Exhibit 10.32


                                 PROMISSORY NOTE


$296,000                                                  Stratford, Connecticut
                                                                 October 4, 1995


     FOR VALUE RECEIVED, the undersigned, G.S. BECKWITH GILBERT ("Mr. Gilbert"),
hereby  promises  to pay to the  order  of  DIANON  SYSTEMS,  INC.,  a  Delaware
corporation or its successors (the  "Holder"),  the principal sum of Two Hundred
Ninety-Six  Thousand DOLLARS ($296,000) or such lesser amount as may then be the
unpaid principal balance hereof (the "Principal Amount"), together with interest
thereon,  payable on October 4, 1997 by certified or official bank check or wire
transfer of immediately available funds to an account designated by the Holder.

     Mr.  Gilbert  promises  to pay  interest  on the  Principal  Amount of this
promissory  note (this "Note") from the date hereof until such Principal  Amount
is paid in full at the fixed  rate of 7% per  annum,  such  interest  payable in
arrears on October 4, 1997; provided,  however, that any Principal Amount hereof
not paid when due and, to the fullest  extent  permitted by applicable  law, any
overdue interest shall bear interest at a rate per annum equal to 10% (after, as
well as before, any judgment),  payable on demand.  Interest shall be calculated
on the basis of a 360-day year for the actual number of days elapsed.

     This Note is issued in connection with the transactions contemplated by the
Stock  and  Warrant  Purchase  Agreement,  dated  as of  October  4,  1995  (the
"Agreement")  among the Gilbert  Family Trust (the "Trust"),  the G.S.  Beckwith
Gilbert I.R.A. Contributory Account (the "IRA"), Mr. Gilbert and the Holder, and
the Warrants  issued by the Holder in connection  therewith and  represented  by
Warrant Certificate No. W-1 (the "W-1 Warrants").  Except as otherwise indicated
herein capitalized terms used in this Note are defined in the Agreement.

     This  Principal  Amount due under this Note and the date on which  interest
payments are due are subject to adjustment  in accordance  with the terms of the
second paragraph of Section 1 of the W-1 Warrants.

     This Note shall be binding upon Mr.  Gilbert and his  successors  and shall
inure to the benefit of Mr. Gilbert and his successors.

     Mr.  Gilbert hereby waives  presentment,  demand,  notice,  protest and all
other  demands  and  notices  in  connection  with  the  delivery,   acceptance,
performance or enforcement of this Note.

     The provisions of this Note may be amended, modified, changed or terminated
only be an agreement in writing signed by Mr. Gilbert and the Holder.

     If at any time the indebtedness evidenced by this Note is collected through
legal  proceedings  or  this  Note is  placed  in the  hands  of  attorneys  for
collection,  Mr.  Gilbert  and each  endorser  of this Note  hereby  jointly and
severally  agree to pay all  costs  and  expenses  (including  attorneys'  fees)
incurred by the Holder in collecting or attempting to collect such indebtedness.

     If any  payment on this Note  becomes due and payable on a day other than a
Business Day (as hereinafter defined), the maturity thereof shall be extended to
the  immediately  following  Business Day and interest  shall continue to accrue
during  such  extension.  "Business  Day" means any day other than a Saturday or
Sunday  or any  other day on which  commercial  banks in New York,  New York are
authorized or obligated by law to close.

     This Note is non-transferrable.




     THE BORROWER HEREBY  KNOWINGLY,  VOLUNTARILY AND  INTENTIONALLY  WAIVES ANY
RIGHT HE MAY HAVE TO A TRIAL BY JURY OF ANY DISPUTE ARISING UNDER OR RELATING TO
THIS  NOTE  AND  AGREES  THAT ANY SUCH  DISPUTES  SHALL BE TRIED  BEFORE A JUDGE
SITTING WITHOUT A JURY.

     THIS NOTE IS GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH,
THE LAWS OF  CONNECTICUT  WITHOUT  REGARD  TO THE  CONFLICT  OF LAWS  PROVISIONS
THEREOF.


                                          /s/ G. S. Beckwith Gilbert
                                          --------------------------
                                          G. S. Beckwith Gilbert