<PAGE>


Note:  Confidential treatment requested.  Exhibit omits information that has
       been filed separately with the Securities and Exchange Commission.      
                                                         1

                           JOINT DEVELOPMENT, LICENSE

                              AND SUPPLY AGREEMENT

         This Joint Development, License and Supply Agreement (this "Agreement")
is entered into as of the 14TH day of January,  1997 ("Effective  Date"), by and
between OSTEX INTERNATIONAL, INC., a Washington corporation having its principal
place of business  at 2203  Airport Way South,  Suite 400,  Seattle,  Washington
98134 ("Ostex"),  and HOLOGIC, INC., a Delaware corporation having its principal
place of business at 590 Lincoln Street, Waltham, MA 02154 ("Hologic").

                                    RECITALS

         A.  The  Washington  Research   Foundation,   a  nonprofit   Washington
corporation  ("WRF"),  is the owner, by way of assignment from the University of
Washington,  of all right,  title, and interest in certain technology  developed
out of research  conducted  by Dr.  David Eyre and  generally  described  as the
"Urinary Assay for Bone Resorption" (as more  particularly  defined herein,  the
"WRF Bone Resorption Technology").

         B.  Pursuant  to that  certain  Restated  Exclusive  License  Agreement
between  Ostex and WRF,  effective  June 29,  1992 as amended,  the  ("WRF/Ostex
Exclusive License Agreement"), WRF granted Ostex an exclusive, worldwide license
to make,  have  made,  assign,  sublicense,  lease,  develop,  enhance,  modify,
produce, reproduce, demonstrate, market, promote, sell, distribute, use, exploit
and otherwise  commercialize and prepare  derivations of the WRF Bone Resorption
Technology.

         C. Ostex engages in the research, development, manufacture, and sale of
diagnostic and therapeutic  products in the field of bone and mineral metabolism
in applications  related to bone  resorption and collagen and connective  tissue
degradation, and has developed a proprietary immunoassay to determine the levels
of NTx epitope  collagen  metabolite  resulting from bone resorption ("NTx Assay
Technology" as further defined in SECTION 1.15 hereof), which it has implemented
in  a  microtiter   format   suitable  for  use  in   centralized   laboratories
("OsteomarkAE Laboratory Test").

         D. Serex,  Inc., a New Jersey  Corporation  with its principal place of
business at 230 West Passaic Street,  Mayfield,  New Jersey 07607 ("Serex") also
engages in research and  development of diagnostic  products in various  fields,
including the field of bone and mineral metabolism,  and applications related to
bone  resorption  and  collagen  and  connective  tissue  degradation;  and  has
developed  a  proprietary  immunodiagnostic  format for  detection  of  analytes
associated  with  various  disease  states  and  conditions  (including  without

<PAGE>

limitation the technology embodied in the patents and patent applications listed
in ATTACHMENT D hereto (the "Serex Patent Rights")), together known as the Serex
Antibody  Release  Assay  ("SARA  Format").  Serex  has  also  developed  and is
continuing  to develop an  immunoassay  to determine  the levels of  metabolites
resulting  from  bone  resorption  (targeted  to a peptide  linked  pyridinoline
epitope  collagen and  potentially  to other  metabolites)  suitable for various
uses,  including  point of care and home or other  over-the-counter  ("OTC") use
("PLP Assay").

         E. Hologic engages in the research, development, manufacture, sale, and
lease  of  diagnostic  equipment  and  other  products  in  the  field  of  bone
metabolism,  including  its  lines  of  QDR  x-ray  bone  densitometers,  Sahara
ultrasound  bone  sonometers  and  associated   systems  for  analysis  of  bone
metabolism  data.  Pursuant to an agreement dated September 30, 1994 as amended,
(as  amended,  the  "Hologic/Serex  Agreement"),  Hologic  has  entered  into  a
cooperation with Serex under which Hologic has funded Serex's development of the
PLP Assay  for use with the SARA  Format,  and has  obtained  certain  exclusive
rights and licenses to distribute the products  resulting from this cooperation.
In an associated undertaking, Hologic has undertaken to develop a meter suitable
for point of care use to read assays in the SARA Format.

         F. Ostex and Hologic  desire to engage in a  development  project under
which  Hologic will cause Serex to implement  the NTx Assay  Technology  to work
with the SARA  Format in a strip  format  (the  "NTx  Meter  Strip")  and with a
Hologic-developed  stand-alone  meter for  point of care use (the "NTx  Meter"),
which NTx Meter Strip and NTx Meter are  collectively  referred to herein as the
"NTx Meter  System".  Hologic  will  arrange for  manufacture  of said NTx Meter
Strips and NTx Meters.

         G. Ostex desires to contribute to this development  project by granting
to Hologic a license to use the NTx Assay  Technology  in  connection  with this
development  project,  by providing "Critical Reagents" (as this term is defined
in SECTION 1.15 hereof)  needed for this  development  project at no charge,  by
contributing  to the costs of said  project,  and by selling  Critical  Reagents
needed for manufacture of the NTx Meter Strips at its manufacturing cost, all as
more specifically described in this Agreement.

         H. In return,  Hologic  and Ostex will each sell said NTx Meter  Strips
and Meters,  and shall  share the  profits  thereof  through  the  mechanism  of
reciprocal  royalties,  all as more  specifically  described in this  Agreement.
Hologic may also  integrate  its meter  technology  with and into other  Hologic
products, and may sell such products without royalty.

         I. Simultaneously  with this Agreement,  Ostex and Hologic have entered
into that certain  Co-Promotion  Agreement  providing  for the  co-promotion  of
Hologic  products  and Ostex's  OsteomarkAE  Laboratory  Test in its  microtiter
format in accord with the terms set out therein (the "Co-promotion Agreement").

                               TERMS OF AGREEMENT

         In  consideration  of the mutual  covenants  and  agreements  contained
herein,  and  for  other  good  and  valuable  consideration,  the  receipt  and
sufficiency of which are hereby acknowledged, the parties agree as follows:

<PAGE>

         1.       DEFINITIONS.  The following definitions shall apply throughout
                                this Agreement.

                  1.1 "Affiliate"  means,  with respect to any person or entity,
any  individual,   corporation,  company,  firm,  partnership  or  other  entity
controlled  by, in control  of, or under  common  control  with,  such person or
entity,  where "control" means direct or indirect legal or beneficial  ownership
of fifty  percent  (50%) or more of the shares,  business  interests,  or voting
securities of another corporation,  company,  firm, partnership or other entity,
or the right to fifty percent  (50%) or more of the income of such  corporation,
company, firm, partnership or other entity. Notwithstanding the foregoing, Serex
shall be considered an affiliate of Hologic.

                  1.2 "WRF Bone Resorption  Technology"  means all technology to
which Ostex has rights  relating to assays,  methods,  and materials,  including
Critical Reagents,  for measuring bone collagen  metabolites;  having first been
developed  from research  conducted by Dr. David Eyre,  owned by the  Washington
Research Foundation,  and licensed exclusively to Ostex. The WRF Bone Resorption
Technology includes,  without limitation,  the urinary diagnostic assay known as
the Osteomark immunoassay.

                  1.3 "Confidential  Information" means (a) any and all normally
non-public  information  communicated or disclosed by one party ("Discloser") to
the other party  ("Recipient")  describing or relating to the Disclosing Party's
business and marketing plans and strategies,  financial information, or customer
information,  and (b) any and all  information  communicated or disclosed by the
Discloser to Recipient describing or relating to the Disclosing Party's research
and development,  Know-How, inventions, trade secrets, technical data, formulae,
drawings,   designs,  software,   models,  samples,  kits,  processes,   product
development  data and information and other data and information  related to the
business of Discloser,  labeled or specified in writing as "Confidential" or the
equivalent,  or if orally disclosed,  labeled  "Confidential" or the equivalent,
and  reduced  to  writing  within  thirty  (30)  days of such  oral  disclosure;
provided,  however,  that  "Confidential  Information"  shall  not be  deemed to
include information which the Recipient can demonstrate by written proof: (i) is
now,  or  hereafter  becomes,  through  no fault  on the part of the  Recipient,
generally  known or  available;  (ii) is known by the  Recipient  at the time of
receiving such  information;  (iii) is furnished to others by Discloser  without
restriction  on  disclosure;  (iv) is hereafter  furnished to the Recipient by a
third party unrelated to Discloser,  as a matter of right and without any breach
of any duty of non-disclosure;  (v) is independently  developed by the Recipient
without use of or  reference  to any  Confidential  Information;  or (vi) is the
subject of express written permission to disclose provided by Discloser. Without
limiting the generality of the foregoing,  Confidential  Information may include
information developed during the course of this Agreement.

                  1.4  "COGS"  means  all  costs  of  materials  and  components
(including  purchase costs and royalties) and personnel expended on fabrication,
quality control, and regulatory documentation,  plus a portion of overhead based
on the portion of resources allocated to manufacturing and shipping,  calculated
in accord with generally accepted accounting principles.

<PAGE>

                  1.5 "Critical  Reagents" means the set of reagents supplied by
Ostex for use in the development of the NTx Meter Strips,  currently  consisting
of:  monoclonal  antibodies  or fragments  thereof,  for example the  monoclonal
antibody produced by hybridoma 1H11, that shows specific  immunoaffinity for the
NTx Epitope (at  concentrations to be agreed on,  appropriate for use in the NTx
Meter Test) antibody diluent;  analyte (NTx  Epitope)-containing  controls;  and
other  reagents.  Reagents  will be supplied by Ostex "in bulk,"  provided  that
Ostex shall also supply a reasonable number of Osteomark(R) Laboratory Test Kits
in a microtiter plate format for Serex use for comparison and control  purposes.
As of the effective date of this Agreement,  Critical  Reagents include the 1H11
monoclonal antibody,  diluent,  calibrators and controls.  These reagents may be
changed upon mutual agreement of the parties and upon reasonable notice to scale
up to commercial quantities. The term "Critical Reagents" shall also include any
improvement to or successor antibody(ies) with immunoaffinity to the NTx Epitope
or similar  epitopes  resulting from bone  resorption  which may be developed or
marketed by Ostex in any form during the term of this Agreement.

                  1.6  "Discovery"  means  any  scientific,   technological,  or
commercial invention, discovery, development,  improvement, Know-How, or product
resulting from the activities  contemplated by the parties under this Agreement,
whether or not the same is patentable.

                  1.7  "Distribution   Network"  shall  mean  a  party  to  this
Agreement  acting  as a  seller  together  with  its  authorized  resellers  and
sublicensees.

                  1.8  "Field of Use"  means use with the SARA  Format,  and the
associated  NTx Meter or other  Hologic meter  technology  for use as a point of
care device.

                  1.9  "First  Commercial  Sale"  means the first  Sale of a NTx
Meter  System  by  the  Distribution  Network  for a  value  in an  arms  length
transaction with an independent  third party following  approval for Sale by the
United States Food and Drug Administration of the NTx Meter System.

                  1.10     "Gross Profit" means Net Sales less COGS.

                  1.11 "Gross Sales" means gross receipts,  royalties,  fees and
other valuable  consideration of any kind received directly or indirectly by, or
credited to the benefit of the seller and  permitted  Affiliates  in  connection
with all Sales to end-users and third-party  distributors.  Without limiting the
generality of the foregoing,  Gross Sales include without limitation,  interest,
late  charges,  time-price  differentials  and other  receipts  or  credits of a
similar nature.

                  1.12  "Know-How"  means any  method,  information,  procedure,
process, composition of matter, biological material, or other subject matter.

                           1.12.1  "Hologic  Know-How"  means  Know-How  that 
has been  developed  or acquired by Hologic, prior to or during the term of 
this Agreement.


<PAGE>

                           1.12.2   "Ostex  Know-How"  means Know-How that has 
been developed or acquired by Ostex, prior to or during the term of this 
Agreement.

                           1.12.3   "Serex  Know-How"  means Know-How that has 
been developed or acquired by Serex, prior to or during the term of this 
Agreement.

                  1.13 "Hologic  Intellectual Property Rights" means all Hologic
Know-How,  trade secrets,  Confidential  Information,  Hologic patent rights and
other intellectual  property rights owned or controlled by Hologic  individually
or in  conjunction  with  others and  related  to the field of bone and  mineral
metabolism,   meter  technology,   biochemical  markers,  or  medical  practice,
including  but not limited to Hologic's  rights to Serex  Intellectual  Property
Rights pursuant to the Hologic/Serex Agreement.

                  1.14  "Serex  Intellectual  Property  Rights"  means all Serex
Know-How,  trade secrets,  Confidential  Information,  Serex Patent Rights,  and
other intellectual property rights owned or controlled by Serex and individually
or in  conjunction  with  others and  related  to the field of bone and  mineral
metabolism,  meter  technology,  biochemical  markers,  diagnostic  products and
methods, or medical practice, including but not limited to the PLP Assay and the
SARA Format.

                  1.15 "NTx  Assay  Technology"  means a urine-  or  serum-based
immunoassay  for bone collagen  metabolites  comprising an NTx Epitope,  and any
successor  immunoassay utilizing WRF Bone Resorption  Technology,  together with
associated controls and other products, the manufacture,  use, offer for sale or
Sale of which  would,  but for the  licenses  granted  herein,  infringe a Valid
Claim.

