Exhibit 10.25

                              EMPLOYMENT AGREEMENT

         This AGREEMENT made effective November 18, 1996 between DIANON SYSTEMS,
INC., a Connecticut corporation, and any successor thereto, hereinafter referred
to as the "Company," and STEVEN CLAYTON, residing in Naperville, Illinois.

                                   WITNESSETH:

         WHEREAS,  the Company wishes to employ STEVEN CLAYTON as Vice President
Information  Services of the Company  and STEVEN  CLAYTON  wishes to accept such
employment,  in each case on the terms and subject to the  conditions  set forth
below; and

         WHEREAS,  the services that STEVEN CLAYTON  should render  hereunder to
the Company are unique and valuable; and

         WHEREAS,  the  parties  desire to reduce  the terms and  conditions  of
STEVEN CLAYTON's employment to writing;

         NOW,  THEREFORE,  in  consideration of the terms and conditions and the
mutual  covenants  contained in this  Agreement,  the Company and STEVEN CLAYTON
hereby agree as follows:

         1.       Employment

         The Company  hereby  employs  STEVEN  CLAYTON and STEVEN CLAYTON hereby
accepts such employment upon the terms and conditions hereinafter set forth. The
parties acknowledge that STEVEN CLAYTON's employment with the Company is at will
and terminable by either party at any time for any reason.

         2.       Duties and Responsibilities

         STEVEN CLAYTON shall perform with continuous diligence those activities
assigned to STEVEN CLAYTON by the Company's  Senior Vice  President  Finance and
Chief Financial Officer,  President and Chief Operating Officer, Chief Executive
Officer  and/or  Board  of  Directors  from  time to time,  initially  including
responsibility  for Information  Services;  keeping full and complete records of
all business  and/or  research  activities in which STEVEN  CLAYTON  engages and
surrendering all such records and materials on request; improving strategies for
achieving the Company's goals; motivating co-worker performance; keeping abreast
of all new  developments  in STEVEN  CLAYTON's area of expertise;  participating
actively in research and business meetings; and abiding by all Company policies.

         3.       Salary and Incentive Compensation

         The Company shall compensate STEVEN CLAYTON for his services during the
term of this  Agreement  on a  salaried  basis  paid in  installments  at a rate
determined  by the Company  from time to time,  provided  that the initial  base
salary shall be at an  annualized  rate of $120,000.  STEVEN  CLAYTON shall also
participate,  according to its terms, in any management  incentive  compensation
program maintained by the Company for salaried Grade 17 management  employees of
the Company during the term of this Agreement.

         4.       Relocation, Travel Expenses and Temporary Housing

         The  Company  shall  provide  STEVEN  CLAYTON  relocation  expenses  in
accordance  with  the  terms  of  its  established  relocation  policy  for  his
relocation from Illinois to Connecticut in connection  with the  commencement of
his employment with the Company. The Company shall pay STEVEN CLAYTON reasonable
costs associated with temporary  housing,  including car rental, for up to three
months in connection with such  relocation.  The Company shall also pay air fare
for up to twelve round-trips  between Connecticut and Chicago in connection with
such relocation.




         5.       Signing Bonus

         The Company  shall pay STEVEN  CLAYTON a signing  bonus of $14,000 less
applicable  tax  deductions  within a  reasonable  time after he  commences  his
employment with the Company.

         6.       Fringe Benefits

         During the term of this  Agreement,  the Company shall  provide  STEVEN
CLAYTON  benefits and  emoluments as authorized  for all other salaried Grade 17
management employees of the Company as they may be modified from time to time by
the  Company  during  the  term  of this  Agreement,  including  at the  time of
execution of this Agreement,  health and medical insurance, life insurance, sick
leave, vacation, holidays, retirement plan participation and stock purchase plan
participation..

         7.       Stock Options

         On the first day of  STEVEN  CLAYTON's  active  employment  under  this
Agreement,  the Company  shall award him  options to purchase  15,000  shares of
common  stock of the Company at the fair market  value on said date,  subject to
the terms,  conditions,  vesting schedules and expiration dates described in the
incentive stock option award document attached to this Agreement as Exhibit A.

