EXHIBIT 10.2


                        REGISTRATION RIGHTS AGREEMENT


            THIS REGISTRATION  RIGHTS  AGREEMENT,  dated as of May 1, 1999 (this
"Agreement"),  is by and between DIANON  SYSTEMS,  INC., a Delaware  corporation
(the  "Company"),  and KYTO  MERIDIEN  DIAGNOSTICS,  L.L.C.,  a New York limited
liability company ("KMD").


            WHEREAS,  pursuant to that certain Asset Purchase Agreement dated as
of April 7, 1999 by and among the Company, KMD, Kyto Diagnostics, L.P., Meridien
Diagnostics  Labs,  Inc.,  A. Bruce  Shapiro and Ralph M.  Richart,  on the date
hereof,  KMD became the owner of 300,000  shares of the Company's  common stock,
par value $.01 per share (the "Shares");


            WHEREAS,  the Shares have not been  registered  under the Securities
Act (as hereinafter  defined) or any state securities laws, and the certificates
representing the Shares bear a legend restricting their transfer; and


            WHEREAS,  in connection with the foregoing,  the Company has agreed,
subject to the terms, conditions and limitations set forth in this Agreement, to
provide KMD and its successors, assigns and transferees as permitted herein with
certain registration rights in respect of the Shares.


            NOW,  THEREFORE,  in  consideration  of  the  mutual  covenants  and
promises contained herein, the parties hereto agree as follows:


DEFINITIONS

            1.1  Definitions.   Capitalized  words  and  phrases  used  and  not
otherwise defined in this Agreement shall have the following meanings:

            "Commission"  means the  Securities  and Exchange  Commission or any
other federal agency at the time administering the Securities Act.

            "Common Stock" means the common stock,  par value $.01 per share, of
the Company (including, without limitation, the Shares) and all shares hereafter
authorized  of any class of common stock of the  Company,  and, in the case of a
reclassification,  recapitalization or other similar change in such Common Stock
or in the case of a consolidation  or merger of the Company with or into another
Person,  such  consideration  to which a holder of a share of Common Stock would
have been entitled upon the occurrence of such event.

            "Company"  includes,  in addition to the Company,  any  successor or
assignee corporation or corporations into which or with which the Company may be
merged or consolidated, any corporation for whose shares the Common Stock may be
exchanged  and any assignee of or successor to all or  substantially  all of the
assets of the Company.




            "Exchange  Act"  means the  Securities  Exchange  Act of 1934,  as
amended.

            "Holder" means KMD, and each Person who is a Permitted  Transferee
of KMD.

            "NASDAQ"  means The  Nasdaq  Stock  Market's  Automated  Quotation
System--National Market.

            "Permitted Transferee" means any corporation,  partnership,  limited
liability  company or other Person  controlled  by,  controlling or under common
control with KMD to which KMD has  Transferred the Shares.  Notwithstanding  any
Person's  status  as  a  Permitted  Transferee,   any  Transfer  of  Registrable
Securities shall be subject to the provisions of Section 8.1.

            "Person" means any individual,  corporation,  partnership,  trust or
other entity of any nature whatsoever.

            "Register," "registered," and "registration," when used with respect
to the capital stock of the Company,  means a registration effected by preparing
and filing a registration  statement or similar  document in compliance with the
Securities Act with the Commission which has been declared or ordered  effective
by the Commission in accordance with the Securities Act.

            "Registrable  Securities"  means the Shares  (and shall  include all
shares of Common Stock received by the Holder in respect  thereof  pursuant to a
stock split, stock dividend or other recapitalization of the Company or pursuant
to any merger,  consolidation  or  reorganization  involving the  Company).  The
Shares  shall  cease  to be  Registrable  Securities  when  (i)  a  registration
statement  with  respect  to the sale of all of the  Shares  shall  have  become
effective  under the  Securities  Act and the Shares shall have been disposed of
pursuant to such registration statement, (ii) the Shares shall have been sold or
otherwise  distributed  pursuant to Rule 144 (or any successor  provision) under
the Securities Act in accordance with the volume and other limitations  thereof,
or (iii) the Shares shall have ceased to be outstanding.