                  1.16 "Net Sales" means Gross Sales,  less normal and customary
trade, quantity,  and cash discounts allowed and actually taken,  allowances for
credits  granted or  returns,  and  commissions  paid or allowed to  third-party
distributors.

                  1.17 "NTx Epitope" means a conformational  structure  included
within the natural crosslinked  telopeptides from type I collagen,  to which the
monoclonal antibody (mAb) produced from the hybridoma 1H11 binds specifically by
immunoaffinity.

                  1.18  "Ostex  Intellectual  Property  Rights"  means all Ostex
Patent Rights, Ostex Know-How, trade secrets, Confidential Information statutory
and common-law  trademark rights, and other intellectual  property rights owned,
licensed or controlled by Ostex during the term of this Agreement and related to
the WRF Bone Resorption Technology.

                  1.19     "Ostex  Patent  Rights"  means all  rights of Ostex,
  as  licensee  under the  WRF/Ostex Exclusive License  Agreement,  in and 
to any and all subject matter claimed in or  disclosed  by U.S.  patents  and 
patent  applications   referred  to  in  the  WRF/Ostex  Exclusive  License
Agreement,  including  without  limitation  U.S. Patent  Application  Serial No.


<PAGE>

118,234   filed   November   6,   1987,   and  any   divisions,   continuations,
continuations-in-part  or reissues arising  therefrom or issuing  thereon,  U.S.
Patent No.  4,973,666 issued November 27, 1990, U.S. Patent No. 5,140,103 issued
August 18, 1992, U.S. Patent No. 5,300,434 issued April 5, 1994, U.S. Patent No.
5,320,970  issued June 14, 1994, U.S. Patent No.  5,532,169 issued July 2, 1996,
U.S. Patent No.  5,455,179  issued October 3, 1995,  U.S.  Patent No.  5,473,052
issued  December 5, 1995, U.S.  Patent No.  5,576,189  issued November 19, 1996,
U.S. Patent No.  5,472,884  issued December 5, 1995 along with any and all other
patent rights  applicable,  owned by WRF and licensed to Ostex,  and related to,
derived  from,  or claiming  priority  from any such U.S.  patent  applications,
including  without  limitation  International  Application  No.  PCT/US88/03722,
International  Application  No.  PCT/US90/7015,  International  Application  No.
PCT/US92/04104.
                  1.19A  "Hologic  Patent Rights" means all rights of Hologic in
and to any and all subject  matter  claimed in or disclosed by U.S.  patents and
patent  applications owned or assigned to Hologic relating to the subject matter
of the Hologic/Serex Agreement.

                  1.20 "Sale" means any and all transactions  whereby a party or
its Affiliates sell, lease, rent, or otherwise transfer or dispose of to (i) any
end-user,  including  without  limitation  any  physician's  office or  clinical
laboratory  purchaser,  or  (ii)  any  third-party  distributor,  any  right  of
ownership, or any other right to possession.

                  1.21 "Valid Claim" means a claim in any unexpired Ostex Patent
Right which has not been held invalid by a non-appealed or unappealable decision
by a court or other appropriate body of competent jurisdiction.

         2.       LICENSE GRANTS.

                  2.1 NTX METER  STRIP.  Ostex  hereby  grants to Hologic and to
Hologic's "permitted assigns" for the term of this Agreement, and Hologic hereby
accepts,  a nonexclusive,  worldwide,  nontransferable  license in and under the
Ostex  Patent  Rights  and Ostex  Know-How,  to  develop,  manufacture  and have
manufactured,  and to market,  promote, offer to sell, sell, distribute and have
marketed,  promoted,  sold and  distributed  in any country in the World  except
Japan,  the NTx  Meter  System  (incorporating  the  NTx  Assay  Technology  and
utilizing the Critical  Reagents) within the Field of Use, all in return for the
Ostex rights set out herein.

                  2.2      HOLOGIC OPTION TO MANUFACTURE.

                           2.2.1    CRITICAL  REAGENTS  FOR NTX METER  STRIP(S).
Ostex hereby grants Hologic an option,  exercisable by Hologic  pursuant to
the   terms  of   SECTION   6.3.3   below,   to  a   temporary,   non-exclusive,
nontransferable, royalty-bearing license under the Ostex Patent Rights and Ostex
Know-How to manufacture or have manufactured,  purify or have purified, Critical
Reagents at a manufacturing facility in the United States (or such other country
as the parties  may  agree),  for the sole  purpose of  manufacturing  NTx Meter
Strips for  distribution  within the Field of Use  pursuant to the terms of this
Agreement.


<PAGE>

                           2.2.2    The terms of any license granted  pursuant 
to SECTION 2.2.1 shall be subject to payment to Ostex of a royalty equal to
the  transfer   price  for  such  Critical   Reagents  had  such  Reagents  been
manufactured  and delivered by Ostex,  less a deduction  equal to Hologic's COGS
therefor,  provided  that  if such  COGS  exceeds  the  transfer  price  and the
resultant number is a negative  number,  Hologic shall take a credit against any
amounts due to Ostex pursuant to SECTION 7.4 of this Agreement.

                           2.2.3    Any  license  granted  pursuant  to the  
option of this  SECTION  2.2 shall be  revocable  by Ostex upon ninety (90)
days prior notice  accompanied by  demonstration  by Ostex that it has recovered
the  manufacturing  capacity to resume supply of Hologic's  anticipated needs as
forecasted  pursuant  to SECTION  6.3.1  hereof  (provided,  however,  that such
license  may be  revoked  no  sooner  than six (6)  months  following  Hologic's
exercise  of  the  option,  and  upon  reasonable  agreement  as to  appropriate
phase-out of Hologic production,  phase-in of Ostex production,  and coverage of
any Hologic start-up and termination  costs,  whereupon  Hologic will again have
available  to it, in the event of  subsequent  default by Ostex as  described in
SECTION 6.3.3, a license option under this SECTION 2.2.

                  2.3      EXPRESS  RESERVATION  OF  RIGHTS.  The  scope of  
     license  granted by Ostex to Hologic  hereunder  is limited by the scope of
the express grants set forth in this SECTION 2. Without  limiting the generality
of the foregoing:

                           2.3.1    RIGHTS  SPECIFICALLY  EXCLUDED  FROM SCOPE 
     OF GRANT TO HOLOGIC.  Ostex  retains all rights in the WRF Bone  Resorption
Technology and Ostex Intellectual Property Rights,  including without limitation
all rights with respect to all products,  applications,  fields of use,  markets
and  uses,  that are not  expressly  included  within  the scope of the grant of
rights to Hologic as set forth in this Agreement. This Agreement shall not under
any circumstances be construed or interpreted to provide for the grant, license,
or any  other  transfer  to  Hologic  or  Serex  of any  rights  in the WRF Bone
Resorption Technology, other than the right to use Critical Reagents supplied by
Ostex hereunder within the scope of the license as granted in this SECTION 2.

                           2.3.2    HOLOGIC AND SEREX.  Hologic and Serex shall
     retain  their  respective  ownership  and  control of all Hologic and Serex
Intellectual  Property Rights and other proprietary  rights and interests in and
relating to the SARA Format, meter technology, and PLP Assay.

                           2.3.3    ACTIONS  REQUIRING  OSTEX'S PRIOR WRITTEN  
     CONSENT.  Hologic shall not, without Ostex's prior written  consent,  which
consent may be  withheld  at Ostex's  sole  discretion,  manufacture  or use any
Critical  Reagent  other than as  provided  for within the scope of the  license
grants as set forth in this SECTION 2.

                           2.3.4    COMPULSORY  LICENSES.  Ostex and  Hologic 
     acknowledge  that the Ostex  Patent  Rights  are  subject to the rights and
limitations  of United  States Code,  Title 35,  Chapter 18, and  administrative
regulations thereunder, and equivalents thereof in other jurisdictions, and that
the grants of  licenses  under  SECTION 2 above are  subject to such  rights and
limitations.  In the event  that Ostex  receives  notice  that any  governmental
agency in any country or territory  having valid authority and  jurisdiction has


<PAGE>

granted,  or intends to grant or to cause to be granted,  a  compulsory  license
with  respect to all or any portion of the Ostex Patent  Rights,  Ostex shall so
notify  Hologic and shall grant that third party a license to exercise the Ostex
Patent Rights to the extent required by the  governmental  agency.  The grant of
such  license  to a third  party or the  taking of rights by or on behalf of any
government shall under no circumstances be considered a breach of this Agreement
by Ostex,  provided  that Hologic shall be deemed to have received an equivalent
license under the same terms and conditions.

                  2.4 OSTEX RIGHT TO DISTRIBUTE NTX METER SYSTEM. Hologic hereby
grants to Ostex and its  Affiliates  for the term of this  Agreement,  and Ostex
hereby  accepts,  a nonexclusive,  nontransferable  license in and under Hologic
Intellectual  Property Rights,  to market,  promote,  sell,  distribute and have
marketed, promoted, sold and distributed under Ostex's trademarks in any country
in the World,  the NTx Meter System all in return for the Hologic rights set out
herein.

         3.       SUPPLY OF CRITICAL REAGENTS.

                  3.1.  CRITICAL REAGENTS FOR DEVELOPMENT OF NTX METER STRIP(S).
Ostex shall supply to Hologic and to its designee,  Serex,  without charge, such
reasonable  quantities of Critical  Reagents as shall be necessary or useful for
the  purpose  of  developing  NTx  Meter  Strip(s)  pursuant  to the  terms  and
conditions of this Agreement, together with such reasonable consulting advice as
Hologic or Serex may request.

                  3.2 CRITICAL  REAGENTS FOR  MANUFACTURING  NTX METER STRIP(S).
Ostex  shall  sell  to  Hologic  (or  such   manufacturer(s)  as  Hologic  shall
designate),  and Hologic (or said  manufacturer(s))  shall  purchase from Ostex,
Critical  Reagents for the purpose of manufacturing  NTx Meter Strip(s) pursuant
to the terms and conditions of this Agreement.

                           3.2.1    Hologic  or its  designated  manufacturer(s)
     shall pay Ostex a  non-royalty  transfer  price for Critical  Reagents sold
pursuant to this SECTION 3 equal to Ostex' COGS therefor.

                           3.2.2    Payment for each shipment of Critical  
     Reagents shall be made by Hologic or its designated  manufacturer(s) within
30 days of the date of invoice,  it being agreed that such invoice  shall not be
dated prior to shipment of the Critical  Reagents to which such invoice relates.
In the event that Hologic or its designated manufacturer(s) fails to comply with
the payment terms of this SECTION 3, Ostex shall have the right,  in addition to
all other rights available under this Agreement,  to suspend further shipment of
Critical Reagents until such breach is cured.

                  3.3 THIRD-PARTY MANUFACTURING ON BEHALF OF OSTEX. In the event
that  Ostex  licenses  a third  party to  manufacture  Critical  Reagents  to be
supplied  under this  Agreement,  Ostex  shall  ensure and  provide  evidence to
Hologic  demonstrating  that such  third-party  manufacturer  complies with good
manufacturing  practices  (GMP)  and  all  applicable  governmental  regulations

<PAGE>

relating  thereto and is either in compliance with or working toward  compliance
with  the  quality  standards   established  by  the   International   Standards
Organization,  Rules 9000 et seq. and  amendments  or  successors  thereto ("ISO
9000").

                  3.4  PRODUCT  WARRANTY;  QUALITY  CONTROL.  Ostex  warrants to
Hologic and its designated  manufacturer(s)  that all Critical  Reagents sold by
Ostex hereunder shall (i) comply with the  specifications  set out in ATTACHMENT
3.4 hereof when used in accord with Ostex  instructions  for use, and amendments
thereto as mutually  agreed upon by the  parties,  (ii) be free from  defects in
material,  workmanship  and design,  and (iii) comply with all applicable  laws,
rules and  regulations  related  to the  manufacture  and  distribution  of such
product (to the extent  applicable  to a  manufacturer).  Without  limiting  the
generality  of  the  foregoing,   Ostex  warrants  that  all  Critical  Reagents
manufactured  and supplied  for the United  States  market under this  Agreement
shall  be  manufactured,   tested,  documented,  packaged,  and  transported  in
compliance with GMP requirements of the FDA including,  without  limitation,  21
CFR Part 820 and any  amendments  or successors  thereto;  and that all Critical
Reagents manufactured and supplied under this Agreement,  regardless of intended
market, shall be manufactured,  tested, documented,  packaged and transported in
compliance with Hologic's  reasonable  quality assurance  requirements.  Hologic
shall have the right to audit and inspect Ostex  facilities,  books, and records
to confirm such compliance.  Ostex further  represents that it is working toward
compliance with the quality standards  established by ISO 9000 and warrants that
it will comply with such standards when legally  required to do so. In the event
that Hologic or its designated  manufacturer(s)  demonstrates within one year of
receipt that any Critical Reagent  supplied  pursuant to this Agreement fails to
meet these specifications and warranties,  Ostex shall, as Hologic's sole remedy
for such failure,  immediately replace said product  (demonstrated by Hologic or
its  designated   manufacturer(s)  as  non-conforming  in  accord  with  Ostex's
reasonable  standard  procedures)  with  product  which  conforms  to the  above
specifications and warranties. These warranties shall not apply to any item that
is subjected to abuse,  stress,  or misuse;  or used in any manner  inconsistent
with applicable Ostex instructions.