         8.       Company Property

         At the  time his  employment  with the  Company  terminates,  or at any
earlier  point in time when a request is made by the  Company  for same,  STEVEN
CLAYTON  will turn over to the Company  all notes,  reports,  memoranda,  books,
records,  chemicals,  devices and  documents,  whether in written,  typewritten,
computerized  or any other form,  which are in STEVEN  CLAYTON's  possession  or
under his control,  whether prepared by him or others, related to the Company or
relating to the business of the Company.

         9.       Proprietary Information

         STEVEN  CLAYTON  hereby  agrees to all the terms and  conditions of the
Company's Employee Proprietary  Information Agreement attached hereto as Exhibit
B and incorporated herein and has executed a copy thereof concurrently with this
Agreement.

         10.      Non Competition

         STEVEN CLAYTON agrees that, to the fullest extent permitted by law, for
the period of one (1) year after his  termination  date STEVEN  CLAYTON (a) will
not solicit business on behalf of any entity in the clinical chemistry business,
which is  performing  or marketing  anatomical  pathology  services  ("Competing
Entity"),  (b) will not solicit business from customers of the Company, (c) will
not solicit the  employment  or services of any of the  employees of the Company
and  (d)  will  not,  directly  or  indirectly,  participate  in the  ownership,
management,  operation  or control of any  Competing  Entity in the  continental
United  States  other than  California,  Washington  and Oregon,  provided  that
nothing in this Paragraph shall prevent investment  ownership of less than 5% of
the shares of any publicly traded Competing Entity.

         11.      Remedy for Breach

         STEVEN CLAYTON acknowledges:

                  (a)      that he may be a director  and officer of the Company
                           and as such he would  be  conversant  with,  and have
                           access  to,  the  business  affairs,  records,  trade
                           secrets,  customers  and customer  lists,  suppliers,
                           supplier   lists,   patents,    technical   know-how,
                           chemicals,  devices, sales or distribution agents and
                           representatives,  sales or  distribution  agents  and
                           representatives'  lists,  and other  confidential and
                           proprietary information of the Company;




                  (b)      that his compliance with the covenants and agreements
                           in  this   Agreement  is  necessary  to  protect  the
                           goodwill  and  other  proprietary   interest  of  the
                           Company; and

                  (c)      that a breach of his covenants and agreements in this
                           Agreement will result in continuing  and  irreparable
                           damage  to the  Company  for which  there  will be no
                           adequate remedy at law.

         Both the parties  recognize that the services to be rendered under this
Agreement  by STEVEN  CLAYTON  are  special  and unique and of an  extraordinary
character,  and that in the event  there is a breach by  STEVEN  CLAYTON  of the
terms and  conditions of this Agreement to be performed by him, then the Company
shall be entitled,  if it so elects,  to institute and prosecute  proceedings in
any  court of  competent  jurisdiction  either  in law or in  equity,  to obtain
damages for any breach of this Agreement, or to enforce the specific performance
thereof by STEVEN CLAYTON,  or to enjoin STEVEN CLAYTON from performing services
for any Competing Entity.

         12.      STEVEN CLAYTON'S Representation

         STEVEN CLAYTON  warrants and represents  that neither the execution and
delivery nor the  performance  of this Agreement by him will in any way violate,
or conflict  with,  any other  agreement by which he may be bound or any duty or
obligation to which he may be subject and that he will take all steps  necessary
to comply with the representation.

         13.      Assignments

         The rights and obligations of STEVEN CLAYTON under this Agreement shall
be  assignable  to and binding  upon the  successors  and assigns of the Company
including any  corporation  organized by the Company to carry on the business of
the Company.

         14.      Entire Agreement

         This instrument  contains the entire  Agreement of the parties.  It may
not be changed  orally,  but only by  agreement  in writing  signed by the party
against  whom  enforcement  of any waiver,  change,  modification,  extension or
discharge is sought.  This  Agreement  supersedes  any verbal,  written or other
agreement(s) or understanding(s) existing between STEVEN CLAYTON and the Company
relating to his employment or the other matters covered herein.