            "Securities  Act" means the Securities Act of 1933, as amended,  and
the rules and regulations of the Commission promulgated thereunder.

            "Transfer" means any transfer, sale, gift, assignment, distribution,
conveyance, pledge, hypothecation, encumbrance or other voluntary or involuntary
transfer of title or beneficial interest,  whether or not for value,  including,
without  limitation,  any  disposition  by  operation  of law or any  grant of a
derivative or economic interest therein.


PIGGYBACK REGISTRATION

      1.2 Notice of Registration.  (a) If at any time after the date hereof, the
Company  proposes  to  register  any of its  Common  Stock,  either  for its own
account,  or for the  account  of any  Person  other  than the  Holder,  but not
including (i) a  registration  relating to employee  stock  option,  purchase or
other  employer  plans  or (ii) a  registration  on Form  S-4 or Form S-8 or any
successor form thereto (a "Piggyback Registration"), the Company will:


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                  (X) promptly give written  notice  thereof to the Holder prior
to the proposed date of filing; and

                  (Y)  use  its  best  efforts  to  include  in  such  Piggyback
Registration  and  in  any  underwriting  involved  therein  up to  all  of  the
Registrable  Securities  which the Holder  requests in writing to be so included
within 30 days after receipt of such written  notice from the Company,  provided
that the  Company  may  request  the  Holder to enter into such  agreements  and
documents as are customary in the securities business for an arrangement between
an underwriter and a company of the Company's size and investment stature and as
are reasonably requested to evidence the commitment of the Holder to participate
in  the   registration,   including   customary   custody  and   indemnification
arrangements. 

           (b) The Holder shall have the right to exercise its right pursuant to
Section 2.1(a) only once; provided, however, that the Holder will be entitled to
exercise its rights  pursuant to Section 2.1(a) more than once if (x) the number
of  Registrable  Securities  that the  Holder  elected  to  include in any prior
registration was reduced by the managing  underwriter(s) or the Company,  as the
case may be, pursuant to Section 2.4, or (y) the Piggyback Registration in which
Registrable  Securities  were  to  be  included  was  withdrawn,   cancelled  or
permanently suspended pursuant to Section 2.5 or Section 4.2.

            Notwithstanding  the foregoing,  the Holder shall not be entitled to
exercise its  Piggyback  Registration  right if the Company shall have filed and
maintained  effective  a  shelf  registration   statement  for  the  Registrable
Securities for at least 180 days. 

      1.3  Expenses.  The  Company  shall pay,  and shall  reimburse  Holder for
paying,  any  expenses  incurred in  connection  with a  Piggyback  Registration
requested  pursuant  to  Section  2.1(a),  including,  without  limitation,  all
registration,  qualification,  printing  and  accounting  fees  and all fees and
disbursements  of counsel for the  Company,  provided  that Holder shall pay all
underwriting  discounts and commissions  with respect to Registrable  Securities
included in such  registration  statement  as well as fees or  disbursements  of
counsel, accountants or other professionals for Holder.

      1.4 Underwriting. If the registration of which the Company gives notice is
for a registered public offering involving an underwriting, the Company shall so
advise the Holder as a part of the  written  notice  given  pursuant  to Section
2.1(a),  and the right of the Holder to include  Registrable  Securities in such
registration  shall be  conditioned  upon  the  Holder's  participation  in such
underwriting  and the  entry  of the  participating  Holder  (together  with the
Company  and  other  holders   distributing   their   securities   through  such
underwriting)  into  an  underwriting  agreement  in  customary  form  with  the
underwriter or underwriters selected for such underwriting by the Company.