                  3.5      DELIVERY.  All  Critical  Reagents  purchased  
under  this  Agreement  shall be  shipped F.O.B. Origin.

                  3.6 INVENTORY.  At all times during the  distribution  term of
this Agreement, Ostex shall supply and Hologic or its designated manufacturer(s)
shall keep  sufficient  inventory of Critical  Reagents to carry out  reasonable
demand or orders for NTx Meter Strip(s) without undue delay.

                  3.7 FACILITIES STANDARDS. At all times during the term of this
Agreement,  Hologic and its designated manufacturer(s) shall provide or cause to
be provided such warehousing and transport  facilities as are both  commercially
reasonable and adequate under the applicable regulations,  product requirements,
and industry standards of all relevant jurisdictions under this Agreement.

         4.  PRODUCT  MANAGEMENT  COMMITTEE.  Within  thirty  (30)  day  of  the
Effective Date, the parties shall form a Product Management Committee consisting

<PAGE>

of two (2) named  representatives each from Hologic and Ostex respectively,  and
one (1) named representative (non-voting) from Serex, which committee shall have
the   responsibility   to  oversee  and   coordinate   development,   marketing,
promotional,  Sales, and distribution  efforts and other activities  required or
permitted by this Agreement respecting the NTx Meter System. The committee shall
meet at least once per  quarter,  at  locations  and at times to be agreed,  and
shall undertake the responsibilities  set out in this Agreement,  as well as the
obligation  to  regularly  review  development   status,   marketing  and  sales
forecasts,  actual sales performance,  competitive  activities,  and promotional
plans.  The committee  shall attempt to operate by consensus,  and shall take no
action  without  approval of a majority of voting  members.  The  committee  may
delegate certain of its functions to subcommittees or individual  members.  Each
party  shall  cause its members to work  diligently  to promote  the  commercial
success of the NTx Meter  System.  Either  party may change its  representatives
assigned to said committee by fifteen (15) days advance  written notice provided
pursuant to SECTION 21 of this Agreement.

         5.       ROLE OF THE PARTIES IN THE DEVELOPMENT AND REGULATORY APPROVAL
                  OF THE NTX METER SYSTEM.

                  5.1 GOALS. The parties have established the development  goals
set out  herein,  which  goals are  anticipated  to be  accomplished  within the
general time periods set out therein, as said development goals may be specified
in more detail or amended from time to time, provided that Hologic shall use and
shall cause Serex to use its best commercial efforts to complete  development of
the    NTx    Meter    System    and    to    obtain     regulatory     
approval thereof for XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.

                  5.2  CONSULTATION  AND  AVAILABILITY OF OSTEX  KNOW-HOW.  Each
party shall perform the activities  assigned to it, and shall make available key
employees to provide consultation,  advice, assistance, and scientific direction
in  furtherance  of the  objectives  of this  Agreement.  Without  limiting  the
generality of the foregoing,  Ostex shall make available to Hologic and to Serex
personnel trained in and knowledgeable of the WRF Bone Resorption Technology and
performance  characteristics  of the NTx Assay  Technology.  Except as otherwise
specifically provided in this Agreement, each party shall bear its own costs and
expenses associated with all facilities, materials, and employee time devoted to
this effort.  Neither  party shall be obligated to disclose  their  Confidential
Information to the other,  except to the extent necessary for the performance of
each party's obligations under this Agreement.

                  5.3 SEREX  ROLE.  Hologic  shall  cause  Serex to use its best
commercial efforts,  pursuant to the Hologic/Serex  Agreement,  to (a) integrate
the Ostex NTx Assay  Technology  to work with the SARA  Format to create the NTx
Meter  Strip;  (b)  cooperate  with  Hologic to develop  the NTx Meter;  and (c)
cooperate  with  Hologic  and Ostex in the  conduct of  clinical  trials and the
obtaining of regulatory approvals for the NTx Meter System as a whole.

                  5.4      HOLOGIC  ROLE.  Pursuant to the  Hologic/Serex  
     Agreement,  Hologic shall (a) cooperate with Serex in connection  with, and
continue     to    fund,     development     of    the    NTx    Meter     Strip

<PAGE>

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX;
(b)    arrange,    manage    and   fund    development    of   the   NTx   Meter
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX;    and   (c)
arrange,  manage,  and fund  conduct of  clinical  trials and the  obtaining  of
regulatory   approvals   for   the   NTx   Meter   System    XXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.

                  5.5.     OSTEX ROLE.

                           5.5.1    GENERALLY.  Pursuant to  SECTIONS  2.1 and 
                                    3.1 of this  Agreement,  Ostex shall
                                    ---------                -------------    
(a) provide the license and Critical Reagents specified  therein;  (b) cooperate
with Hologic to develop the NTx Meter and (c)  cooperate  with Hologic and Serex
in the conduct of clinical trials and the obtaining of regulatory  approvals for
the NTx Meter System.

                           5.5.2    OSTEX FUNDING.  In addition, Ostex shall 
reimburse Hologic for XXXXXXXXXXXX of Hologic's funding paid out
in support of Serex's development  efforts, Meter  
development,  support of clinical  trials and regulatory  approval,  upon
receipt  of  Hologic's  invoice  to Ostex for the  previous  calendar  quarter's
expenses, to a maximum of XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
(the "Maximum Cost") which is one-hundred ten percent (110%) of the total of the
amounts set out in SECTION 5.4 above.  If at any time,  it appears that the cost
of the Serex  development  effort  for the NTx Meter  System  will  exceed  said
Maximum Cost, the parties will meet and use their best efforts to negotiate,  in
good faith, an appropriate
agreement  to allocate  any such  excess.  Failing  agreement,  either party may
terminate this Agreement  without  penalty upon thirty (30) days advance written
notice to either  party,  provided  that the other  party may agree  during such
notice period to reimburse the entire excess,  in which case  royalties  payable
pursuant  to  SECTIONS  7.3 and 7.4 shall be  adjusted  to reflect  the  overall
percentage of funding paid by each party during the period beginning  January 1,
1997.

                           5.5.3    ACCESS TO  CLINICAL  DATA.  Ostex  shall 
     provide  Hologic and Serex with full access to all clinical  trial data and
regulatory submissions, and make available all urine samples, collected by Ostex
that pertain to the NTx Assay  Technology  and to the  activities of Hologic and
Serex under this Agreement.  It is acknowledged  that such  information  will be
subject to the  confidentiality  provisions set out in this Agreement as well as
confidentiality  provisions  necessary  to protect  patient  privacy;  provided,
however, that such information may, as necessary and appropriate, be transmitted
to proper  regulatory  authorities in connection  with the seeking of regulatory
product approvals.
                           5.5.4.   TECHNICAL   SUPPORT.   Ostex  shall  assist
  Hologic  and  Serex,  at  either's
reasonable request, in the technical training of a mutually determined number of

<PAGE>

Hologic  and/or  Serex's  employees,  such  training  to  include  provision  of
information as to the nature, use and proper care of Critical Reagents. Any such
training shall be provided at Ostex's  principal place of business,  and Hologic
shall be solely responsible for all costs of transportation,  lodging, and other
expenses of trainees incidental to such training.  During the term hereof, Ostex
shall use its commercially  reasonable efforts to respond to technical questions
or problems  which may arise from time to time in  connection  with the Critical
Reagents, WRF Bone Resorption Technology and Ostex Intellectual Property.

         6.       ROLE OF THE PARTIES IN MANUFACTURE AND COMMERCIALIZATION 
                  OF NTX METER TEST.

                  6.1  MANUFACTURING.  Pursuant to the Hologic/Serex  Agreement,
Hologic shall,  within a reasonable time period following FDA approval,  develop
the  capacity  to  manufacture  or  have  manufactured   reasonable   commercial
quantities of the NTx Meter and NTx Meter Strips.  Hologic may have Serex and/or
third parties  manufacture and package the NTx Meter Strips  (provided that they
have agreed to be bound by the terms of this Agreement, including its provisions
relating  to  confidentiality),  and may  manufacture  the NTx  Meter  itself or
utilize third parties to do so,  provided that Hologic shall first furnish Ostex
with evidence  demonstrating  any such third party's  capability to  manufacture
such  NTx  Meter  Strips  or NTx  Meters  pursuant  to GMP  and  all  applicable
regulatory requirements.

                  6.2  COMMERCIALIZATION.  Six months  prior to the  anticipated
First Commercial Sale of NTx Meter Systems under this Agreement, but in no event
longer than 24 months from the  effective  date of this  Agreement,  Hologic and
Ostex,  acting  through  the  Product  Management  Committee,  shall  agree on a
marketing  plan for said NTx Meter  Systems for the  following  twelve months (a
"Marketing Year") that will be appended to this Agreement as ATTACHMENT 6.2. The
parties anticipate that such Attachment will cover marketing activities and will
require each party to spend, individually, XXXXXXXXXXXXXXXXXXXXXX of anticipated
total Gross Sales by both  parties  together of NTx Meter  Strips and NTx Meters
for such year (as this number is determined by the Product Management Committee)
on marketing activities  therefor.  The Product Management Committee shall agree
on a new marketing  plan for each  subsequent  Marketing Year during the term of
this Agreement; provided that such marketing plan shall not require either party
to spend XXXXXXXXXXXXXXXXX of that party's individual Gross Profit received
from its Sales of NTx Meter Systems during the immediately  preceding  Marketing
Year (not including royalties received from the other party pursuant to SECTIONS
7.3 or 7.4 hereof), provided further that if the Product Management Committee is
not able to agree on a marketing plan for any such  subsequent  Marketing  Year,
the  marketing  plan  (including  budgetary  allocations)  for  the  immediately
preceding  Marketing Year shall be repeated with expenditures  equivalent to the
dollar  expenditures of such preceding  Marketing Year. If either party does not
spend the amount so designated  pursuant to the marketing plan for any Marketing
Year of this  Agreement,  the other party shall, in addition to any other remedy
provided under this  Agreement,  be entitled to take a credit against  royalties
payable by it for the subsequent Marketing Year equal to the shortfall. Said

<PAGE>

Product Management  Committee will also establish for each Marketing Year of the
term a  designated  quantity of NTx Meter  Strips to be  purchased by each party
pursuant to this Agreement,  and distributed as  "promotional  samples"  without
customer  charge,  and without royalty to either party.  For the first Marketing
Year, the parties expect to designate not less than 30% of the  anticipated
production of NTx Meter Strips as such "promotional  samples" provided that this
percentage may be revised by the Product Management Committee in light of market
conditions and strategy, allocated 50% to each party or as otherwise agreed.

                  6.3  Supply of  Critical  Reagents.  Ostex  shall use its best
commercial   efforts  to  supply  the  need  of  Hologic   and  its   designated
manufacturer(s)  for  Critical  Reagents as necessary to meet the demand for NTx
Meter Systems, in accordance with purchase orders received by Ostex from Hologic
and its designated manufacturer(s), and in SECTIONS 6.3.1 AND 6.3.2 below.

                           6.3.1    FORECAST OF DEMAND.  Within sixty days of 
     the  start  of  each   calendar   quarter,   Hologic   or  its   designated
manufacturer(s)  shall  deliver to Ostex a "rolling"  forecast of  quantities of
Critical Reagents to be purchased by Hologic and its designated  manufacturer(s)
and supplied by Ostex during each month of the  following  quarter,  and each of
the subsequent  three quarters (the "Rolling  Forecast").  Each Rolling Forecast
shall be considered a purchase order with respect to the  forecasted  demand for
Critical Reagents over the first three months thereof. The forecasted demand for
the first  subsequent  quarter  shall be relied on by Ostex for  purposes of its
manufacturing and supply obligations  hereunder,  but Hologic and its designated
manufacturer(s)  may vary from its initial  forecast for such quarter by no more
than twenty-five percent (25%). The forecasted demand for the final two quarters
of each  Rolling  Forecast  shall be used by Ostex for  planning  purposes,  but
Hologic  and its  designated  manufacturer(s)  shall not be bound by its initial
forecast(s),  nor shall Hologic or its designated  manufacturer(s)  be liable to
Ostex with respect to any changes thereto.

                           6.3.2  ALLOCATION  OF  PRODUCTION.  In the event 
     that Ostex does not meet the demand for Critical  Reagents ordered pursuant
to SECTION 6.3.1,  Ostex shall allocate overall  production of Critical Reagents
(whether   manufactured   or  purchased,   and  whether  for  Ostex's   internal
manufacturing or for Sale) such that Hologic and its designated  manufacturer(s)
receives  the same  proportion  of the amount of the  Critical  Reagents  it has
ordered  (pursuant  to  SECTION  6.3.1  hereto)  as Ostex  allocates  to its own
manufacture of products utilizing the NTx Assay Technology,  or to its otherwise
most favored non-end-user customer, whichever proportion is greater (measured as
a proportion  of total units of  production),  provided  that Ostex shall not be
required to sell to Hologic  and its  designated  manufacturer(s)  any more than
thirty percent (30%) of its total  production of any Critical Reagent during any
quarter.

