
individually, (b) as an officer, (c) as a director, (d) as an employee, (e) as
a consultant, (f) as an advisor, (g) as an agent (whether a salesperson or
otherwise) , (h) as a broker, or (I) as a partner, co-venturer, stockholder or
other proprietor owning directly or indirectly more than five percent (5%)
interest in any firm, corporation, partnership, trust, association, or other
organization which is engaged in the manufacture and sale of medical
diagnostics or any other line of business engaged in or under demonstrable
development by the Company (such firm, corporation, partnership, trust,
association, or other organization being hereinafter referred to as a
"Prohibited Enterprise").

5.   Former Employers.
     -----------------

      5.1  You represent and warrant that your employment by the Company will
not conflict with and will not be constrained by any prior or current
employment, consulting agreement or relationship whether oral or written. You
represent and warrant that you do not possess confidential information arising
out of any such employment, consulting agreement or relationship which, in
your best judgment, would be utilized in connection with your employment by
the Company in the absence of Section 5.2.

      5.2  If, in spite of the second sentence of Section 5.1, you should find
that confidential information belonging to any other person or entity might be
usable in connection with the Company's business, you will not intentionally
disclose to the Company or use on behalf of the Company any confidential
information belonging to any of your former employers; but during your
employment by the Company you will use in the performance of your duties all
information which is generally known and used by persons with training and
experience comparable to your own all information which is common knowledge in
the industry or otherwise legally in the public domain.

6.    Proprietary Information and Inventions. You agree to execute, deliver
and be bound by the provisions of the Proprietary Information and Inventions
Agreement.

7.    Post-Employment Activities.
      ---------------------------

      7.1  For a period of one (1) year after the termination or expiration,
for any reason, of your employment with the Company hereunder, absent the
Company's prior written approval, you will not directly or indirectly engage
in activities similar or reasonably related to those in which you shall have
engaged hereunder during the one year immediately preceding termination or
expiration for, nor render services similar or reasonably related to those
which you shall have rendered hereunder during such year to, any person or
entity whether now existing or hereafter established which directly competes
with (or proposes or plans to directly compete with) the Company ("Direct
Competitor") in any line of business engaged in or under development by the
Company. Nor shall you entice, induce or encourage any of the Company's other
employees to engage in any activity which, were it done by you, would violate
any provision of the Proprietary Information and Inventions Agreement or this
Section 7. As used in this Section 7.1, the term "any line of business engaged
in or under development by the Company" shall be applied as at the date of
termination of your employment, or, if later, as at the date of termination of
any post-employment consultation.

      7.2  No provision of this Agreement shall be construed to preclude you
from performing the same services which the Company hereby retains you to
perform for any person or entity which is not a Direct Competitor of the
Company upon the expiration or termination of your employment (or any post-
employment consultation) so long as you do not thereby violate any term of the
Proprietary Information and Inventions Agreement.

8.    Remedies. Your obligations under the Proprietary Information and
Inventions Agreement and the provisions of Sections 6,7,8 and 9 of this
Agreement (as modified by Section 10, if applicable) shall survive the
expiration or termination of your employment (whether through your resignation
or otherwise) with the Company. You acknowledge that a remedy at law for any
breach or threatened breach by you of the provisions of the Proprietary
Information and Inventions Agreement or Section 7 would be inadequate and you
therefore agree that the Company shall be entitled to such injunctive relief
in case of any such breach or threatened breach.

9.    Assignment. This Agreement and the rights and obligations of the parties
hereto shall bind and inure to the benefit of any successor or successors of
the Company by reorganization, merger or consolidation and any assignee of all
or substantially all of its business and properties, but, except as to any
such successor or assignee of the Company, neither this Agreement nor any
rights or benefits hereunder may be assigned by the Company or by you, except
by operation of law.