      1.5  Priority.  (a) If the  managing  underwriter(s)  (in  the  case of an
underwritten  registration)  or the  Company  (in the  case of  non-underwritten
registration)   should  reasonably  object  to  the  exercise  of  the  Holder's
registration  rights as set forth herein or if the managing  underwriter(s)  (in
the  case of an  underwritten  registration)  or the  Company  (in the case of a
non-underwritten registration) should reasonably determine that the inclusion of
the Registrable  Securities would adversely affect the offering  contemplated in
such  Registration  Statement,   and  based  on  such  determination  recommends
inclusion in such  registration of fewer or none of the 


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Registrable  Securities,  then securities  shall be included in such offering in
the following order of priority:

          if such registration as initially proposed by the Company was solely a
primary  registration of its securities,  (x) first, the securities  proposed by
the Company to be sold for its own account,  (y) second,  any  securities of the
Company  proposed  to be  included  in such  registration,  allocated  among the
holders  thereof in  accordance  with the  priorities  then  existing  among the
Company and such holders, and (z) third, any Registrable Securities requested to
be included in such registration by Holder pursuant to Section 2.1., pro rata on
the basis of the number of  Registrable  Securities  requested to be included by
Holder plus the number of any other  securities  of the  Company  proposed to be
included in such registration pursuant to any other Person's exercise of similar
"piggyback" registration rights granted by the Company;

         if such registration as initially  proposed by the Company was in whole
or in part requested by holders of securities of the Company, other than holders
of  Registrable  Securities  in their  capacities  as such,  pursuant  to demand
registration  rights,  (x) first, such securities held by the holders initiating
such registration and, if applicable,  any securities proposed by the Company to
be sold for its own account,  allocated in accordance  with the priorities  then
existing among the Company and such holders,  (y) second,  any securities of the
Company  proposed  to be  included  in such  registration,  allocated  among the
holders  thereof in  accordance  with the  priorities  then  existing  among the
Company and such holders, and (z) third, any Registrable Securities requested to
be included in such registration by Holder pursuant to Section 2.1., pro rata on
the basis of the number of  Registrable  Securities  requested to be included by
Holder plus the number of any other  securities  of the  Company  proposed to be
included in such registration pursuant to any other Person's exercise of similar
"piggyback" registration rights granted by the Company.

            Any securities  excluded  pursuant to the provisions of this Section
2.4  shall be  withdrawn  from  and  shall  not be  included  in such  Piggyback
Registration. 

           (a) Notwithstanding the provisions of Section 2.4(a), the Company, in
its sole and absolute  discretion  upon approval of its Board of Directors,  may
enter  into  agreements  granting  Persons  other  than the  Holder the right to
include  any  securities  issued or  issuable  to such  Persons  in a  Piggyback
Registration  on a pro rata basis with the  inclusion  of  Holder's  Registrable
Securities  (to the extent such Persons do not  expressly  consent in writing to
the  inclusion  of  such  securities  on  a  basis  subordinate  to  Registrable
Securities).

      1.6 Company's Obligations. The rights of Holder, under this Article II are
solely  piggyback in nature,  and nothing in this  Agreement  shall  prevent the
Company  from  reversing a decision  to file a  Registration  Statement  or from
withdrawing  or delaying any such  Registration  Statement  before it has become
effective.


HOLDBACK AGREEMENTS

      1.7 Restrictions on Public Sale by Holder.  Holder agrees, if requested in
writing by:

      the managing  underwriter or underwriters  in an underwritten  offering of
Registrable  Securities covered by a registration  statement filed pursuant to a
Piggyback Registration; or


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      the  managing  underwriter  or  underwriters  in an  underwritten  primary
offering of securities of the Company made pursuant to the Securities Act;

not to  effect  any  public  sale or  distribution  of any  Common  Stock or any
securities  convertible  into or  exchangeable  or exercisable for Common Stock,
including a sale  pursuant to Rule 144 (or any  successor  provision)  under the
Securities  Act  (except  to  the  extent  included  in  any  such  offering  or
distribution  pursuant to Section 2.1), during the period starting with the date
10 days prior to and ending on the earlier of the date 90 days after the closing
date of any  such  offering,  sale or  distribution  or 180 days  following  the
effective date of the registration statement filed in connection therewith.  

      1.8 No Participation in Other Securities Offerings.  The rights granted by
the  Company  hereunder  shall be the  exclusive  rights  granted to Holder with
respect to Registrable  Securities.  Except as otherwise provided herein, Holder
shall have no rights to participate in any offering of securities by the Company
to third parties,  including without  limitation,  any offering of Common Stock,
whether such offering is effected pursuant to registration  under the Securities
Act or pursuant to an exemption from registration thereunder.