                           6.3.3    EXERCISE  OF  MANUFACTURING  OPTION.  In 
the event  that Ostex does not for any
reason,  for a period of thirty (30) days, meet (through internal or third-party
manufacture),  Hologic's demand for Critical  Reagents which comply with SECTION
3.4 hereof, ordered pursuant to SECTION 6.3.1 hereof, Hologic shall be entitled,
upon  fifteen (15) days written  notice,  to exercise the option to  manufacture
such Critical Reagents  described in SECTION 2.2 hereof. Any Hologic exercise of
said option shall not relieve Ostex of its obligations  pursuant to this SECTION
6.3.  Upon any Hologic  exercise of said option,  Ostex shall provide to Hologic
subject  to the  provisions  of SECTION 10 of this  Agreement,  all  information

<PAGE>

necessary to so manufacture such Critical Reagents,  provided that Hologic shall
not disclose to Serex any  Confidential  Information  so  disclosed  without the
prior written approval of Ostex which approval may be conditioned or withheld at
Ostex's sole discretion.

                  6.4  PUBLICATIONS.  Each party shall,  throughout  the term of
this Agreement,  use its continuing  commercially  reasonable efforts to develop
documentation and publish scientific articles directly or indirectly  supporting
the  clinical  utility  of the  NTx  Meter  System.  Such  publications  will be
submitted to the other party for review and approval prior to  publication,  and
shall be subject to the requirements of SECTION 16.2 hereof regarding the use of
trademarks.

         7.       ROLE OF THE PARTIES IN THE SALES OF THE NTX METER TEST.

                  7.1 The parties'  general  agreement is that Hologic and Ostex
shall each sell NTx Meter Strips and NTx Meters as they see fit, and shall share
the  profits  associated   therewith  in  accord  with  the  reciprocal  royalty
mechanisms more specifically described in this Section.

                  7.2 OSTEX  PURCHASE  OF NTX METER  STRIPS AND  METERS  Hologic
shall use its  commercially  reasonable  efforts  to supply the need of Ostex to
meet the demand for NTx Meter Strips and NTx Meters, in accordance with purchase
orders  received  by Hologic  from  Ostex,  and in  accordance  with the rolling
forecast  and  allocation  provisions  specified  in Sections  7.2.10 and 7.2.11
below.

                           7.2.1    Ostex shall pay Hologic a non-royalty  
transfer  price for NTx Meter Strips and
NTx Meters sold pursuant to this Section equal to XXXXXXXXXXXXXXX  therefor
(including  any extra  charge  for  Ostex-requested  modifications  to  standard
packaging as may be agreed).

                           7.2.2    Payment for each  shipment of NTx Meter  
Strips and NTx Meters shall be made by
Ostex  within 30 days of the date of invoice,  it being agreed that such invoice
shall not be dated prior to  shipment of the NTx Meter  Strips and NTx Meters to
which such invoice relates.

                           7.2.3    THIRD-PARTY  MANUFACTURING  ON BEHALF OF  
HOLOGIC.  In the event  that  Hologic
licenses  a third  party to  manufacture  NTx Meter  Strips or NTx  Meters to be
supplied  to Ostex  under this  Agreement,  Hologic  shall  ensure  and  provide
evidence to Ostex demonstrating that such third-party manufacturer complies with
good manufacturing practices (GMP) and all applicable  governmental  regulations
relating  thereto and is either in compliance with or working toward  compliance
with  the  quality  standards   established  by  the   International   Standards
Organization,  Rules 9000 et seq. and  amendments  or  successors  thereto ("ISO
9000").

                           7.2.4    PRODUCT WARRANTY; QUALITY CONTROL. Hologic 
warrants to Ostex  that all NTx
Meter Strips and NTx Meters sold by Hologic to Ostex  hereunder shall (i) comply
with the product specifications attached hereto as ATTACHMENT 7.2.4 when used in
accord with applicable Hologic instructions,  as modified by mutual agreement of
the parties, (ii) be free from defects in material,  workmanship and design, and
(iii) comply with all  applicable  laws,  rules and  regulations  related to the

<PAGE>

manufacture  and  distribution  of such product (to the extent  applicable  to a
manufacturer).  Without  limiting  the  generality  of  the  foregoing,  Hologic
warrants that all NTx Meter Strips and NTx Meters  manufactured and supplied for
the United States market under this  Agreement  shall be  manufactured,  tested,
documented, packaged, and transported in compliance with GMP requirements of the
FDA  including,  without  limitation,  21 CFR  Part  820 and any  amendments  or
successors  thereto;  and that all NTx Meter Strips and NTx Meters  manufactured
and supplied  under this  Agreement,  regardless  of intended  market,  shall be
manufactured,  tested,  documented,  packaged and transported in compliance with
appropriate quality assurance requirements agreed to by the parties. Ostex shall
have the right to audit and inspect Hologic  facilities,  books,  and records to
confirm such  compliance.  Hologic  further  represents  that is working  toward
compliance with the quality standards  established by ISO 9000 and warrants that
it will comply with such standards when legally  required to do so. In the event
that Ostex  demonstrates  within one year of receipt  that any product  supplied
pursuant to this Agreement  fails to meet these  specifications  and warranties,
Hologic  shall,  as Ostex's sole remedy for such  failure,  replace said product
(returned  by Ostex to the factory  pursuant to  Hologic's  reasonable  standard
return  procedures) with product which conforms to the above  specifications and
warranties,  provided  that Hologic  shall not be obligated to replace NTx Meter
Strips distributed as "Promotional Samples" which pass Hologic quality assurance
tests and comply  with all FDA and other  governmental  regulations  relating to
such Promotional  Samples.  These warranties shall not apply to any item that is
subjected to abuse,  stress, or misuse; or used in any manner  inconsistent with
applicable  Hologic  instructions;  or insofar as any such warranty violation is
caused by Ostex's violation of its warranties set out in SECTION 3.4 hereof.

                           7.2.5    CUSTOMS  AND  TAXES.  With  respect  to  
international  shipments  of any goods
purchased, sold, distributed, or otherwise transferred hereunder,  including the
Critical  Reagents,  the purchasing  party shall be responsible for clearing all
such goods through customs and shall pay any and all taxes and/or duties imposed
by any governmental authority in connection therewith.

                           7.2.6    DELIVERY.  All NTx Meter  Strips and NTx 
Meters  purchased  by Ostex under this
Agreement shall be shipped FOB manufacturer's dock.

                           7.2.7    INVENTORY.  At all  times  during  the  
distribution  term of  this  Agreement,
Hologic  shall  supply and Ostex shall keep  sufficient  inventory  of NTx Meter
Strips and NTx Meters to carry out reasonable demand for orders therefor without
undue delay.

                           7.2.8    FAILURE OF  PAYMENT.  In the event that 
Ostex  fails to comply with the payment
terms of this Section,  Hologic  shall have the right,  in addition to all other
rights available under this Agreement,  to suspend further shipment of NTx Meter
Strips and NTx Meters until such breach is cured.

                           7.2.9    FACILITIES  STANDARDS.  At all times 
during the term of this  Agreement,  Ostex
shall provide or cause to be provided such warehousing and transport  facilities
as  are  both   commercially   reasonable  and  adequate  under  the  applicable
regulations,  product  requirements,  and  industry  standards  of all  relevant
jurisdictions under this Agreement.


<PAGE>

                           7.2.10   FORECAST OF DEMAND.  Within thirty days of
the start of each calendar  quarter,
Ostex shall  deliver to Hologic a "rolling"  forecast of the  quantities  of NTx
Meter  Strips and NTx Meters to be  purchased  by Ostex and  supplied by Hologic
during each month of the following  quarter,.  and each of the subsequent  three
quarters (the `Rolling  Forecast").  Each Rolling Forecast shall be considered a
purchase  order with respect to the  forecasted  demand for NTx Meter Strips and
NTx Meters over the first three months  thereof.  The forecasted  demand for the
first  subsequent  quarter  shall be relied on by Hologic  for  purposes  of its
manufacturing  and  supply  obligations  hereunder,  but Ostex may vary from its
initial forecast for such quarter by no more than twenty-five percent (25%). The
forecasted  demand for the final two quarters of each Rolling  Forecast shall be
used by  Hologic  for  planning  purposes,  but Ostex  shall not be bound by its
initial  forecast(s),  nor shall Ostex be liable to Hologic  with respect to any
changes thereto.

                           7.2.11   ALLOCATION  OF  PRODUCTION.  In the event 
that Hologic does not meet the demand
for NTx Meters or NTx Meter Strips ordered  pursuant to SECTION 7.2.10,  Hologic
shall  allocate  overall  production  thereof such that Ostex  receives the same
proportion  of the amount of the NTx Meters and NTx Meter  Strips it has ordered
(pursuant to SECTION 7.2.10 hereto) as Hologic allocates for its direct sale, or
to its otherwise most favored  non-end-user  customer,  whichever  proportion is
greater  (measured as a proportion of total units of production),  provided that
Hologic  shall not be required to sell to Ostex and any more than fifty  percent
(50%) of its total production during any quarter.

                  7.3 OSTEX ROYALTY ON SALES OF NTX METER STRIPS AND NTX METERS.
Subject to the terms of SECTION  7.5  hereof,  Ostex shall pay to Hologic a
royalty             equal             to             XXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.  Ostex  shall  make the  royalty
payments  required by this Section not later than  forty-five (45) calendar days
following  the end of each  calendar  quarter.  At such time,  Ostex  shall also
provide  Hologic with a full  accounting of units disposed of, Gross Sales,  Net
Sales, COGS, and Gross Profits attributable thereto for said quarter.

                  7.4  HOLOGIC  ROYALTY  ON SALES OF NTX  METER  STRIPS  AND NTX
METERS.  Subject  to  the  terms  of  SECTION  7.5  hereof,  Hologic  shall  pay
to    Ostex    a     royalty     equal     to     XXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX., provided that Hologic shall not
be required to make any royalty  payment  with  respect to  dispositions  of NTx
meter technology  incorporated  into or sold as a package with or part of, other
Hologic equipment, XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.  Hologic shall make the
royalty  payments  required  by this  Section  not later  than  forty-five  (45)
calendar days following the end of each calendar quarter.  At such time, Hologic
shall also  provide  Ostex with a full  accounting  of units  disposed of, Gross
Sales, Net Sales, COGS, and Gross Profits attributable to its Sales of NTx Meter
Strips,  NTx Meters,  and NTx meter technology (but not other Hologic  equipment
into which said technology may be incorporated or packaged) for said quarter.

                  7.5  ADJUSTMENT TO  ROYALTIES.  Following the end of the first
year period  beginning with the First  Commercial Sale, and each subsequent year

<PAGE>

period,  if either  party's  Gross Sales of NTx Meter  Strips for the prior
year period was not equal to or greater than XXXXXXXXXXX XXXXXXXXXXXXXXX by both
parties of such NTx Meter Strips,  the royalty  payable on said NTx Meter Strips
for the  following  year  period by "the party with the larger  Sales"  shall be
adjusted  downward  by  XXXXXXXXXXXXXXXXXXXX  that the total  Sales of NTx Meter
Strips by  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  of such NTx Meter Strips, unless
"the party with the larger Sales" waives this adjustment.

                  7.6 SERIOUS INJURY.  Each party shall within twenty-four hours
advise the other by telephone,  (with follow-up hard copy, receipt confirmed) of
any adverse  effect or  malfunction  related to the NTx Meter  Strips or the NTx
Meter or the Critical Reagents  (whether  incorporated in NTx Meter Strips or in
any other product, including but not limited to the OsteomarkAE Laboratory Test)
of which the notifying party gains  knowledge  during the term of this Agreement
that may have caused or contributed  to, or should it reoccur is likely to cause
or contribute to, serious injury,  illness,  or death. The notifying party shall
include in the  notification  the name,  address,  and  telephone  number of the
person or entity  purchasing  the product in question,  the name,  address,  and
telephone of the patient (if different), and the lot or serial number of the NTx
Meter Strip or NTx Meter involved in the incident, as appropriate.

                  7.7 PRODUCT  RECALL.  If either party  believes that a product
recall is necessary or appropriate,  it will promptly notify the other,  and the
parties will (unless such recall is required by law) discuss whether such recall
is necessary or appropriate, and shall discuss the manner in which any agreed or
required  recall shall be conducted.  If a recall is not required by law and the
parties  cannot agree  whether the recall is necessary  or  appropriate,  either
party may elect to conduct the recall in question  The parties  shall  cooperate
with each other in  conducting  any such  recall.  All out of pocket  costs of a
required or agreed recall  insofar as such recall  relates to Critical  Reagents
(except printing and mailing costs incurred to notify customers of such recall),
shall be borne by Ostex.  All out of pocket costs of a required or agreed recall
except  insofar as such  recall  relates to  Critical  Reagents or the NTx Assay
Technology ( except  printing and mailing costs incurred to notify  customers of
such  recall),  shall be borne by  Hologic.  All  costs of a recall to which the
parties  have not agreed  shall be borne by the party that elects to conduct the
recall,  provided that if a court of competent jurisdiction determines that said
recall was caused by (i) the fact that any  Critical  Reagents  or the NTx Assay
Technology  were in violation of applicable  law or the terms of this  contract,
Hologic may obtain  reimbursement by Ostex of all reasonable out of pocket costs
and expenses of such recall  (except for printing and mailing costs  incurred to
notify  customers  of such  recall),  or (ii) the fact that any NTx Meter or NTx
Meter  Strip(s) were  otherwise in violation of  applicable  law or the terms of
this contract,  Ostex may obtain  reimbursement by Hologic of all reasonable out
of pocket  costs and  expenses of such recall  (except for  printing and mailing
costs  incurred to notify  customers of such recall.  Each party shall  maintain
complete  and  accurate  records of all product  sold by it for such  periods as
required by law.  Nothing in this Section  shall be construed to modify or limit
any legal obligation of either party with respect to any recall.