10.   Interpretation.  IT IS THE INTENT OF THE PARTIES THAT in case any one or
more of the provisions contained in this Agreement shall, for any reason, be
held to be invalid, illegal or unenforceable in any respect, such invalidity,
illegality or unenforceability shall not affect the other provisions of this
Agreement, and this Agreement shall be construed as if such invalid, illegal
or unenforceable provision had never been contained herein. MOREOVER, IT IS
THE INTENT OF THE PARTIES THAT in case any one or more of the provisions
contained in this Agreement shall for any reason be held to be excessively
broad as to duration, geographical scope, activity or subject, such provision
shall be construed by limiting and reducing it as determined by a court of
competent jurisdiction, so as to be enforceable to the extent compatible with
applicable law.

11.   Notices.  Any notice which the Company is required to or may desire to
give you shall be given by personal delivery or registered or certified mail,
return receipt requested, addressed to you at your address of record with the
Company, or at such other place as you may from time to time designate in
writing. Any notice which you are required or may desire to give to the
Company hereunder shall be given by personal delivery or by registered or
certified mail, return receipt requested, addressed to the Company at its
principal office, or at such other office as the Company may from time to time
designate in writing. The date of personal delivery or the date of mailing any
notice under this Section 11 shall be deemed to be the date of delivery
thereof.

12.   Waivers.  If either party should waive any breach of any provision of
this Agreement, such party shall not thereby be deemed to have waived any
preceding or succeeding breach of the same or any other provision of this
Agreement.

13.   Complete Agreement; Amendments.  The foregoing including Exhibits A, B
and C hereto, is the entire agreement of the parties with respect to the
subject matter hereof, superseding any previous oral or written
communications, representations, understandings, or agreements with the
Company or any officer or representative thereof. Any amendment to this
Agreement or waiver by the Company of any right hereunder shall be effective
only if evidenced by a written instrument executed by the parties hereto, upon
authorization of the Company's Board of Directors.

14.   Headings.  The headings of the Sections hereof are inserted for
convenience only and shall not be deemed to constitute a part hereof nor to
affect the meaning of this Agreement.

15.   Counterparts.  This Agreement may be signed in two counterparts, each of
which shall be deemed an original and both of which shall together constitute
one agreement.

16.   Governing Law.  This Agreement shall be governed by and construed under
Massachusetts law.

      If you are in agreement with the foregoing, please sign your name below
and also at the bottom of the Proprietary Information and Inventions
Agreement, whereupon this Agreement shall become binding in accordance with
its terms. Please then return this Agreement to the Company. (You may retain
for your records the accompanying counterpart of this Agreement enclosed
herewith).

                                       Very truly yours,
                                       HEMAGEN DIAGNOSTICS INC.


                                       By: /s/ Lawrence Gilbert, Member of the
                                       Compensation Committee of the Board of
                                       Directors

Accepted and Agreed: /s/ Carl Franzblau
                     ------------------
                         CARL FRANZBLAU


                                  Exhibit A
                                  ---------

                 EMPLOYMENT TERM, COMPENSATION AND BENEFITS

                              OF CARL FRANZBLAU

2.    Term.  The term of the Agreement to which this Exhibit A is annexed and
      incorporated shall be until May 17, 2004.

2.    Compensation.
      -------------
            (a) Base Salary. Your Base Salary shall be:
      $145,000 per annum from the date of this Agreement through the
      remainder of 1999 and thereafter as may be determined by the Company's
      Board of Directors, but in no event less than $145,000 per annum,
      payable in accordance with the Company's payroll policies.

            (b) Bonus.  Any future bonuses shall be determined by the Board of
      Directors of the Company, taking into account the current economic
      condition of the Company.

3.    Vacation.  You shall be entitled to all legal and religious holidays,
      and five (5) weeks paid vacation per annum.

4.    Insurance and Benefits. You shall be eligible for participation in any
      health or other group insurance plan or general benefit plans which may
      be established by the Company or which the Company is required to
      maintain by law. The Company shall provide health insurance for you and
      your family. You shall also be entitled to use an automobile provided by
      the Company.