         15.      Severability

         If any  provision  of  this  Agreement  shall  be  held  invalid,  such
invalidity  shall not affect any other  provisions of this Agreement not held so
invalid,  and only such provisions shall to the full extent  consistent with the
law remain in full force and effect.




         16.      Applicable Law

         This  Agreement  shall  be  governed  by  the  laws  of  the  State  of
Connecticut.

         IN WITNESS WHEREOF,  the parties have executed or caused to be executed
this Agreement.


                                    DIANON   SYSTEMS INC.



12/8/96                             BY: /s/David R. Schreiber
- -------------------                     --------------------------------
Date                                    David R. Schreiber
                                        Chief Financial Officer and
                                        Senior Vice President, Finance




12/11/96                            BY: /s/Steven Clayton
- -------------------                     --------------------------------
Date                                    Steven Clayton





                                                                       Exhibit A

                              DIANON SYSTEMS, INC.
                              200 Watson Boulevard
                          Stratford, Connecticut 06497

                                                        SO Grant No.

                               STOCK OPTION GRANT


Optionee:                     Steve Clayton    Date of Grant:  November 18, 1996

Termination Date:         November 17, 2006    Total No. of Shares:       15,000

Exercise Price Per Share             $7.875


We are  pleased to inform you that the  Compensation  Committee  of the Board of
Directors of DIANON  Systems,  Inc.  (the  "Company"),  has today granted you an
option  pursuant to the  Company's  1991 Stock  Incentive  Plan (the  "Plan") to
purchase an  aggregate  number of shares  shown above of the Common Stock of the
Company on the following terms and conditions:

         1. The purchase  price per share of the shares of Common Stock  subject
to this option is $6.625 per share.

         2. This option  shall  expire at the close of business on November  17,
2006. Subject to acceleration in the event of a Change of Control (as defined in
the Plan), you must remain in the employ of the Company or a Related Company (as
defined in the Plan) for two years from the date hereof  before you can exercise
any part of this  option.  Thereafter  this option will  become  exercisable  in
installments as follows:



          Percentage of Shares              Date of Earliest Exercise(Vesting)
          --------------------              ----------------------------------

                                                         
                  40%                                       11/18/98
                  20%                                       11/18/99
                  20%                                       11/18/00
                  20%                                       11/18/01


         In the event of a Change of Control  this  option  shall  become  fully
exercisable and vested.

         3. This option is intended to qualify as an  "Incentive  Stock  Option"
within the provisions of Section 422 of the Internal Revenue Code.

         4. The option  price shall be payable by you at the time this option is
exercised,  (i) in cash or (ii) by  delivering  shares  of  Common  Stock of the
Company which you have owned for at least six months prior to such exercise,  or
a combination  of cash and such shares,  having an aggregate  value equal to the
aggregate  option  price of the  shares as to which  this  option  is  exercised
(basing the value of any such shares of Common Stock on the fair market value of
the Common  Stock on the date of  exercise).  No shares of Common Stock shall be
issued pursuant to exercise of this option until full payment  therefor has been
made.

         5. This option may be exercised  only by you and may not be transferred
except by will or the laws of  descent  and  distribution.  In the event of your
death, your legal  representatives  may exercise this option as to the shares of
Common  Stock which were  immediately  purchasable  by you at the date of death,
within ninety (90) days  following the date of death (but in no event later than
November 17, 2006).




         6. If your employment with the Company  terminates  after reaching your
normal  retirement  date under the Company's  retirement  plan or for any reason
beyond your  control  other than your death,  your  option  privileges  shall be
limited to the shares of Common Stock which were immediately  purchasable by you
at the date of such  termination and such option  privileges shall expire unless
exercised  within ninety (90 days) days after the date of such  termination  and
prior to the close of business on  November  17,  2006.  If your  employment  is
terminated for reasons within your control, including without limitation,  cause
and voluntary resignation, all rights under this option shall expire on the date
of such termination.