                  7.8  CORRECTIVE   ACTION.   If  any  government   agency  with
jurisdiction  shall request or order any  corrective  action with respect to any
Critical Reagent, or NTx Meter or NTx Meter Strips, including but not limited to

<PAGE>

any recall, customer notice, restriction, change, market action, or modification
of the product in question, and the cause or basis for such corrective action is
primarily  attributable  to a condition,  fact, or action that (i) constitutes a
breach  by a  party  of any  of its  warranties,  representations  or  covenants
contained  herein,  or (ii) a party knew or should have known would require such
corrective  action;  then such party shall be liable for and shall reimburse the
other  party  for all  costs  incurred  as a result  of such  action,  including
replacement cost of any product affected thereby.

         8.  BOOKS AND  RECORDS;  AUDITS.  Each  party to this  Agreement  shall
maintain  accurate  books and records with respect to all Critical  Reagents and
NTx Meters and NTx Meter Strips. Upon the request of the other party, each party
will provide the requesting  party or its  independent  public  accountant  with
access,  but no more than once per calendar year,  during regular business hours
and upon reasonable advance prior notice, to all accounting records necessary or
appropriate to verify amounts owed.  Any  adjustment  determined  appropriate by
such audit shall be due and payable within thirty (30) days following completion
of such audit,  together with  interest  calculated at a rate equal to the prime
lending rate reported in the Wall Street Journal for the last day of the audited
period plus two percent (+2%), or the maximum interest rate then permitted under
the laws of  Massachusetts,  whichever  rate is lower.  All fees for such audits
shall be borne by the requesting party unless the audit shows an under reporting
of amounts  due of five  percent  (5%) or more,  in which case the costs of said
audit shall be borne by the party being audited.

         9. OWNERSHIP OF  DISCOVERIES.  It is the intent of the parties that the
ownership of any and all Discoveries  resulting from this Agreement,  regardless
of inventorship,  shall: (a) vest solely in Ostex to the extent that such rights
relate exclusively to the NTx Assay Technology;  and (b) vest solely in Serex to
the extent that such rights relate  exclusively to the SARA Format or adaptation
of the NTx Assay Technology for use with the SARA Format; and (c) vest solely in
Hologic to the extent that such rights  relate  exclusively  to the NTx Meter or
use of NTx Meter  Strips with the NTx Meter;  and (d) in all other cases vest in
the party or parties of the inventor.

         10.  OBLIGATION  NOT TO DISCLOSE  CONFIDENTIAL  INFORMATION.  Recipient
shall not at any time,  and shall cause  Serex (in the case of Hologic)  and its
permitted  assigns and  sublicensees (in the case of either party) to commit not
to at any time for a period of seven (7) years following the termination of this
Agreement,  disclose or otherwise  make known or available to any person,  firm,
corporation,  or other entity other than Discloser any Confidential  Information
received from the other party without the express prior written  consent of that
other  party.  With respect to  Confidential  Information  developed  under this
Agreement and which is not Confidential  Information of one party only,  neither
party shall disclose or otherwise make such  Confidential  Information  known or
available to any person, firm, corporation,  or other entity without the express
prior written  consent of the other party,  not to be  unreasonably  withheld or
delayed. Recipient shall utilize reasonable procedures to safeguard Confidential
Information,   including  releasing  Confidential   Information  only  to  those
employees to whom  disclosure is necessary or  appropriate  for the Recipient to

<PAGE>

undertake  its  responsibility  pursuant  to  this  Agreement.  Nothing  in this
Agreement shall prevent  Recipient from disclosing  Confidential  Information to
government agencies for regulatory purposes.

                  10.1   RECIPIENT'S  OWN  USE  OF   CONFIDENTIAL   INFORMATION.
Recipient shall not make any use,  directly or indirectly,  of any  Confidential
Information  of the other  party  except  in the  ordinary  course  of  business
pursuant to this Agreement or any other specific, written agreement entered into
between Ostex and Hologic.

                  10.2 SPECIFIC  PERFORMANCE.  The parties acknowledge that: (a)
the  covenants  set forth in this  SECTION 10 are  essential  to the  activities
contemplated  by this  Agreement;  (b) but for the  agreement  of each  party to
comply  with  such  covenants,  neither  party  would  have  entered  into  such
activities;  (c) each party has  consulted  with or has had the  opportunity  to
consult  with  counsel  and has been  advised  in all  respects  concerning  the
reasonableness of such covenants as to time and scope; (d) Discloser may have no
adequate  remedy at law if  Recipient  violates  or fails to perform  under this
SECTION  10; and (e)  Discloser  shall have the right,  in addition to any other
rights it may have, to seek from a court of competent  jurisdiction  preliminary
and permanent  injunctive  relief to restrain any breach or threatened breach or
otherwise to specifically enforce Recipient's  obligations under this SECTION 10
if Recipient fails to perform in accordance herewith.

         11. SEREX DEVELOPMENT OF PLP TEST. Both parties  acknowledge that Serex
has developed the PLP Assay,  which  determines  the levels of a peptide  linked
pyridinoline resulting from bone resorption,  under the Hologic/Serex Agreement.
Notwithstanding  any other  provision of this  Agreement,  nothing shall prevent
Serex and/or Hologic from  continuing  this  development or  commercializing  or
selling any results thereof, or from using any information provided or gained as
a result of this Agreement, or any derivative thereof,  including Ostex Know-How
and Confidential Information,  in the course of these activities,  provided that
Hologic and Serex otherwise  comply with the  requirements of SECTION 10 hereof,
and provided always that Serex and Hologic shall not be entitled to use for said
purposes any intellectual  property received  pursuant to Hologic's  election to
manufacture of Critical Reagents pursuant to SECTION 2.2 hereof.  This provision
shall not be  construed  to  provide  Hologic or Serex with any right to use any
Ostex  Patent  Rights  for  any  purpose  not  specifically  permitted  by  this
Agreement, or to extend any Ostex Intellectual Property to cover the PLP Assay.

         12.      TERM AND TERMINATION.

                  12.1 INITIAL LICENSE TERM,  AUTOMATIC RENEWAL.  This Agreement
shall be in full force and effect as of the date  first  written  above and
shall remain in effect  XXXXXXXXXXXXthereafter unless sooner terminated pursuant
to this  Section  12. On the XXXXXX  and  subsequent  anniversaries  of the date
hereof,  the term of this  Agreement  shall  (subject to SECTION  12.5 below) be
automatically  continued  for a period  of  XXXXXXXXXXXXXXXXXXX,  unless  either
Hologic  delivers to Ostex,  or Ostex delivers to Hologic,  at least ninety (90)
days prior to such anniversary date, a written

<PAGE>

notice of its intent to  disengage  for cause  based upon  failure of such other
party to use  commercially  reasonable  efforts toward the achievement of market
objectives  for NTx Meter  Systems,  in light of  factors  to  include,  without
limitation, profits, sales volume, market development, and the capture of market
share. In such event, if the parties are unable through good-faith  negotiations
to agree to terms and conditions for further extension of the term hereof,  this
Agreement and all license rights  granted  hereunder  shall  terminate as of the
anniversary  date to which the notice of intent to  disengage  applies,  without
liability of either party to the other in consequence of such termination.

                  12.2  TERMINATION  BY  OSTEX.  Ostex  shall  have the right to
terminate this Agreement  immediately upon notice in the event that: (a) Hologic
fails to  complete  development  of the NTx Meter or to cause  Serex to complete
development of the NTx Meter Strip in accord with the  specifications set out in
ATTACHMENT 7.2.4 XXXXXXXXXXXXXXXXXXXXXXXXX  XXXXXXXXXXX, or to obtain regulatory
approval       therefor       for      the      United       States       within
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX;  or (b) Hologic materially breaches or fails
to  perform  in a  timely  manner  any of its  material  duties  or  obligations
hereunder, and such breach shall remain uncured, or the failure to perform shall
continue,  for at least  sixty  (60) days after  Ostex has given  notice of such
breach or failure. Without limiting the generality of the foregoing, a "material
breach" or "failure to perform" shall include without limitation, any failure to
remit payments,  or failure to comply with any financial reporting  requirement,
or  failure  to  maintain   Hologic's  rights  pursuant  to  the   Hologic/Serex
Agreement..

                  12.3  TERMINATION BY HOLOGIC.  Hologic shall have the right to
terminate this Agreement  immediately  upon notice in the event that (a) Hologic
fails to  complete  development  of the NTx Meter or to cause  Serex to complete
development of the NTx Meter Strip in accord with the  specifications set out in
ATTACHMENT 7.2.4  XXXXXXXXXXXXXXXXXXXXXXXXX  XXXXXXXX,  or to obtain  regulatory
approval     therefor     for    the     United     States     within     XXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  for any  reason  other  than as a  result  of
Hologic's material breach of its obligations under this Agreement;  or (b) Ostex
has  materially  breached  or failed to  perform  in a timely  manner any of its
material duties or obligations hereunder,  and such breach shall remain uncured,
or the  failure to perform  shall  continue,  for at least sixty (60) days after
Hologic has given  notice of such breach or failure to Ostex.  Without  limiting
the  generality of the  foregoing,  a "material  breach" or "failure to perform"
shall include without limitation,  any failure to remit payments,  or failure to
comply with any financial reporting requirement,  or failure to maintain Ostex's
rights pursuant to the WRF/Ostex Exclusive License Agreement.

                  12.4     TERMINATION FOR TECHNICAL DEFECT.

                           12.4.1   BY OSTEX.  If within ninety (90) days of 
the Effective Date,  Ostex  determines
that a material  technical  deficiency exists in the SARA Format which is likely
to prevent Serex or Hologic from  completing  development  of an NTx Meter Strip
which meets the Product Specifications  described in ATTACHMENT 7.2.4 within the
time  period set out in SECTION  12.2(A)  above,  Ostex  shall  provide a notice
thereof to Hologic which  describes in detail said purported  deficiency and the

<PAGE>

impact thereof on the  specifications  and/or time frame for  development.  Upon
receipt of such notice,  Hologic  shall  conduct a though  review of the subject
matter of said  notice,  provide  to Ostex a detailed  report of how  Hologic or
Serex plan to resolve the issues raised and to meet the relevant  specifications
and/or time frame,  and meet with Ostex to review said report.  If Hologic fails
to provide said report within  fifteen (15) business days  following  receipt of
such notice,  Ostex may within ten business days following the final due date of
such report,  terminate this Agreement upon written notice without  liability of
any sort.

                           12.4.2   BY  HOLOGIC.  If  within  ninety  (90)  
days  of the  Effective  Date,  Hologic
determines  that  a  material  technical  deficiency  exists  in the  NTx  Assay
Technology or Critical Reagents which is likely to prevent Serex or Hologic from
completing   development   of  an  NTx  Meter  Strip  which  meets  the  Product
Specifications  described in ATTACHMENT  7.2.4 within the time period set out in
SECTION  12.2(A)  above,  Hologic shall provide a notice  thereof to Ostex which
describes  in detail said  purported  deficiency  and the impact  thereof on the
specifications  and/or time frame for development.  Upon receipt of such notice,
Ostex  shall  conduct a though  review  of the  subject  matter of said  notice,
provide to Hologic a detailed  report of how Ostex  plans to resolve  the issues
raised and to meet the relevant  specifications and/or time frame, and meet with
Hologic to review  said  report.  If Ostex fails to provide  said report  within
fifteen (15) business days following receipt of such notice,  Hologic may within
ten business days  following the final due date of such report,  terminate  this
Agreement upon written notice without liability of any sort.

                  12.4     BANKRUPTCY OF A PARTY.

                           12.4.1   OSTEX  BANKRUPTCY.  All rights and licenses
  granted  under or pursuant to this
Agreement  by Ostex to Hologic  are,  and shall  otherwise  be deemed to be, for
purpose  of  Section  365(n) of Title 11,  U.S.  Code (the  "Bankruptcy  Code"),
licenses of rights to  "intellectual  property" as defined under Section 101(60)
of the Bankruptcy  Code.  The parties agree that Hologic,  as a licensee of such
rights  under this  Agreement,  shall  retain and may fully  exercise all of its
rights and elections under the Bankruptcy Code.

                           12.4.2   HOLOGIC  BANKRUPTCY.  All rights and
licenses granted under or pursuant to this
Agreement  by  Hologic to Ostex are,  and shall  otherwise  be deemed to be, for
purpose  of  Section  365(n) of Title 11,  U.S.  Code (the  "Bankruptcy  Code"),
licenses of rights to  "intellectual  property" as defined under Section 101(60)
of the  Bankruptcy  Code.  The parties  agree that Ostex,  as a licensee of such
rights  under this  Agreement,  shall  retain and may fully  exercise all of its
rights and elections under the Bankruptcy Code.

