AGREEMENT CONCERNING INVENTIONS, DISCOVERIES, IMPROVEMENTS,
                TRADE SECRETS AND OTHER CONFIDENTIAL INFORMATION

In  consideration  of  employment  by  EPITOPE,   INC.,  or  its   subsidiaries,
affiliates,  successors  or assigns  (collectively  referred to as  "Employer"),
Andrew S. Goldstein ("Employee") agrees as follows:
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1.  DISCLOSURE AND ASSIGNMENT TO EMPLOYER

Employee  will  disclose  immediately  and assign to  Employer,  or to any other
person  designated  in writing by  Employer,  all  inventions,  discoveries  and
improvements,  patentable or unpatentable,  made,  conceived or first reduced to
practice by Employee, alone or jointly with others, during his employment, which
inventions or improvements:

    A.   Were made, conceived or first reduced to practice in the performance of
         duties  assigned  to or  undertaken  by the  Employee as a part of such
         employment, or

    B.   Were made, conceived or first reduced to practice with the material use
         of the Employer's time, material, facilities or funds, or

    C.   Make use of any trade secrets or other confidential  information of the
         Employer's with which Employee comes into contact, or

    D.   Relate to any investigations or obligations undertaken by the Employer,
         the  details  of which the  Employee  became  aware of  because of this
         employment, or

    E.   Which  relate  to  investigations  or  obligations  undertaken  by  the
         Employer  and which are being  performed  at the  physical  location of
         employment, and to which the Employee has access.

All such inventions, discoveries and improvements will be the sole and exclusive
property of Employer.

2.  PERFECTION OF RIGHTS,  TITLE AND INTEREST,  AND OBTAINING OF PATENT

Employee will, during his employment for Employer and thereafter, perform at the
request and expense of Employer  all lawful acts and  execute,  acknowledge  and
deliver all  instruments  deemed  necessary  or desirable by Employer to vest in
Employer the entire right, title and interest in the inventions, discoveries and
improvements  referenced  in Section I [sic]  above,  and to enable  Employer to
properly  prepare,  file and  prosecute  applications  for and obtain and defend
patents of the United  States and of  foreign  countries,  as well as  reissues,
renewals  and  extensions  thereof,  and to  obtain  and  record  title  to such
applications and patents,  so that Employer shall be the sole and absolute owner
thereof  in any  and  all  countries  in  which  it may  desire  patent  or like
protection.

3.  NONDISCLOSURE  TO UNAUTHORIZED PERSONS

Unless  authorized or instructed in writing by Employer,  or required by legally
constituted  authority,  Employee will not,  except as required in the course of
Employer's business,  during or after his employment,  disclose to others or use
any of Employer's inventions, discoveries,  improvements or any trade secrets or
other  confidential  information,  knowledge or data which he obtains during the
course of employment related to formulae, processes,  machines, or compositions,
whether or not developed by him,  unless and until,  and then to the extent that
such items become  available to the public,  other than by his act or failure to
act.  In  addition,  the  Employee  agrees to use his best  efforts  to  prevent
accidental  or negligent  loss of such  inventions,  discoveries,  improvements,
trade secrets or other confidential  information,  knowledge or data, or release
to any person not authorized to received [sic] such items.

4.  DELIVERY OF MODELS AND OTHER MATERIALS

During or after his employment for Employer,  Employee will deliver  immediately
to  Employer  upon its  request  all models,  drawings,  maps,  plans,  reports,
memoranda,  diaries,  notes, records,  plates,  blueprints.  sketches,  letters,
manuals,  documents,  chemicals,  biological  materials and all other  writings,
graphic  records  and  materials  made or  compiled  by,  or  delivered  or made
available  to, or  otherwise  obtained  by him,  containing  or  relating to any
inventions,  discoveries  and  improvements  which the  Employee  is required to
disclose  under this  agreement,  or with respect to any other trade  secrets or
other confidential  information,  knowledge or data designated by Employer which
Employee has obtained as the result of his  employment.  Employee will retain no
excerpts, notes, photographs, reproductions or copies of any such material.

5.  LIST OF INVENTIONS NOT SUBJECT TO THIS AGREEMENT

Employee attaches as Exhibit A to this agreement,  a list and description of all
unpatented  inventions  (including  those  for  which  patent  applications  are
pending),  which he has made,  conceived or first  reduced to practice  prior to
this employment by Employer. Exhibit A includes, and is limited to, all

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those inventions,  discoveries and improvements that Employee later may claim to
be excluded from this agreement.  Such inventions,  discoveries and improvements
shall be  excluded  from this  agreement,  unless  further  made or  reduced  to
practice in one of the manners  specified  in Section I [sic]  above.  Such list
shall be updated by Employee from time to time to include all  inventions  made,
conceived or first reduced to practice  during  Employee's  employment,  but not
falling within the scope of this agreement. Employer will not disclose to others
or use any information,  knowledge or data that it derives from Exhibit A, until
and unless,  and then to the extent  that such  information,  knowledge  or data
becomes available to the public, other than by Employer's act or failure to act.

6.  OTHER LEGAL RIGHTS OF EMPLOYER

The rights and duties of  Employer  and  Employee  under this  agreement  are in
addition to, and not in lieu of, those rights and duties afforded to and imposed
upon them by law, or at equity.  Employer and  Employee  agree to the entry of a
temporary  restraining order and permanent  injunction by any court of competent
jurisdiction to prevent breach or further breach of this agreement.  Such remedy
shall be in addition to any other  remedy  available to the Employer or Employee
at law, or at equity.

7.  SEVERABILITY  OF PROVISIONS

The provisions of this agreement are severable,  and if any provision  hereof is
held invalid or  unenforceable  the remaining  provision of this agreement shall
not be affected thereby.

8.  SUCCESSORS, HEIRS, ASSIGNEES OR NOMINEES

This agreement shall inure to the benefit of and be binding upon Employer,  its
successors,  assigns or nominees and also upon Employee,  his estate, heirs and
assigns.

9.  WAIVER

No  provision  of this  agreement  may be waived by  either  party,  except by a
writing  signed by that party.  The waiver of any portion of this agreement with
respect to any person or  invention  shall be construed  narrowly  and shall not
affect the right of the party granting the waiver to enforce any other provision
of this  agreement or to enforce any provision of this agreement with respect to
any other  person or  invention.

10. REFERENCE  TO GENDER

Any reference in this agreement to the masculine gender shall also be deemed to
refer to the feminine gender.

11. OREGON LAW TO BE APPLIED

The interpretation of and performance under this agreement shall be governed by
the laws of the State of Oregon.

                            NOTICE TO EMPLOYEE

THIS AGREEMENT MAY REQUIRE TRANSFER TO YOUR EMPLOYER OF CERTAIN INVENTIONS.  YOU
MAY WISH TO CONSULT  YOUR LEGAL  COUNSEL FOR ADVICE  CONCERNING  YOUR RIGHTS AND
OBLIGATIONS.

            DATED the 28 day of April, 1988

                                 /s/ Andrew S. Goldstein
                                 -----------------------------------
                                 EMPLOYEE


                                 -----------------------------------
                                 EPITOPE, INC.

   /s/ Shirley McKenna
-----------------------------
WITNESS

ADDRESS:

         EPITOPE, INC.
-----------------------------
    15425-E S.W.KOLL PARKWAY
      BEAVERTON, OR  97006
-----------------------------

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                                    EXHIBIT A

A list and description of inventions,  discoveries and improvements  (including
those for which patent  applications are pending) specified in Section 5 of this
agreement. List updated through                                     .
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