                                  Exhibit B
                                  ---------

              PROPRIETARY INFORMATION AND INVENTIONS AGREEMENT

To:   Hemagen Diagnostics, Inc.
      34-40 Bear Hill Road
      Waltham, Massachusetts 02451

                                                    As of May 18, 1998

      The undersigned, in consideration of and as a condition of my employment
or continued employment by you and/or by companies which you own, control, or
are affiliated with or their successors in business (collectively, the
"Company"), hereby agrees as follows:

1.    Confidentiality.  I agree to keep confidential, except as the Company
may otherwise consent in writing, and, except for the Company's benefit, not
to disclose or make any use of at any time either during or subsequent to my
employment, any Inventions (as hereinafter defined), trade secrets,
confidential information, knowledge, data or other information of the Company
relating to products, processes, know-how, designs, formulas, test data,
customer lists, business plans, marketing plans and strategies, pricing
strategies, or other subject matter pertaining to any business of the Company
or any of its affiliates, which I may produce, obtain, or otherwise acquire
during the course of my employment, except as herein provided. I further agree
not to deliver, reproduce or in any way allow any such trade secrets,
confidential information, knowledge, data or other information, or any
documentation relating thereto, to be delivered to or used by any third
parties without specific direction or consent of a duly authorized
representative of the Company.

2.    Conflicting Employment: Return of Confidential Material.
      --------------------------------------------------------

      2.1  I agree that during my employment with the Company I will not
engage in any other employment, occupation, consulting or other activity
relating to the business in which the Company is now or may hereafter become
engaged, or which would otherwise conflict with my obligations to the Company.
In the event my employment with the Company terminates for any reason
whatsoever, I agree to promptly surrender and deliver to the Company all
records, materials, equipment, drawings, documents and data of which I may
obtain or produce during the course of my employment, and I will not take with
me any description containing or pertaining to any confidential information,
knowledge or data of the Company which I may produce or obtain during the
course of my employment.

      2.2  I represent that I am not a party to any existing Agreement which
would prevent my entering into this Agreement, but advise the Company that I
am a member of the Academic Staff of Boston University ("University").  As a
member of the Academic Staff, I am responsible for ensuring that any agreement
I enter into is not in conflict with the patent policy of the University or in
conflict with other University commitments. Under my University Patent Policy
and Agreement, I am required to disclose to the University certain inventions
made by me in the course of my outside employment or consulting work that
directly relate to my professional work at the University. Should University
facilities be used by me in the reduction to practice of such inventions,
paragraph 2.6 below shall apply, otherwise paragraph 2.5 below shall apply. I
agree to use my best efforts to (a) segregate work done under this Agreement
from my work for the University, so as to minimize any questions of disclosure
of, or rights under, any inventions, and (b) assist the Company and the
University in fairly resolving any such questions which may arise.

       2.3  I also acknowledge that the University has accepted certain grants
under  research funding agreements with the following Government agencies
pursuant to which I perform basic research: NIH (HL) and NIH (AG)
("Government"). Work on said Government funded research project(s) will
continue during the term of this Agreement, but do not relate to the business
of the Company. As a result of the Government funding agreements, I am
required to disclose to the University certain inventions made by me in the
course of my work that may relate also to my research work under the
Government funding agreements. I agree to use my best efforts to (a) segregate
work done under this Agreement from my work under the Government funding
agreement, so as to minimize any questions of disclosure of, or rights under,
any inventions, and (b) assist the Company, the Government and, if necessary,
the University in fairly resolving any such questions which may arise.

      2.4  I warrant that I am not obligated under any other consultant,
employment, or other agreement which would affect the Company's rights or my
duties under this Agreement. I agree that for the term of this Agreement, and
for a period of two (2) years thereafter, I will not, without the prior
written consent of the Company, enter into any agreement with anyone other
than the Company to consult or otherwise render services with regard to the
subject matter of this Agreement or any subject directly relevant thereto,
provided that this Agreement shall not negate my obligations to the
University.