                  12.5     RESERVED

                  12.6  MAXIMUM  TERM.  Notwithstanding  any  provision  of this
Agreement to the contrary,  the license granted with respect to the Ostex Patent
Rights  under  SECTION  2 above  shall  terminate  upon  expiration  of the last
remaining Ostex Patent Right.  Upon such expiration,  Hologic shall be deemed to
have a perpetual,  worldwide,  royalty free license to  manufacture,  make, have
manufactured  or made,  use,  market,  sell,  and  distribute  NTx Meter  Strips
worldwide except Japan for any application.


<PAGE>

                  12.7     RIGHTS AND DUTIES UPON TERMINATION.

                           12.7.1   PAYMENTS.  Upon  termination  of this  
agreement,  each party  shall pay to the other all payments that are due 
and have accrued and are outstanding as of the date of termination.

                           12.7.2   RETURN OF MATERIALS.  Within  thirty (30) 
days  following  termination  of this
Agreement,  each party having  possession  of or control  over any  Confidential
Information  of the other party shall return to such other party all written and
otherwise  recorded or stored matter containing such  Confidential  Information,
including all original matter and all copies thereof;  provided,  however,  that
each  party's  legal  department  or outside  counsel may retain one copy of the
Confidential Information in its confidentially  maintained files, solely for the
purpose of identifying  information  to be protected  pursuant to any applicable
non-disclosure obligation.

                           12.7.3   NTX METER STRIPS REMAINING.  Upon 
termination of this Agreement,  Hologic shall
have the right to sell NTx Meter Strips then  remaining in its  possession or to
be manufactured  using Critical  Reagents then held in inventory,  and Ostex may
sell NTx Meter Strips then remaining in its possession, within a reasonable time
after  termination  hereof;  provided,  however,  that all such  Sales  shall be
subject  to  the  royalty   provisions   of  this   Agreement,   notwithstanding
termination.  Alternatively,  Hologic may return Critical Reagents  remaining in
inventory and in good  condition to Ostex for a refund of the original  transfer
price (or for credit toward any amounts due).

                           12.7.4   SURVIVAL  OF  TERMS.   Notwithstanding   
any  other  provision  herein  to  the
contrary, SECTIONS 3.4, 7.2.4, 7.3, 7.4, 7.6-7.8, 8-13, 16.4, 16.5, and 18-28 of
this Agreement shall survive any termination or expiration hereof.

         13.      REPRESENTATIONS, WARRANTIES AND INDEMNITIES.

                  13.1     BY OSTEX.  Ostex represents and warrants to Hologic 
as follows:
                           13.1.1   ORGANIZATION  AND AUTHORITY.  As of the 
Effective Date of the Agreement,  Ostex
is a corporation duly organized, validly existing and in good standing under the
laws of the State of  Washington,  USA, has all  requisite  corporate  power and
authority to carry on its business and perform its obligations hereunder, and is
duly qualified to do business in any of those jurisdictions in the United States
of America where failure to qualify could have a material  adverse effect on its
ability to perform its obligations hereunder. The execution and delivery of this
Agreement by Ostex, and the performance of the obligations of Ostex contemplated
hereby,  have been duly and validly  authorized by all necessary legal action on
its part,  and this  Agreement  is legal,  valid and  binding  against  Ostex in
accordance with its terms.  Except as have been or will be obtained by Ostex, no
permit, consent, approval or authorization of, or declaration to or filing with,
any person,  party or governmental or regulatory  authority of the United States
is required in connection with the delivery,  consummation and/or performance by

<PAGE>

Ostex of this Agreement. As of the Effective Date of the Agreement,  Ostex is in
full compliance with the WRF/Ostex  Exclusive License Agreement and has not been
notified  of any  assertion  that it is in default of said  WRF/Ostex  Exclusive
License  Agreement or that WRF plans to terminate  any Ostex rights  thereunder.
Ostex shall  immediately  notify Hologic if it receives any notice that it is in
default  of said  WRF/Ostex  Exclusive  License  Agreement  or that WRF plans to
terminate any Ostex right thereunder.

                           13.1.2   OSTEX  PATENT  RIGHTS  AND  OSTEX  KNOW-HOW.
  As of the  Effective  Date of the
Agreement,  and except as described in ATTACHMENT 13.1.2 to this Agreement,  (a)
Ostex has sole and  exclusive  rights to the Ostex Patent  Rights and all rights
necessary  to convey Ostex  Know-How to Hologic and Serex;  (b) the Ostex Patent
Rights,  to the best  knowledge of Ostex are valid and  enforceable,  and do not
infringe on the proprietary rights of any third party: (c) Ostex is not aware of
any "prior art" or other claim  which  would  invalidate  any part or all of the
Ostex Patent Rights; or any claim that Ostex does not have all rights to use and
permit Hologic and Serex to use the Ostex Know-How for all purposes permitted by
this Agreement; (d) Ostex is not aware of any unexpired patent or pending patent
application  of a party not a party to this  agreement  which has  claims  which
cover any part of the Ostex Know-How or Ostex Patent  Rights;  and (e) Ostex has
taken all  necessary  actions to maintain all Ostex Patent  Rights in full force
and effect.

                           13.1.3   NO DEFAULT.  The  execution,  delivery  and
  performance  of this  Agreement by
Ostex does not and shall not conflict with, result in a breach of, or constitute
a default  under (with or without the giving of notice,  or the passage of time,
or both),  any  agreement or instrument to which Ostex is a party or by which it
is bound.

                           13.1.4   OSTEX'S   DISCLAIMER  OF  OTHER  
 WARRANTIES.   Ostex   disclaims  all  implied
warranties, including without limitation any warranty of merchantability or
 fitness for a particular purpose.

EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT,  OSTEX MAKES NO REPRESENTATIONS
AND EXTENDS NO WARRANTIES OF ANY KIND,  EITHER EXPRESS OR IMPLIED,  INCLUDING NO
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

                  13.2     BY HOLOGIC.  Hologic represents and warrants to Ostex
 as follows:

                           13.2.1   ORGANIZATION  AND  AUTHORITY.  As of  the  
Effective  Date  of  the  Agreement,
Hologic is duly organized,  validly existing and in good standing under the laws
of Delaware,  USA has all requisite power and authority to carry on its business
and the  performance of its obligations  hereunder,  and is duly qualified to do
business in any of those  jurisdictions  where  failure to qualify  could have a
material adverse effect on its ability to perform its obligations hereunder. The
execution and delivery of this Agreement by Hologic,  and the performance of the
obligations  contemplated  hereby,  have been duly and validly authorized by all
necessary  legal  action on its part,  and this  Agreement  is legal,  valid and
binding  against  Hologic in accordance  with its terms.  Except as have been or
will be obtained by Hologic, no permit,  consent,  approval or authorization of,

<PAGE>

or  declaration  to or  filing  with,  any  person,  party  or  governmental  or
regulatory  authority  having  jurisdiction  is required in connection  with the
delivery,  consummation and/or performance of this Agreement As of the Effective
Date of the  Agreement,  Hologic is in full  compliance  with the  Hologic/Serex
Agreement and has not been  notified of any  assertion  that it is in default of
said Hologic/Serex Agreement or that Serex plans to terminate any Hologic rights
thereunder.  Hologic  shall  immediately  notify Ostex if it receives any notice
that it is in default of said  Hologic/Serex  Agreement  or that Serex  plans to
terminate any Hologic right thereunder.

                           13.2.2   SEREX PATENT RIGHTS.  As of the Effective  
Date of the  Agreement,  (a) Hologic
is not aware of any "prior  art" which would  invalidate  any part or all of the
SARA patents;  and (b) Hologic is not aware of any  unexpired  patent or pending
patent  application  of a party not a party to this  agreement  which has claims
which cover any part of the SARA patents.

                                    13.2.2.1HOLOGIC  PATENT RIGHTS AND HOLOGIC 
 KNOW-HOW.  As of the Effective Date
of the  Agreement,  (a)  Hologic  has sole and  exclusive  rights to the Hologic
Patent Rights and all rights  necessary to convey Hologic Know-How to Ostex; (b)
the  Hologic  Patent  Rights,  to the best  knowledge  of Hologic  are valid and
enforceable,  and do not infringe on the proprietary  rights of any third party;
(c)  Hologic  is not  aware  of any  "prior  art" or  other  claim  which  would
invalidate  any part or all of the  Hologic  Patent  Rights;  or any claim  that
Hologic  does not have all  rights to use and  permit  Ostex to use the  Hologic
Know-How for all purposes permitted by this Agreement;  (d) Hologic is not aware
of any unexpired patent or pending patent  application of a party not a party to
this Agreement which has claims which cover any part of the Hologic  Know-How or
Hologic  Patent  Rights;  and (e)  Hologic  has taken all  necessary  actions to
maintain all Hologic Patent Rights in full force and effect.

                           13.2.3   NO DEFAULT.  The  execution,  delivery  and
  performance  of this  Agreement by
Hologic  does not and  shall  not  conflict  with,  result  in a breach  of,  or
constitute a default under (with or without the giving of notice, or the passage
of time, or both), any agreement or instrument to which Hologic is a party or by
which it is bound.

                           13.2.4   HOLOGIC'S  DISCLAIMER  OF  OTHER  
WARRANTIES.  Hologic  disclaims  all  implied
warranties, including without limitation any warranty of merchantability or 
fitness for a particular purpose.
EXCEPT  AS   EXPRESSLY   SET  FORTH  IN  THIS   AGREEMENT,   HOLOGIC   MAKES  NO
REPRESENTATIONS  AND  EXTENDS  NO  WARRANTIES  OF ANY KIND,  EITHER  EXPRESS  OR
IMPLIED,  INCLUDING NO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE

                  13.3 U.S.  FOREIGN  CORRUPT  PRACTICES  ACT.  Each party shall
indemnify, defend and hold the other party, its subsidiaries and Affiliates, and
the directors,  officers, employees and agents of any of them, harmless from and
against all and any claims,  proceedings,  losses,  fines,  expenses  (including
without  limitation  reasonable  attorneys  fees  and  expenses)  and  penalties

<PAGE>

incurred by said party arising out of any Prohibited  Practice committed by said
party or any of its officers, directors, shareholders, employees, or agents.

For purposes of this  SECTION 13, the  following  shall be deemed a  "Prohibited
Practice": the offer, payment, promise to pay, or authorization of the paying of
any money, or the offer, giving,  promise to give or authorization of the giving
of  anything  of value to any  officer  or  employee  of any  government  or any
department,  agency  or  instrumentality  thereof,  or any  person  acting in an
official capacity for or on behalf of any such government, department, agency or
instrumentality,  or any political party or official  thereof,  or any candidate
for political office, or any intermediary for any such persons or party, in each
case for purposes of (a)  influencing any act or decision of any such persons or
party in their or its  official  capacity,  or (b)  inducing  any such person or
party to do or omit to do any act in violation of the lawful duty of such person
or party, or (c) inducing any such person or party to use their or its influence
with any government or instrumentality thereof to affect or influence any act or
decision of any such  government or  instrumentality,  in each case (a), (b) and
(c) in order to assist the  applicable  party  hereto in  obtaining or retaining
business for, or with, or directing business to, any person or entity

                  13.4  GOVERNMENTAL  COMPLIANCE.  Each party  shall  obtain and
maintain all required licenses, permits,  certificates and authorizations needed
to perform its obligations under this Agreement,  including  without  limitation
those   required  for  said  party's   appointment  as   sublicensee,   for  the
effectiveness of this Agreement in all jurisdictions  where said party operates,
for the import and for the export of NTx Meter  Systems,  and for the marketing,
distribution  and  Sale  of NTx  Meter  Systems.  Each  party  shall  be  solely
responsible  for compliance  with any foreign  exchange  controls  affecting its
activities.

         14.      THIRD-PARTY INFRINGEMENT.

                  14.1 NOTICE OF THIRD-PARTY  INFRINGEMENT.  If, during the term
of this Agreement, either party becomes aware that one or more third parties are
infringing or are  threatening to infringe the Patent Rights of a party licensed
hereunder relating to the Field of Use, said party (the "Notifying Party") shall
immediately  report such  information  to the other party to this  Agreement and
shall provide in such report all details in said party's knowledge or possession
concerning the kind and character of the  infringement  and any other  pertinent
information  that  said  party may  have.  At such  time as the party  owning or
controlling  the  infringed  patents  ("Aggrieved  Party")  shall,  in its  sole
judgment,   be  satisfied   that  there  exists  a  reasonable   likelihood   of
infringement,  Aggrieved Party shall take such steps, including notification, to
place the putative  infringer on notice of Aggrieved Party's claims. The form of
the  notification  and the  manner  and  nature  of any  communications  between
Aggrieved Party and the alleged infringer shall be within the sole discretion of
Aggrieved Party.

                  14.2 RIGHT TO SUE. If, sixty (60) days after receipt of notice
of a perceived third-party infringement, such third party infringement continues
and the  Aggrieved  Party has not  commenced  legal  action or  presented to the

<PAGE>

Notifying  Party a plan acceptable to the Notifying Party to enjoin or otherwise
to resolve such infringement, then the Notifying Party shall be entitled, at its
own expense and for its own benefit,  to commence an action in its own name.  In
the event that the Aggrieved  Party  initiates such action,  the Aggrieved Party
shall be entitled to retain all damages awarded  therein.  In the event that the
Notifying Party initiates such action,  the Notifying Party shall be entitled to
retain one half of all damages awarded therein attributable to the Field of Use,
after payment of all reasonable legal expenses of such litigation.  In the event
that the rules  then  obtaining  shall  require  the naming of the owner of said
Patent Rights for purposes of such  infringement  action,  the  Notifying  Party
shall be entitled to name the Aggrieved  Party,  or to cause the Aggrieved Party
to consent to be named,  as a party  plaintiff in such action;  and failing such
cooperation the Notifying Party shall be entitled to reduce royalties payable to
the Aggrieved  Party by fifty percent  (50%).  Each party shall assist the other
party and reasonably cooperate in any such action at said party's request.