      1.9 Release from  Restrictions.  The Company may, in its sole and absolute
discretion,  elect to waive the applicability in any particular  instance of the
provisions of Section 3.1 and Section 3.2.


REGISTRATION PROCEDURES

      1.10  Registration  Procedures.  In the  case of each  registration  to be
effected  by the Company in which any Holder is  participating  pursuant to this
Agreement,  the  Company  will keep the  Holder  advised  in  writing  as to the
initiation of each registration and as to the completion  thereof. In connection
with each such offering,  the Company shall as expeditiously as possible, at its
sole expense:  

           (a)  prepare  (and  afford  counsel  for the Holder up to 10 business
days'  opportunity to review and comment thereon) and file with the Commission a
registration  statement with respect to such Holder's Registrable Securities and
use its best efforts to cause such  registration  statement to become and remain
effective, for a period of at least 180 days or until the distribution described
in the registration  statement  relating  thereto has been completed,  whichever
shall first occur;

           (b) furnish to the Holder and to the  underwriters  of the securities
being  registered  such  number  of  copies  of  the   registration   statement,
preliminary prospectus, final prospectus and other documents incident thereto as
such underwriters and the Holder from time to time may reasonably request;

           (c)  prepare  (and  afford  counsel  for the Holder up to 10 business
days'  opportunity  to review and comment  thereon) and file with the Commission
such  amendments  and  supplements  to  such  registration   statement  and  the
prospectus  used  in  connection  with  such  registration  statement  as may be
necessary to comply with the  provisions of the  Securities  Act with respect to
the disposition of all securities covered by such registration  statement and to
keep the  registration  statement  effective for the period  specified in 4.1(a)
above;


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           (d) use its best  efforts  to  register  or qualify  the  Registrable
Securities covered by such registration statement under such other securities or
Blue Sky laws of such  jurisdictions  as shall be  reasonably  requested  by the
Holder  for  the  distribution  of the  Registrable  Securities  covered  by the
registration statement to be sold by the Holder; provided that the Company shall
not be required in connection  therewith or as a condition thereto to qualify to
do  business  or to file a general  consent  to  service  of process in any such
states or jurisdictions;

           (e)  enter  into an  underwriting  agreement  in  customary  form and
substance  reasonably  satisfactory to the Company,  the Holder and the managing
underwriter or underwriters of the public  offering of such  securities,  if the
offering is to be underwritten, in whole or in part;

           (f) notify the Holder, at any time when a prospectus relating thereto
covered by such  registration  statement is required to be  delivered  under the
Securities  Act,  of the  happening  of any  event  as a  result  of  which  the
prospectus included in such registration  statement, as then in effect, includes
an  untrue  statement  of a  material  fact or omits to  state a  material  fact
required to be stated  therein or necessary to make the  statements  therein not
misleading in the light of the circumstances then existing;

           (g)  furnish,  at the  request  of the  Holder  on the date  that any
Registrable  Securities  are to be  delivered  to the  underwriters  for sale in
connection with a registration  pursuant to this  Agreement,  if such securities
are being sold through  underwriters,  or, if such securities are not being sold
through underwriters,  on the date that the registration  statement with respect
to such securities  becomes effective,  (i) an opinion,  dated such date, of the
counsel representing the Company for the purposes of such registration,  in form
and substance as is customarily given to underwriters in an underwritten  public
offering,  addressed to the  underwriters,  if any, and to the Holder and (ii) a
letter,  dated such date, from the independent  certified public  accountants of
the  Company,  in form and  substance  as is  customarily  given by  independent
certified public accountants to underwriters in an underwritten public offering,
addressed to the underwriters, if any, and to the Holder;

           (h)  make  available  for  inspection  by  Holder,   any  underwriter
participating in any distribution pursuant to such registration  statement,  and
any attorney,  accountant or other agent retained by such Holder or underwriter,
all financial and other records, pertinent corporate documents and properties of
the Company as shall be  reasonably  necessary to enable them to exercise  their
due diligence  responsibility,  and cause the Company's officers,  directors and
employees  to supply all  information  reasonably  requested by any such Holder,
underwriter,  attorney, accountant or agent in connection with such registration
statement;