      2.5  Except as hereinafter provided, any and all improvements,
developments, or discoveries or inventions that are made by me or as a direct
result of my employment by the Company, whether or not patentable, shall be
the sole and exclusive property of the Company. I agree to disclose promptly
to the Company any such improvements, developments, or discoveries made by me,
and, where applicable, to assign to the Company any inventions disclosed and
to give the Company reasonable assistance in preparing or prosecuting, in the
Company's name and at the Company's expense, any patent applications covering
such inventions.

      2.6  Any invention made by me that is reduced to practice using
University facilities may be subject to certain rights of the University. The
University's policy states that for three years after disclosure by me of
inventions that are subject to such rights, the University may not to grant
any rights under patents or patent applications covering such inventions
without first offering the Company or myself the opportunity for sixty (60)
days from the date of the offer to meet the terms of such proposed grant of
rights.

      2.7  I hereby represent and warrant that the work to be performed by me
for the Company, which is subject to this Agreement, does not relate to my
work at the University and is not subject to any claims of the University.

3.    Assignment of Inventions.
      -------------------------

      3.1  I hereby acknowledge and agree that the Company is the owner of all
Inventions. In order to protect the Company's rights to such Inventions, by
executing this Agreement I hereby irrevocably assign to the Company all my
right, title and interest in and to all Inventions.

      3.2  For purposes of this Agreement, "Inventions" shall mean all
discoveries, processes, designs, technologies, devices, or improvements in any
of the foregoing or other ideas, whether or not patentable and whether or not
reduced to practice, made or conceived by me (whether solely or jointly with
others) during the period of my employment with the Company which relate in
any manner to the actual or demonstrably anticipated business, work, or
research and development of the Company, or result from or are suggested by
any task assigned to me or any work performed by me for or on behalf of the
Company.

      3.3  Any discovery, process, design, technology, device, or improvement
in any of the foregoing or other ideas, whether or not patentable and whether
or not reduced to practice, made or conceived by me (whether solely or jointly
with others) which I develop entirely on my own time not using any of the
Company's equipment, supplies, facilities, or trade secret information
("Personal Invention") is excluded from this Agreement provided such Personal
Invention (a) does not relate to the actual or demonstrably anticipated
business' research and development of the Company, and (b) does not result,
directly or indirectly, from any work performed by me for the Company.

4.    Disclosure of Inventions.  I agree that in connection with any
Invention, I will promptly disclose such Invention to my immediate superior at
the Company in order to permit the Company to enforce its property rights to
such Invention in accordance with this Agreement. My disclosure shall be
received in confidence by the Company.

5.    Patents and Copyrights; Execution of Documents.
      -----------------------------------------------

      5.1  Upon request, I agree to assist the Company or its nominee (at its
expense) during and at any time subsequent to my employment in every
reasonable way to obtain for its own benefit patents and copyrights for
Inventions in any and all countries. Such patents and copyrights shall be and
remain the sole and exclusive property of the Company or its nominee. I agree
to perform such lawful acts as the Company deems to be necessary to allow it
to exercise all right, title and interest in and to such patents and
copyrights.

      5.2  In connection with this Agreement, I agree to execute, acknowledge
and deliver to the Company or its nominee upon request and at its expense all
documents, including assignments of title, patent or copyright applications,
assignments of such applications, assignments of patents or copyrights upon
issuance, as the Company may determine necessary or desirable to protect the
Company's or its nominee's interest in Inventions, and/or to use in obtaining
patents or copyrights in any and all countries and to vest title thereto in
the Company or its nominee to any of the foregoing.

6.    Maintenance of Records.  I agree to keep and maintain adequate and
current written records of all Inventions made by me (in the form of notes,
sketches, drawings and other records as may be specified by the Company),
which records shall be available to and remain the sole property of the
Company at all times.

