Exhibit 10.26
                              SEPARATION AGREEMENT


         WHEREAS, DANIEL J. CRONIN III and DIANON SYSTEMS, INC. ("Company") wish
to end the employment  relationship between them and wish to resolve any and all
claims, disputes or causes of action that do or may exist between them;

         NOW  THEREFORE,  in  consideration  of the mutual  covenants  and other
valuable  considerations  contained herein, the Company and DANIEL J. CRONIN III
agree as follows:

         1.  DANIEL J.  CRONIN III  resigns  his  full-time  employment  and his
officer position with the Company effective as of December 6, 1996.

         2. The Company  shall pay DANIEL J. CRONIN III  separation  pay, at his
last rate of base salary subject to applicable  deductions,  for the period four
months  after his  termination  and for so much of the  following  two months as
DANIEL  J.  CRONIN  III has  not  obtained  other  employment  (the  "Separation
Period").  This  separation pay shall be paid in equal  installments  on regular
payroll dates of the Company throughout the Separation Period.

         3. Throughout the Separation  Period,  the Company shall  contribute to
medical coverage for DANIEL J. CRONIN III and his dependents at the same rate it
contributes for active  employees,  provided DANIEL J. CRONIN III and his family
are eligible and elect continuation coverage.

         4. The  Company  shall pay DANIEL J. CRONIN III the bonus he would have
received  under  the  Company's  1996  Management   Incentive  Program  had  his
employment  continued  through the date on which payments under said program are
made.  The  Company  commits  that not less than 70% shall be used for DANIEL J.
CRONIN's individual goals achievement in the calculation of said bonus under the
program's formula.  This payment will be made at the same time payments to other
Management Incentive Program participants are made.

         5. The Company  shall make a  contribution  to DANIEL J.  CRONIN  III's
401(k) plan account for the year 1996.

         6. The Company shall respond to inquiries about DANIEL J. CRONIN III by
prospective  employers by disclosing  only his salary,  date of  employment  and
title.

         7. DANIEL J. CRONIN III acknowledges  his continuing  obligation not to
use or divulge  confidential  Company  documents and information to which he has
had access in the course of his  employment  with the Company.  DANIEL J. CRONIN
III  agrees  that he shall  return to the  Company  and retain no copies of, any
Company  information,  documents  and/or equipment in his possession at the time
his employment with the Company terminates.

         8. DANIEL J. CRONIN III, agrees to make himself reasonably available to
consult with the Company on Information Systems matters up to six days per month
during the Separation  Period.  The Company agrees to reimburse DANIEL J. CRONIN
III for any  reasonable  travel  expenses  he  incurs in order to  fulfill  this
obligation.

         9.  DANIEL  J.  CRONIN  III,  on  behalf  of  himself,  his  executors,
administrators  and assigns,  hereby releases the Company,  its affiliates,  and
their  respective  directors,   officers,  agents,  employees,   benefit  plans,
fiduciaries and  administrators  of such benefit plans and their  successors and
assigns  (hereinafter  "Released  Company  Parties")  from any and all claims or
causes  of  action  of any kind  arising  on or  before  the date he signs  this
Agreement,  other than vested rights under benefit plans, which DANIEL J. CRONIN
III has, had or may have against any of them,  whether or not now known  arising
from DANIEL J. CRONIN III's  recruitment  for employment  with the Company,  his
employment  or officer  position  with the Company,  or the  termination  of his
employment and officer position with the Company,  including without  limitation
any claims under the Age Discrimination in Employment Act.




         10.  DANIEL J. CRONIN III on behalf of himself,  his heirs,  executors,
administrators  and assigns,  further  agrees never  directly or  indirectly  to
commence or prosecute, or to permit or advise to be commenced or prosecuted, any
action,  proceeding,  or charge against any Released Company Party, in any state
or federal  court,  administrative  agency or arbitral forum with respect to any
matter whether or not now known, for any claim based upon any act,  transaction,
practice,  conduct,  or omission that  occurred  prior to the date he signs this
Agreement,  including but not limited to, rights under the Age Discrimination in
Employment Act or any other federal, state, or local laws prohibiting age, race,
sex, national origin,  religion,  or other forms of  discrimination,  claims for
breach of contract or promissory estoppel or tort, and claims growing out of any
legal restrictions on the Company's right to terminate its employees or officers
which he now has,  or claims to have,  or which at any time  heretofore  had, or
which at any time hereafter may have.

         11. The parties  recognize and agree that this  Agreement  does not and
shall not  constitute  an admission of liability or  wrongdoing  by any Released
Company Party.

         12. The parties agree that, except as necessary to comply and to obtain
compliance with this Agreement,  or to comply with any federal,  state, or local
law, they will not disclose the terms of this Agreement.

         13.  In the event  DANIEL  J.  CRONIN  III  files a claim,  lawsuit  or
complaint against any Released Company Party in any court or governmental agency
with  respect to the claims he has  released  under  this  Agreement,  DANIEL J.
CRONIN  III shall be liable for all costs and  expenses  including  legal  fees,
incurred by any Released Company Party in defense of that action.

         14.  DANIEL J. CRONIN III  represents  that he has  carefully  read and
completely  understands  this  Agreement  and  that  he has  entered  into  this
Agreement  voluntarily after having had an opportunity to consult with his legal
advisors.

         15. DANIEL J. CRONIN III acknowledges that the commitments, waivers and
releases he gives in this  Agreement are in exchange for valuable  consideration
to which he is not otherwise  entitled,  and which constitutes a full accord and
satisfaction of any claims he may have against any Released Company Party.

         16. DANIEL J. CRONIN  acknowledges  that he has been given a reasonable
time to review the waivers and  releases  contained in this  Agreement  prior to
signing it.

         17. This Agreement  constitutes the entire  Agreement of the parties on
the  subject  matter  hereof  and  supersedes  any  and  all  prior  agreements,
understandings or commitments, oral or written.

         18. This Agreement shall be governed by applicable  Federal law and the
laws of the State of Connecticut.



                                    DANIEL J. CRONIN III


   12/24/96                             /s/Daniel J. Cronin III
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Dated                               Signature

                                    DIANON SYSTEMS, INC.


    12/23/96                             /s/Kevin C. Johnson
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Dated                               By:  Kevin C. Johnson, President