           (i) use its best efforts to list all Registrable  Securities  covered
by such registration statement on NASDAQ or such other securities exchange where
the Company's  securities are then listed as may be mutually  agreed upon by the
parties and such securities exchange; and

           (j) The Company will cause any  restrictive  legend  imprinted on the
certificates  evidencing the Shares to be removed at such time as all conditions
to transfer of  restrictive  securities,  as  applicable  to such shares and the
holder  thereof  are  satisfied.  The  Company may require an opinion of counsel
reasonably   satisfactory  to  the  Company  to  support  the  removal  of  such
restrictive legend.


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      1.11 Suspension of  Dispositions.  Holder agrees that, upon receipt of any
notice (a "Suspension Notice") from the Company of the happening of any event of
the kind which,  in the opinion of the counsel  for the  Company,  requires  the
amendment  or  supplement  of  any   prospectus,   such  Holder  will  forthwith
discontinue  disposition  of Registrable  Shares until  Holder's  receipt of the
copies of the  supplemented  or  amended  prospectus,  or until it is advised in
writing  by the  Company  that use of the  Prospectus  may be  resumed,  and has
received copies of any additional or supplemental filings which are incorporated
by reference in the prospectus,  and, if so directed by the Company, Holder will
deliver to the  Company  all  copies,  other than  permanent  file copies of the
Prospectus  covering such Registrable  Securities current at the time of receipt
of such notice.


INDEMNIFICATION

      1.12  Indemnification by the Company.  In the event of any registration of
any Registrable  Securities pursuant to this Agreement under the Securities Act,
the  Company   will,   and  hereby  does,   indemnify  and  hold  harmless  each
participating  Holder,  and  each of its  directors,  officers  and  controlling
persons, if any, against any losses,  claims,  damages or liabilities,  joint or
several,  to which  such  participating  Holder or any such  Person  may  become
subject under the Securities Act or otherwise,  insofar as such losses,  claims,
damages  or  liabilities  (or  actions  or  proceedings,  whether  commenced  or
threatened,  in  respect  thereof)  arise  out of or are based  upon any  untrue
statement or alleged  untrue  statement of any  material  fact  contained in the
registration  statement under which such Registrable  Securities were registered
under the  Securities  Act, any  preliminary  prospectus,  final  prospectus  or
summary prospectus contained therein, or any amendment or supplement thereto, or
any omission or alleged omission to state therein a material fact required to be
stated  therein or necessary  to make the  statements  therein,  in light of the
circumstances  under which they were made, not misleading,  and the Company will
reimburse  each  participating  Holder and each such  Person for any  reasonable
legal or any other expenses incurred by them in connection with investigating or
defending  any such loss,  claim,  liability,  action or  proceeding;  provided,
however,  that the  Company  shall not be liable in any such case to the  extent
that any such loss, claim, damage, liability (or action or proceeding in respect
thereof)  or  expense  arises  out of or is based  upon an untrue  statement  or
alleged  untrue   statement  or  omission  or  alleged  omission  made  in  such
registration  statement,  any such  preliminary  prospectus,  final  prospectus,
summary  prospectus,  amendment or supplement in reliance upon and in conformity
with written information furnished to the Company by any participating Holder or
any other Person who  participates  as an underwriter in the offering or sale of
such securities,  in either case, specifically stating that it is for use in the
preparation thereof; and provided, further, that the Company shall not be liable
to any  participating  Holder to the extent that any such loss,  claim,  damage,
liability (or action or proceeding in respect  thereof) or expense arises out of
such  participating  Holder's  failure  to  send  or  give a copy  of the  final
prospectus or supplement to the Persons asserting an untrue statement or alleged
untrue  statement  or  omission  or alleged  omission at or prior to the written
confirmation  of the  sale of  Registrable  Securities  to such  Person  if such
statement or omission was corrected in such final prospectus or supplement. Such
indemnity shall remain in full force and effect  regardless of any investigation
made by or on behalf of any  participating  Holder  or any such  underwriter  or
controlling  person and shall  survive the  transfer of such  securities  by the
Holder. 