7.    Prior Inventions.  It is understood that all Personal Inventions, if
any, whether patented or unpatented, which I made prior to my employment by
the Company, are excluded from this Agreement except as set forth on Schedule
A attached hereto. I agree to notify the Company in writing before I make any
disclosure or perform any work on behalf of the Company which appears to
threaten or conflict with proprietary rights I claim in any Personal
Invention. In the event of my failure to give such notice, I agree that I will
make no claim against the Company with respect to any such Personal Invention.

8.    Other Obligations.  I acknowledge that the Company from time to time may
have agreements with other persons or with the U.S. Government or agencies
thereof, which impose obligations or restrictions on the Company regarding
Inventions made during the course of work thereunder or regarding the
confidential nature of such work. I agree to be bound by all such obligations
and restrictions and to take all action necessary to discharge the Company's
obligations.

9.    Trade Secrets of Others.  I represent that my performance of all the
terms of this Agreement and as an employee of the Company does not and will
not breach any agreement to keep confidential proprietary information,
knowledge or data acquired by me in confidence or in trust prior to my
employment with the Company, and I will not disclose to the Company, or induce
the Company to use, any confidential or proprietary information or material
belonging to any previous employer or others. I agree not to enter into any
agreement either written or oral in conflict herewith.

10.   Modification.  I agree that any subsequent change or changes in my
employment duties, salary or compensation or, if applicable, in any Employment
Agreement between the Company and me, shall not affect the validity or scope
of this Agreement.

11.   Successors and Assigns.  This Agreement shall be binding upon my heirs,
executors, administrators or other legal representatives and is for the
benefit of the Company, its successors and assigns.

12.   Interpretation.  IT IS THE INTENT OF THE PARTIES THAT in case any one or
more of the provisions contained in this Agreement shall, for any reason, be
held to be invalid, illegal or unenforceable in any respect, such invalidity,
illegality or unenforceability shall not affect the other provisions of this
Agreement, and this Agreement shall be construed as if such invalid, illegal
or unenforceable provision had never been contained herein. MOREOVER, IT IS
THE INTENT OF THE PARTIES THAT in case any one or more of the provisions
contained in this Agreement shall for any reason be held to be excessively
broad as to duration, geographical scope, activity or subject, such provision
shall be construed by limiting and reducing it in accordance with a judgment
of a court of competent jurisdiction, so as to be enforceable to the extent
compatible with applicable law.

13.   Waivers.  If either party should waive any breach of any provision of
this Agreement, he or it shall not thereby be deemed to have waived any
preceding or succeeding breach of the same or any other provision of this
Agreement.

14.   Complete  Agreement, Amendments.  I acknowledge receipt of this
Agreement, and agree that with respect to the subject matter thereof it is my
entire agreement with the Company, superseding any previous oral or written
communications, representations, understandings, or agreements with the
Company or any officer or representative thereof. Any amendment to this
Agreement or waiver by either party of any right hereunder shall be effective
only if evidenced by a written instrument executed by the parties hereto, and,
in the case of the Company, upon written authorization of the Company's Board
of Directors.

15.   Headings.  The headings of the sections hereof are inserted for
convenience only and shall not be deemed to constitute a part hereof nor to
affect the meaning thereof.

16.   Counterparts.  This Agreement may be signed in two counterparts, each of
which shall be deemed an original and both of which shall together constitute
one agreement.

17.   Governing Law. This Agreement shall be governed and construed under
Massachusetts law.


                                       By: /s/ Carl Franzblau
                                           ------------------
                                           CARL FRANZBLAU


Accepted and Agreed:

HEMAGEN DIAGNOSTICS, INC.

                                       By: /s/ Lawrence Gilbert
                                       Title: Member of the Board of Directors
                                       Date: 5/18/99

                                 SCHEDULE A
                                 ----------

                          LIST OF PRIOR INVENTIONS

Identifying Number and/or Brief Description:

All discoveries, processes, designs, technologies and improvements relating to
hemagglutination technology.