         7. Your option is granted in tandem with a Limited  Stock  Appreciation
Right ("LSAR") which may be exercised only within the 60-day period  following a
Change of Control (as defined in the Plan). This means that with respect to each
share under  option,  you may  exercise  either the option or the Limited  Stock
Appreciation   Right,   but  not  both.  Upon  exercise  of  the  Limited  Stock
Appreciation Right, you shall receive,  for each share with respect to which the
Limited Stock Appreciation  Right is exercised,  an amount equal in value to (I)
the fair market  value of a share of Common  Stock on the date of exercise  over
(ii) the exercise price of the related  option.  The Limited Stock  Appreciation
Right shall be payable solely in cash.  Such amount shall be paid within 30 days
of the exercise of the Limited Stock Appreciation Right.

         8. The  Company  has the right to delay the  exercise of your option if
listing  registration or qualification of the Common Stock is required under any
federal or state  securities  law or stock  exchange or similar rule and has not
been obtained.

         9.  Nothing  herein  shall  restrict  the right of the  Company  or any
Related Company to terminate your employment at any time, with or without cause,
or to withhold  required  amounts upon the exercise of your option or LSAR.  The
Company  shall have the right to require you to pay, or make other  arrangements
satisfactory  to the Committee to satisfy,  all tax  withholding  obligations in
connection with the exercise of your option or LSAR.

         10. This option is subject to all of the other  terms,  provisions  and
conditions  of the  Plan,  a copy of which has been  furnished  to you and other
copies of which may be obtained by you from the Company.

                                              Very truly yours,

                                              DIANON Systems, Inc.



                                              By:   /s/Kevin C. Johnson
                                                  -------------------------
                                                    Kevin C. Johnson
                                                    President



Date:        12/11/96
     -------------------------

     /s/Steven Clayton
- ------------------------------
(Signature)

     1439 Keats Ave.
- ------------------------------
(Address)

      Naperville, IL  60564
- ------------------------------




                                                                       Exhibit B

                                    AGREEMENT

         THIS AGREEMENT, made this 12/11/96 by and between DIANON SYSTEMS, INC.,
its  affiliates,  subsidiaries,  successors  and  assigns  (collectively  called
hereinafter  "DIANON") and Steven Clayton,  an individual residing at 1439 Keats
Avenue, Naperville, Illinois 60564 (hereinafter called "Employee").

         In  consideration  of the  commencement  of Employee's  employment with
DIANON, the payment of compensation and benefits for such employment, and access
to sensitive information,  Employee and DIANON acknowledge,  represent and agree
to the terms and conditions set forth in this Agreement.

         1.  Employee's  employment  with DIANON creates a relationship of trust
and  confidence  between the parties.  Employee  agrees  that,  during and after
his/her  employment  with DIANON,  Employee  will not use or disclose,  or allow
anyone else to use or disclose,  any  confidential  information  relating to the
products, sales and/or business affairs of DIANON or of any customer or supplier
of DIANON,  or any  information  created,  discovered,  or  developed  by or for
DIANON, or acquired by DIANON,  that has commercial value in DIANON's present or
future business ("Confidential Information"),  except as may be necessary in the
performance  of  Employee's  employment  with DIANON or as may be  authorized in
advance by  appropriate  officials of DIANON.  By way of  illustration,  but not
limitation,   Confidential  Information  includes  processes,   formulas,  data,
know-how, inventions,  improvements,  techniques, marketing plans, product plan,
strategies,  forecasts,  customer lists and any other  information  Employee has
reason to know  DIANON  would  like to treat as  confidential  for any  purpose.
Employee  agrees to keep  Confidential  Information  secret  whether  or not any
document containing such information is marked confidential.