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      1.13 Indemnification by Participating  Holders.  Each of the participating
Holders  whose  Registrable  Securities  are  included  or to be included in any
registration  statement,  as a condition to including Registrable  Securities in
such registration statement,  agrees to indemnify and hold harmless (in the same
manner and to the same  extent as set forth in Section  5.1) the  Company,  each
director of the Company,  each officer of the Company who signs the registration
statement  and each other  Person,  if any, who controls the Company  within the
meaning of the  Securities  Act,  and each other Person who  participates  as an
underwriter in the offering or sale of such securities and each other Person who
controls  any such  underwriter  within the meaning of the  Securities  Act with
respect to any untrue  statement or alleged untrue  statement of a material fact
in or  omission  or  alleged  omission  to  state  a  material  fact  from  such
registration statement, any preliminary prospectus,  final prospectus or summary
prospectus  contained therein,  or any amendment or supplement  thereto, if such
untrue statement or alleged untrue statement or omission or alleged omission was
made in reliance upon and in conformity  with written  information  furnished to
the Company by any participating  Holder specifically stating that it is for use
in the preparation of such registration statement, preliminary prospectus, final
prospectus,  summary  prospectus,  amendment or supplement;  provided,  that the
liability of the Holders  hereunder  shall be limited to the  proportion  of any
such loss, claim, damage,  liability or expense which is equal to the proportion
that the public  offering  price of the shares sold by such Holder  bears to the
total public offering price of all securities sold pursuant to the  registration
statement, but not to exceed the proceeds (net of the underwriting discounts and
commissions) received by such Holder from such sale. Such indemnity shall remain
in full force and effect regardless of any investigation made by or on behalf of
the  Company  or  any  such  director,  officer,  or  any  such  underwriter  or
controlling  person and shall  survive the  transfer of such  securities  by any
participating Holder.

      1.14 Notices of Claims.  Promptly after receipt by an indemnified party of
notice  of the  commencement  of any  action  or  proceeding  involving  a claim
referred to in Section 5.1 or 5.2,  such  indemnified  party will, if a claim in
respect thereof is to be made against an indemnifying party, give written notice
to the latter of the commencement of such action;  provided,  however,  that the
failure of any  indemnified  party to give notice as provided  herein  shall not
relieve the  indemnifying  party of its  obligations  under  Section 5.1 or 5.2,
except to the extent that the indemnifying party is actually  prejudiced by such
failure  to give  notice.  In  case  any  such  action  is  brought  against  an
indemnified  party,  unless in such indemnified  party's  reasonable  judgment a
conflict of interest between such indemnified and indemnifying parties may exist
in  respect  of  such  claim,  the  indemnifying  party  shall  be  entitled  to
participate  in and to  assume  the  defense  thereof,  jointly  with any  other
indemnifying  party  similarly  notified  to the extent  that it may wish,  with
counsel reasonably satisfactory to such indemnified party, and after notice from
the indemnifying  party to such  indemnified  party of its election so to assume
the  defense  thereof,  the  indemnifying  party  shall  not  be  liable  to the
indemnified party for any legal or other expenses  subsequently  incurred by the
latter in connection  with the defense  thereof other than  reasonable  costs of
investigation;  provided  that the  indemnified  party may  participate  in such
defense at the indemnified  party's  expense;  and provided,  further,  that all
indemnified parties shall have the right to employ one counsel to represent them
if, in the reasonable judgment of such indemnified  parties, it is advisable for
them to be  represented  by separate  counsel by reason of having legal defenses
which are different from or in addition to those  available to the  indemnifying
party,  and in that event the  reasonable  fees and expenses of such one counsel
shall  be paid by the  indemnifying  party.  If the  indemnifying  party  is not
entitled  to, or elects not to,  assume the  defense of a claim,  it will not be
obligated  to pay the  fees  and  expenses  of more  than  one  counsel  for the
indemnified  parties  with  respect  to such  claim,  unless  


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in the reasonable  judgment of any indemnified  party a conflict of interest may
exist  between such  indemnified  party and any other  indemnified  parties with
respect to such claim, in which event the indemnifying  party shall be obligated
to pay the fees and  expenses of such  additional  counsel  for the  indemnified
parties.  No indemnifying  party shall consent to entry of any judgment or enter
into any settlement  without the consent of the indemnified party which does not
include as an unconditional term thereof the giving by the claimant or plaintiff
to such  indemnified  party of a release  from all  liability in respect to such
claim or litigation. No indemnifying party shall be subject to any liability for
any settlement made without its consent, which consent shall not be unreasonably
withheld.