         15.      DEFENSE OF THIRD-PARTY CLAIMS.

                  15.1 HOLOGIC DEFENSE OF THIRD-PARTY  CLAIMS AND INDEMNITY.  In
the event that any claim,  suit,  or other legal  proceeding  is  threatened  or
commenced  against  Ostex or WRF  that is  founded,  in whole or in part,  on an
allegation  that the NTx Meter or NTx Meter Strip  infringes  any trade  secret,
patent,  or copyright  belonging  to a third party (other than WRF),  Ostex will
give Hologic  prompt  written  notice of such legal  proceeding  and Hologic may
elect to assume sole control of the defense to or  settlement  of such  dispute.
Ostex  shall  cooperate  fully  with  Hologic  in  any  defense,  settlement  or
compromise made by Hologic.  Ostex shall not enter into any settlement agreement
or other voluntary resolution of any such claim, suit, or other legal proceeding
without obtaining Hologic's prior written consent thereto. If Ostex has complied
fully with the procedures set forth in this SECTION 15.1, Hologic will indemnify
and hold Ostex  harmless  from and  against  any loss,  cost,  damage,  or other
expenses  incurred by Ostex as a result of such claim, suit or legal proceeding.
If a final  injunction is obtained  against  Ostex's use of the NTx Meter or NTx
Meter Strips, or if in the opinion of Hologic the subject NTx Meter or NTx Meter
Strips are likely to become the subject of a successful  claim of  infringement,
Hologic  may,  at its option and  expense,  (i)  procure  for Ostex the right to
continue  distributing  and/or  using the NTx Meter or NTx  Meter  Strips,  (ii)
replace  or modify  the NTx Meter or NTx Meter  Strips so that it (they)  become
non-infringing, or (iii) if neither (i) or (ii) are reasonably available, accept
return of the NTx Meter or NTx Meter  Strips held by Ostex and its  distributors
in  inventory,  and  terminate  this  Agreement  without  further  obligation or
liability.  This  indemnification  provision  shall be null and void and Hologic
shall have no  liability to the extent that any claim is based on any use of the
NTx Assay Technology, Critical Reagents or Ostex Intellectual Property or if the
NTx Meter or NTx Meter  Strips have been  modified  or tampered  with in any way
without the express written consent of Hologic,  or if Ostex has any interest in
the  claim,  suit or other  legal  proceeding,  or any  license  to any right so
asserted.

                  15.2 OSTEX DEFENSE OF THIRD-PARTY CLAIMS AND INDEMNITY. In the
event that any claim, suit, or other legal proceeding is threatened or commenced
against Hologic or Serex that is founded,  in whole or in part, on an allegation
that the NTx Assay Technology,  Critical Reagents or Ostex Intellectual Property
as used in the NTx Meter System infringes any trade secret, patent, or copyright

<PAGE>

belonging to a third party  (other than  Serex),  Hologic will give Ostex prompt
written  notice of such  legal  proceeding  and  Ostex may elect to assume  sole
control of the defense to or settlement of such dispute. Hologic shall cooperate
fully with Ostex in any defense, settlement or compromise made by Ostex. Hologic
shall not enter into any settlement  agreement or other voluntary  resolution of
any such claim,  suit, or other legal proceeding without obtaining Ostex's prior
written consent  thereto.  If Hologic has complied fully with the procedures set
forth in this SECTION 15.2,  Ostex will indemnify and hold Hologic harmless from
and against any loss, cost,  damage,  or other expenses incurred by Hologic as a
result  of such  claim,  suit or  legal  proceeding.  If a final  injunction  is
obtained against Hologic's use of the NTx Assay Technology, Critical Reagents or
Ostex  Intellectual  Property  as used in the NTx  Meter  Systems,  or if in the
opinion  of  Ostex  the  NTx  Assay  Technology,   Critical  Reagents  or  Ostex
Intellectual  Property are likely to become the subject of a successful claim of
infringement,  Ostex may, at its option and expense, (i) procure for Hologic the
right to continue  distributing and/or using the NTx Assay Technology,  Critical
Reagents or Ostex Intellectual Property in the NTx Meter System, (ii) replace or
modify  the NTx  Assay  Technology,  Critical  Reagents  or  Ostex  Intellectual
Property  so that it (they)  become  non-infringing,  or (iii) if neither (i) or
(ii) are  reasonably  available,  accept  return  of the NTx  Assay  Technology,
Critical Reagents or Ostex  Intellectual  Property used in the NTx Meter Systems
held by Hologic and its distributors in inventory,  and terminate this Agreement
without further obligation or liability. This indemnification provision shall be
null and void and Ostex  shall have no  liability  to the extent  that NTx Assay
Technology,  Critical Reagents or Ostex Intellectual Property have been modified
or tampered with in any way without the express  written consent of Ostex, or if
Hologic or Serex have any interest in the claim, suit or other legal proceeding,
or any license to any right so asserted.

                  15.3  ROYALTY   PAYMENTS.   Except  as  provided  above,   any
entitlement to terminate royalties shall occur only upon a final adjudication of
the invalidity or non-enforceability of the patents, copyrights or trade secrets
in question. For such purposes, final adjudication shall mean an adjudication or
determination  by a trial  court or a court of  appeal,  which  adjudication  or
determination shall be final, binding and not further appealable, whether by its
terms or by the passage of time.

         16.      USE OF TRADEMARKS AND TRADE NAMES.

                  16.1 RESTRICTED  RIGHTS TO USE. No provision of this Agreement
shall be interpreted  or construed as conferring  upon either party any right to
use in labeling, advertising,  marketing, publicizing or otherwise promoting NTx
Meter  Systems,  any name,  trade  name,  trademark,  or other  designation  (or
derivation  thereof)  of the  other  party  hereto or WRF or the  University  of
Washington, or Serex, except as expressly provided under this SECTION 16.

                  16.2 USE OF NAMES  AND  MARKS  IN  LABELING.  As a part of the
marketing plan prepared pursuant to SECTION 6.2 hereof,  the parties shall agree
upon  appropriate  trademark(s)  to be used in connection  with NTx Meter Strips
marketed,  promoted,  sold,  and/or  distributed  under this  Agreement.  In the

<PAGE>

absence of such  agreement,  the parties  agree that Hologic  shall affix to the
outer  packaging of, and shall include on the package  insert for, any NTx Meter
Strips  marketed,  promoted,  sold,  and/or  distributed  by Hologic  under this
Agreement,  and in addition to its own trademarks and names,  one or more labels
displaying  with equal  prominence  to said  Hologic  trademarks  or names,  the
statement "An  OsteomarkAE  Assay" or such other trademark or statement as Ostex
shall reasonably  request,  and Ostex shall affix to the outer packaging of, and
shall  include  on the  package  insert  for,  any NTx  Meter  Strips  marketed,
promoted,  sold,  and/or  distributed  by Ostex  under  this  Agreement,  and in
addition to its own trademarks and names,  displaying  with equal  prominence to
said Ostex  trademarks  or names such other  trademark  or  statement as Hologic
shall reasonably request.  Ostex shall also have the right to review and approve
all claims relating to the intended use of NTx Meter Strips contained in package
inserts  and  other   promotional   materials,   which  approval  shall  not  be
unreasonably   withheld.   Each  party  hereby  grants  to  the  other  party  a
non-transferable,  non-exclusive  license,  concurrent  with  the  term  of this
Agreement,   to  use  such  statement  and/or   trademark   accordingly  and  in
substantially the same manner as used by its owner; provided, however, that each
such use of such statement  and/or  trademark be accompanied by a printed notice
identifying  the  owner  as the  owner  thereof.  Neither  party  shall  use any
trademark  of the other  party with  respect  to  products  not  covered by this
Agreement.  In the  event  that  particular  NTx  Meter  Strips  do not meet the
specifications or quality standards  required under SECTIONS 3.4 or 7.2.4 above,
either  party may cause the other party to remove all  trademarks  of said party
from such NTx Meter  Strips  and shall  have the right to cancel  the  foregoing
grant of license to use such  trademarks,  unless the other party promptly meets
such  specifications  or quality  standards.  Each party shall have the right to
receive  and approve the use of its marks in any  proposed  product  literature,
advertising  material or material for publication.  In all such materials unless
otherwise  specifically agreed in advance in writing, the immunoassay  performed
by the NTx Meter Strips shall be identified as "An OsteomarkAE Assay."

                  16.3 TRADEMARK  REGISTRATION.  Ostex and Hologic shall each be
responsible  for  the   registration,   maintenance  and  enforcement  of  their
respective  names,  trade names, and trademarks;  provided,  however,  that each
party  shall  aid the  other  in the  enforcement  of  that  party's  rights  by
monitoring for, and notifying said party of, any unauthorized use of any of said
party's  trademarks.  Each party shall from time to time,  and in any event upon
the  issuance  of  additional  registrations,  modify its use of  trademarks  to
incorporate  proper  notice  of  registration  and other  claims  of  right,  in
accordance  with the laws  and  customs  of the  various  countries  in which it
operates pursuant to this Agreement.

                  16.4 OSTEX  REPRESENTATIONS  AND WARRANTIES.  Ostex represents
and warrants, as of the date of this Agreement, that: (a) Ostex is the owner and
registrant of the  trademarks  issued  registrations  as indicated by ATTACHMENT
16.4;  (b)  Ostex is named as  applicant  in  those  applications  indicated  by
ATTACHMENT  16.4 as pending;  and (c) to the best of its knowledge,  none of the
Ostex trademarks infringes upon the trademark,  trade name, or other proprietary
rights of a third party. In the event that any action or proceeding is initiated
against  Ostex,  Hologic,  or any other  licensee or distributor of Ostex in any
country alleging that the trademark  "Osteomark"  infringes the trademark rights
of the third party initiating such action or proceeding, Hologic may continue to
market NTx Meter Strips within such country  without the  trademark  "Osteomark"
affixed thereto (but with such other trademark as Ostex may reasonably  specify)
pending resolution of the dispute as to trademark rights.


<PAGE>

                  16.5   HOLOGIC   REPRESENTATIONS   AND   WARRANTIES.   Hologic
represents and warrants, as of the date of this Agreement,  that: (a) Hologic is
the owner and registrant of the trademarks issued  registrations as indicated by
ATTACHMENT  16.5;  (b)  Hologic  is named  as  applicant  in those  applications
indicated by ATTACHMENT  16.5 as pending;  and (c) to the best of its knowledge,
none of the Hologic  trademarks  infringes  upon the  trademark,  trade name, or
other  proprietary  rights of an third  party.  In the event  that any action or
proceeding  is  initiated  against  Hologic,  Ostex,  or any other  licensee  or
distributor  of Hologic  in any  country  alleging  that any  Hologic  trademark
infringes  the  trademark  rights of the third party  initiating  such action or
proceeding,  Ostex may continue to market NTx Meter  Strips  within such country
without said Hologic trademark affixed thereto (but with such other trademark as
Hologic  may  reasonably  specify)  pending  resolution  of  the  dispute  as to
trademark rights.

         17.      ASSIGNMENT AND SUBLICENSE.

                  17.1 BY  HOLOGIC.  Except as  specifically  permitted  by this
Agreement,  Hologic  shall not  assign,  sublicense,  delegate,  or in any other
manner transfer any of its rights, privileges,  obligations or duties under this
Agreement to any non-Affiliate  third party without the prior written consent of
Ostex,  which  consent may be withheld in Ostex's sole and absolute  discretion,
provided that this provision  shall not apply to any merger,  consolidation,  or
sale  of  substantially  all of  the  assets  of  Hologic,  or  any  third-party
acquisition of a majority of the business interests or voting shares of Hologic,
provided that the surviving party shall within a reasonable period following the
final  closing of such  transaction,  expressly  agree in writing to be bound by
this  agreement.  Any  attempt by Hologic to  assign,  sublicense,  delegate  or
otherwise transfer any right, privilege, obligation or duty under this Agreement
other than in  accordance  with this SECTION 17 shall be void and shall,  at the
option of Ostex,  be cause for immediate  termination  of this Agreement and all
licenses granted  hereunder.  Transfers of any rights hereunder by Hologic to an
Affiliate  shall be  permitted  only after the  delivery to Ostex of  reasonable
evidence  that such  Affiliate has agreed in writing to be bound by the terms of
this Agreement.