         2. All rights, title and interest in all records,  documents,  or files
concerning the business of DIANON,  including,  but not limited to biomaterials,
processes,  letters,  trade  secrets,  laboratory  notebooks or other written or
electronically recorded material, whether or not produced by the Employee, shall
be and remain the  property  of DIANON.  Upon  termination  of  employment,  the
Employee shall not have the right to remove any such records from the offices of
DIANON. In addition,  Employee agrees to promptly return to DIANON all things of
whatsoever  nature that belong to DIANON,  and all records (in whatsoever  form,
format or medium) contained or related to Confidential Information of DIANON.

         3. Employee agrees to assign,  and does hereby assign to DIANON, all of
his/her  right,  title  and  interest  in and to all  inventions,  improvements,
discoveries or technical developments,  whether or not patentable,  which he/she
solely or jointly  with others,  may  conceive or reduce to practice  during the
term of his/her  employment (a) which are related in whole or in part,  directly
or indirectly,  to DIANON's product line, research and development,  or field of
technological or industrial specialization,  or (b) in the course of utilization
by DIANON of Employee's services in a technical or professional  capacity in the
areas  of  research,   development,   marketing,   management,   engineering  or
manufacturing,  or (c)  pursuant  to any  project of which  Employee is or was a
participant or member that is or was either  financed or directed by DIANON,  or
(d) at DIANON's expense, in whole or in part.

         4. Employee  agrees to disclose  promptly to DIANON's  President or his
designee, all ideas,  discoveries,  and improvements conceived by Employee alone
or in collaboration with others, and to cooperate fully with DIANON, both during
and after  employment,  with  respect  to the  procurement  of  patents  for the
establishment and maintenance of DIANON's or its designee's rights and interests
in said invention,  improvement,  discoveries or  developments,  and to sign all
papers which DIANON may deem  necessary or desirable  for the purpose of vesting
DIANON or its  designees  with such rights,  the expenses  thereof to be paid by
DIANON.

         5. The Employee  shall,  while employed by DIANON,  devote his/her best
efforts and his/her full time to the business of DIANON.




         6. In the event of a breach or threatened  breach of the  provisions in
this  Agreement,  DIANON  shall be entitled to an  injunction  restraining  such
breach,  it being  recognized  that any injury  arising  from a breach  would be
irreparable  and could have no adequate  remedy at law; but nothing herein shall
be construed as prohibiting  DIANON from pursuing any other remedy available for
such  breach or  threatened  breach.  In the event  that  Employee  breaches  or
threatens  a breach of this  Agreement,  DIANON  shall be  entitled  to have its
reasonable  legal fees and costs  paid by the  Employee  for any legal  services
relating to the breach or threatened breach.

         7. This  Agreement is not intended,  and should not be construed in any
way, as a contract of  employment  for a definite  period of time or to limit or
restrain   DIANON's  or  the  Employee's   right  to  terminate  the  employment
relationship at any time.

         8. In the  event  any  provision  or  paragraph  of this  Agreement  is
declared to be invalid or unenfoceable, then the balance of this Agreement shall
remain in full force and effect.

         9. This  Agreement  shall be construed and enforced in accordance  with
the laws of the State of Connecticut.

         10. The  foregoing  contains the entire  Agreement  between the parties
pertaining to confidential  DIANON  documents and  information.  No modification
thereof shall be binding upon the parties unless the same is in a writing signed
by the  respective  parties.  This Agreement and all of the terms and conditions
contained  herein  shall  remain in full force  during the period of  employment
notwithstanding any changes in compensation.

         11.  Employee   represents  and  warrants  that  he/she  has  no  other
agreements or  commitments  that would hinder or prevent  performance of his/her
job  responsibilities  with DIANON.  Unless authorized to do so, Employee agrees
not to disclose to DIANON or use in his/her employment with DIANON any invention
or  confidential  information  belonging to any former  employer or to any other
person other than DIANON.

         IN WITNESS WHEREOF,  the parties have entered into this Agreement as of
the date set forth below.

Employee:                                 DIANON SYSTEMS, INC.


     /s/Steven Clayton                    By:       /s/David R. Schreiber
- ------------------------                     ---------------------------------
Steven Clayton                                  David R. Schreiber

Dated:      12/11/96
      ------------------------