      1.15 Other Indemnification.  Indemnification  similar to that specified in
the preceding Sections of this Article V (with appropriate  modifications) shall
be given  by the  Company  and any  participating  Holder  with  respect  to any
required  registration or other qualification of securities under any federal or
state law or regulation of any governmental  authority other than the Securities
Act.

      1.16  Indemnification  Payments.  The  indemnification  required  by  this
Article V shall be made by periodic  payments of the amount  thereof  during the
course of the  investigation  or  defense,  as and when  bills are  received  or
expense, loss, damage or liability is incurred.

      1.17  Contribution.  If,  for  any  reason,  the  foregoing  indemnity  is
unavailable,  or is insufficient to hold harmless an indemnified party, then the
indemnifying  party  shall  contribute  to the  amount  paid or  payable  by the
indemnified  party as a result of the expense,  loss, damage or liability (a) in
such  proportion  as is  appropriate  to  reflect  the  relative  fault  of  the
indemnifying  party  on the one  hand and the  indemnified  party  on the  other
(determined  by reference to, among other things,  whether the untrue or alleged
untrue  statement of a material fact or omission or alleged  omission relates to
information  supplied by the indemnifying party or the indemnified party and the
parties'  relative intent,  knowledge,  access to information and opportunity to
correct or prevent such untrue statement or omission),  or (b) if the allocation
provided by clause (a) above is not  permitted by  applicable  law or provides a
lesser sum to the indemnified party than the amount otherwise payable hereunder,
in the  proportion as is  appropriate  to reflect not only the relative fault of
the indemnifying party and the indemnified party, but also the relative benefits
received by the indemnifying  party on the one hand and the indemnified party on
the  other,  as  well  as  any  other  relevant  equitable  considerations.   No
indemnified party guilty of fraudulent  misrepresentation (within the meaning of
Section 11(f) of the Securities Act) shall be entitled to contribution  from any
indemnifying party who was not guilty of such fraudulent misrepresentation.  The
liability  of the  holders  under  this  Section  5.6  shall be  limited  to the
proportion of any contribution  which is equal to the proportion that the public
offering  price of the  shares  sold by such  Holder  bears to the total  public
offering price of all securities sold pursuant to the registration statement but
not to exceed the  proceeds  (net of  underwriting  discounts  and  commissions)
received by such Holder from such sale.


INFORMATION BY PARTICIPATING HOLDERS

      1.18  Information  Regarding  Participating  Holders.  If any  Registrable
Securities are included in any  registration,  each  participating  Holder shall
furnish to the Company and any applicable underwriter such information regarding
such Holder and the distribution  proposed by such Holder as the Company or such
underwriter  may  reasonably


                                        9


request in writing and as shall be required in connection with any registration,
qualification or compliance referred to in this Agreement.


TRANSFER OF RIGHTS

      1.19 Transfer or Assignment.  The rights granted  hereunder by the Company
may be assigned or otherwise  conveyed to the Permitted  Transferees  of KMD. It
shall be a condition to any Transfer that (a) the Company shall have received an
opinion of counsel reasonably acceptable to it that such Transfer is effected in
accordance  with  applicable   federal  and  state  securities  laws,  (b)  such
transferee or assignee becomes a party to this Agreement or agrees in writing to
be  subject  to the  terms  hereof to the same  extent as if it were the  Holder
hereunder, and (c) the Company is given written notice of said Transfer, stating
the name and address of said  transferee and  identifying  the  securities  with
respect to which such registration rights are being assigned.


TERMINATION

      1.20 Termination.  This Agreement and the rights provided  hereunder shall
terminate  and be of no further  force and effect with respect to each Holder on
such date as such Holder no longer holds any Registrable Securities.


MISCELLANEOUS

      1.21 Remedies for Breach.  It is expressly  understood  that the equitable
remedies of specific  performance  and  injunction  shall be  available  for the
enforcement of the covenants and agreements herein, and that the availability of
these equitable  remedies shall not be deemed to limit any other right or remedy
to  which  any  party  to this  Agreement  would  otherwise  be  entitled.  

      1.22 Successors and Assigns. Subject to the provisions of Section 7.1, the
terms and  conditions  of this  Agreement  shall  inure to the benefit of and be
binding upon the respective successors,  assigns and transferees of the parties.
If any successor, assignee or transferee of any Holder shall acquire Registrable
Securities,  in any  manner,  whether by  operation  of law or  otherwise,  such
Registrable  Securities  shall  be  held  subject  to all of the  terms  of this
Agreement,  and by taking and holding such  Registrable  Securities  such Person
shall be conclusively  deemed to have agreed to be bound by all of the terms and
provisions hereof.

      1.23 Notices. All notices and other communications  provided for hereunder
shall be in writing and sent by registered  or certified  mail,  return  receipt
requested,  postage prepaid or delivered in person or by courier,  telecopier or
electronic  mail, and shall be deemed to have been duly given when received,  by
the party to whom such notice is to be given at its address set forth below,  or
at such  other  address  for the party as shall be  specified  by  notice  given
pursuant hereto:



            if to the Company, to:


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                  DIANON Systems, Inc.
                  200 Watson Boulevard
                  Stratford, Connecticut 06409
                  Attention:  Chief Executive Officer
                  Fax:  (203) 380-4138

            with a copy to:

                  Cadwalader, Wickersham & Taft
                  100 Maiden Lane
                  New York, NY 10038
                  Attention:  Dennis J.  Block, Esq.
                  Fax:  (212) 504-5557

            If to a Holder,  to such  Holder at the  address  set forth for such
Holder in the stock records of the Company.  

      1.24 Governing  Law. This  Agreement and any  controversy or claim arising
out of or relating to this Agreement  shall be governed by the laws of the State
of New York, without giving effect to the principles of conflicts of laws.

      1.25 Entire Agreement;  Amendments and Waivers. This Agreement constitutes
the entire  agreement among the parties  pertaining to the subject matter hereof
and  supersedes  all  prior   agreements,   understandings,   negotiations   and
discussions whether oral or written, of the parties. No supplement, modification
or waiver of this Agreement  shall be binding unless  executed in writing by all
parties. No waiver of any of the provisions of this Agreement shall be deemed or
shall  constitute  a  waiver  of any  other  provision  hereof  (whether  or not
similar),  nor shall such waiver constitute a continuing waiver unless otherwise
expressly provided.

      1.26  Counterparts.  This  Agreement  may  be  executed  in  two  or  more
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together  shall  constitute  one and the same  instrument.  Copies  of  executed
counterparts  transmitted by telecopy or other electronic  transmission  service
shall be considered original executed  counterparts for purposes of this Section
9.6.

      1.27  Severability.  In the event  that 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 any other provision of this Agreement.

      1.28  Headings.  The  headings of the  Articles  and  Sections  herein are
inserted for convenience of reference only and are not intended to be part of or
to affect the meaning or interpretation of this Agreement.

      1.29 Gender and Other  References.  Unless the context  clearly  indicates
otherwise,  the use of any gender pronoun in this  Agreement  shall be deemed to
include all other genders,  and singular references shall include the plural and
vice versa.

                           [SIGNATURE PAGE FOLLOWS]


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            IN  WITNESS   WHEREOF,   the  parties   hereto  have  executed  this
Registration Rights Agreement as of the day and year first above written.


                                       DIANON SYSTEMS, INC.



                                          By:  /s/  Kevin C. Johnson
                                             -----------------------
                                          Name:  Kevin C. Johnson
                                          Title:  President & CEO


                                       KYTO MERIDIEN DIAGNOSTICS, L.L.C.



                                          By:
                                          /s/ Ralph M. Richart
                                          ----------------------------
                                          Name:  Ralph M. Richart
                                          Title:  President of General
                                          Partner of Member






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