                  17.2  BY  OSTEX.  Except  as  specifically  permitted  by this
Agreement, Ostex shall not assign, sublicense,  delegate, or in any other manner
transfer  any of its  rights,  privileges,  obligations  or  duties  under  this
Agreement to any non-Affiliate  third party without the prior written consent of
Hologic,   which  consent  may  be  withheld  in  Hologic's  sole  and  absolute
discretion,  provided  that  this  provision  shall  not  apply  to any  merger,
consolidation,  or sale of  substantially  all of the  assets of  Ostex,  or any
third-party acquisition of a majority of the business interests or voting shares
of Ostex,  provided  that the surviving  party shall within a reasonable  period
following the final closing of such  transaction,  expressly agree in writing to
be bound by this agreement. Any attempt by Ostex to assign, sublicense, delegate
or  otherwise  transfer  any  right,  privilege,  obligation  or duty under this
Agreement other than in accordance with this SECTION 17 shall be void and shall,
at the option of Hologic,  be cause for immediate  termination of this Agreement
and all licenses granted  hereunder.  Transfers of any rights hereunder by Ostex
to an  Affiliate  shall be  permitted  only  after the  delivery  to  Hologic of
reasonable evidence that such Affiliate has agreed in writing to be bound by the
terms of this Agreement.


<PAGE>

         18.      ARBITRATION.

                  18.1  AGREEMENT  TO SETTLE  DISPUTES  BY  ARBITRATION.  At the
request  through  notice of either Ostex or Hologic,  any  controversy  or claim
arising  between the parties and related to or arising out of the  construction,
interpretation, or enforcement of any term or condition of this Agreement or any
transaction  hereunder  (including  the decision to enter into this  Agreement),
which  controversy or claim cannot first be settled amicably between the parties
(including  without  limitation  through  utilization of  third-party  mediation
agreed to by both parties), shall be submitted to arbitration.  Such arbitration
shall be  conducted  in Seattle,  Washington,  if  initiated  by Hologic,  or in
Boston,  Massachusetts,  if  initiated  by Ostex,  and in either  case  shall be
conducted in accordance  with the applicable  Rules of the American  Arbitration
Association in effect on the date of such controversy or claim.

                  18.2 APPOINTMENT OF ARBITRATORS. Within thirty (30) days after
the  delivery  pursuant  to  SECTION  18.1  above of a  notice  of  request  for
arbitration, Hologic and Ostex shall each appoint one person as an arbitrator to
hear and  determine  the  dispute.  The two persons so chosen shall by agreement
select  a third,  impartial  arbitrator,  which  selection  shall  be final  and
conclusive  upon  both  parties.   Each  arbitrator   shall  be  experienced  in
international and domestic manufacturing and distribution of products similar to
NTx Meter  Systems.  If either party fails to designate  its  arbitrator  within
sixty (60) days after the notice of arbitration is received, then the arbitrator
designated by the one party shall act as the sole arbitrator and shall be deemed
to be the single, mutually approved arbitrator to resolve the dispute.

                  18.3 ARBITRATORS'  POWERS.  The arbitrators shall have all the
powers  of a State or  Federal  Court  located  at the site of the  arbitration,
including the power to order specific enforcement of this Agreement and to order
the  production  of  relevant  and  non-privileged  documents  by one  party for
inspection and duplication by the other party prior to the arbitration  hearing;
provided,  however,  that the arbitrators  shall be bound by this Agreement with
regard to the restriction on consequential,  incidental, and punitive damages as
set forth in SECTION 19.3 below.

                  18.4  DISCOVERY.  The  arbitrators  prior to the hearing shall
grant  discovery  pursuant  to the  intendment  of the  Federal  Rules  of Civil
Procedure,  and  as  the  arbitrators  determine  to be  appropriate  under  the
circumstances.

                  18.5 PROTECTIVE  ORDER. In the event of arbitration and at the
request of either Ostex or Hologic, in order to protect Confidential Information
and any other  matter  that  either  party  would  normally  not reveal to third
parties,  the  arbitrators  shall enter a  protective  order in such form as the
parties shall stipulate or as the arbitrators shall determine is suitable. Among
other  things,  the  protective  order  shall  stipulate  that  the  arbitrators
themselves  shall  receive  any  information   designated  by  either  party  as
"confidential"  solely for purposes of assessing  the facts and law for purposes
of the arbitration,  and shall not otherwise use or disclose such matter. At the
request of either party,  the  protective  order shall be entered as an award of

<PAGE>

the arbitration  panel and shall enable either party to obtain the assistance of
a court of competent  jurisdiction to enter equitable decrees or other relief to
enforce the provisions of the order as if it had been entered by that court.

                  18.6 EFFECT OF DECISION. The decision of the arbitrators shall
state the reason for the award and shall be final,  binding and conclusive  upon
the parties.  The parties shall comply with such decision in good faith as if it
were a final  decision of a court.  Judgment  upon the award shall be entered in
any court of  competent  jurisdiction.  Any award  made in  connection  with any
arbitration shall be made in U.S. Dollars.

                  18.7 RIGHTS OF THIRD PARTIES. Notwithstanding the agreement to
arbitrate any dispute between Ostex and Hologic, in the event that a controversy
or claim between Ostex and Hologic  involves an  adjudication of the rights of a
third party,  and that third party does not agree to submit to  arbitration  and
would under Rule 19(a) of the Federal Rules of Civil Procedure,  if feasible, be
joined as an  indispensable  party,  then the  dispute  shall be brought to, and
determined by, a court of the competent jurisdiction.

                  18.8 INTERIM  RELIEF.  Upon the application of either party to
this  Agreement,  and  whether or not an  arbitration,  mediation  or attempt to
settle amicably has yet been initiated,  all courts having jurisdiction over one
or more of the  parties are  authorized  to: (i) issue and enforce in any lawful
manner such temporary  restraining  orders,  preliminary  injunctions  and other
interim  measures  of relief as may be  necessary  to prevent  harm to a party's
interests  or  as  otherwise  may  be  appropriate  pending  the  conclusion  of
arbitration  proceedings pursuant to this Agreement;  and (ii) enter and enforce
in any lawful manner such  judgments for  permanent  equitable  relief as may be
necessary  to  prevent  harm  to a  party's  interests  or as  otherwise  may be
appropriate   following  the  issuance  of  arbitral  awards  pursuant  to  this
Agreement.

         19.      ATTACHMENTS.  The  Attachments  listed below are  incorporated
  by reference  into this Agreement
and shall for all purposes be deemed part hereof:

Attachment D               Serex Patent Rights
Attachment 3.4             Ostex Critical Reagent Specifications
Attachment 6.2             Marketing Plan (To be Appended per SECTION 6.2)
Attachment 7.2.4           Product Specifications - NTx Meter Strips and NTx
                           Meters

Attachment 13.1.2          Ostex Patent Rights and Know-How - Exceptions to 
                           Warranty
Attachment 16.4            Ostex Trademark Filings
Attachment 16.5            Hologic Trademark Filings


         20.      PUBLICITY.  No party shall  announce or publicize  this  
     Agreement or any terms thereof  without the advance  written consent of the
others (which approval shall not be unreasonably withheld).


<PAGE>

         21.      RESPONSIBILITY  FOR CLAIMS.  In order to distribute  between 
     themselves  the  responsibility  for the  handling  and  expense  of claims
arising out of the manufacture, distribution, Sale or use of NTx Meter

Systems, the parties agree as follows:

                  21.1  OSTEX  LIABILITY.  Ostex  shall be liable  for and shall
indemnify and hold Hologic harmless  against any liability,  damages or loss and
from  any  claims,  suits,  proceedings,  demands,  recoveries  or  expenses  in
connection with (i) any Critical  Reagents or NTx Assay  Technology  licensed or
sold by  Ostex to  Hologic  or its  designated  manufacturers  pursuant  to this
Agreement  arising out of, based on, or caused by product claims whether written
or oral,  made or alleged to be made,  by Ostex in its  advertising,  publicity,
promotion,  or Sale of the Critical  Reagents or NTx Assay Technology where such
product  claims  were not  approved  by Hologic,  including  without  limitation
expenses of total or partial product recalls as described in SECTION 7.7 hereof,
or  (ii)  any  breach  by  Ostex  of any of its  representations  or  warranties
contained  herein or (iii) any of its  negligent or willful  acts or  omissions.
Hologic shall  promptly  notify Ostex of any such demand or claim which comes to
its attention.

                  21.2 HOLOGIC LIABILITY.  Hologic shall be liable for and shall
indemnify and hold Ostex  harmless  against any  liability,  damages or loss and
from  any  claims,  suits,  proceedings,  demands,  recoveries  or  expenses  in
connection  with (i) any NTx Meters or NTx Meter Strips sold by Hologic to Ostex
pursuant to this Agreement arising out of, based on, or caused by product claims
whether  written  or  oral,  made or  alleged  to be  made,  by  Hologic  in its
advertising, publicity, promotion, or Sale of the NTx Meters or NTx Meter Strips
where  such  product  claims  were not  approved  by  Ostex,  including  without
limitation  expenses of total or partial product recalls as described in SECTION
7.7  hereof,  or (ii) any  breach by Hologic  of any of its  representations  or
warranties  contained  herein or (iii) any of its  negligent  or willful acts or
omissions. Ostex shall promptly notify Hologic of any such demand or claim which
comes to its attention.

                  21.3   CONSEQUENTIAL,   INCIDENTAL,   AND  PUNITIVE   DAMAGES.
Notwithstanding  any other provision of this  Agreement,  neither party shall be
liable to the other party for any special, consequential, incidental or punitive
damages  that may arise out of this  Agreement  (including  but not  limited  to
damages for loss of sales, potential sales, profits or business),  regardless of
whether such other party has been informed of the possibility  that such damages
may occur.


<PAGE>


         22.      NOTICE.  Any notice  given in regard to this  Agreement  
shall be given in  writing  and shall be
delivered  personally,  or shall be sent by first class mail or registered  
certified  mail,  postage,  and charges
prepaid, to:

         if to Ostex:

                  Ostex International, Inc.
                  2203 Airport Way South

                  Suite 400
                  Seattle, Washington 98134

                  Attention:        Jeffrey J. Miller, Ph.D.,
                                    Senior Vice President, Corporate Development
                  Copy to:          Robert Glaser, President and COO

         if to Hologic:
                  Hologic, Inc.
                  590 Lincoln Street,
                  Waltham, MA 02154

                  Attention:        Joel Weinstein, Vice President - 
                                    Business Development
                  Copy to:          S. David Ellenbogen, Chairman and CEO

Any notice so given shall be  effective  upon the date of actual  receipt by the
addressee as evidenced by return receipt or other written  confirmation.  Either
party may by advance  notice  given  pursuant  to this  SECTION 21  designate  a
substitute address for receipt of future notices.

         23.  GOVERNING  LAW.  All  claims or  controversies  asserted  by Ostex
against  Hologic or Serex shall be construed and enforced in accordance with the
laws of the Commonwealth of Massachusetts. Any judicial action by Ostex relating
to the  relationship  between the parties  pursuant to this Agreement,  or goods
purchased or licensed  hereunder  (together with any  counterclaims  asserted by
Hologic or Serex),  shall be  brought  and tried in the State or Federal  Courts
located  in  Massachusetts.  All  claims or  controversies  asserted  by Hologic
against Ostex or WRF shall be construed and enforced in accordance with the laws
of the State of  Washington.  Any  judicial  action by Hologic  relating  to the
relationship between the parties pursuant to this Agreement,  or goods purchased
or licensed  hereunder  (together  with any  counterclaims  asserted by Ostex or
WRF),  shall be brought and tried in the State or Federal  Courts located in the
State  of  Washington.   Notwithstanding   the  foregoing,   interpretation  and
enforcement  of the  provisions of SECTION 18 shall be governed by and construed
in accordance with the Federal Arbitration Act.

         24. INTEGRATION.  It is the desire and intent of the parties to provide
certainty as to their future rights and undertakings herein. The parties in this
Agreement  have  incorporated  all   representations,   warranties,   covenants,
commitments and  understandings  on which they have relied in entering into this
Agreement,  and,  neither  party makes any covenant or other  commitment  to the
other concerning its future action. Accordingly,  this Agreement, in conjunction
with the  Co-Promotion  Agreement:-  (i)  constitutes  the entire  agreement and

<PAGE>

understanding  between the parties and there are no  promises,  representations,
conditions,  provisions or terms related  thereto other than those forth in this
Agreement  and  (ii)  supersedes  all  previous  undertakings,   agreements  and
representation between the parties, written or oral, with respect to the subject
matter hereof.  No modification  of, addition to, or waiver of any provisions of
this  Agreement  shall be binding upon either party hereto unless the same shall
be in writing duly executed by a duly authorized  representative of both parties
hereto.

         25.      MODIFICATION.  No  modification  to this Agreement  shall be 
 enforceable  unless made in writing
and signed by an authorized representative of each party.

         26. SEVERABILITY.  In the event that any provision of this Agreement is
determined to be invalid or unenforceable  for any reason,  such provision shall
be deemed  inoperative only to the extent that it violates or conflicts with law
or public policy and shall be deemed modified to the extent necessary to conform
thereto, and all other provisions hereof shall remain in full force and effect.

         27.  WAIVER.  No express or implied waiver by either party of any right
or remedy with  respect to a default by the other party under any  provision  of
this  Agreement  shall be deemed,  interpreted  or  construed as a waiver of any
right or remedy with  respect to any other  default  under the same or any other
provision hereof.

         28.      SUCCESSORS AND ASSIGNS.  This  Agreement  shall be binding 
     upon and shall inure to the benefit of the parties'  respective  successors
and assigns,  subject to the  restrictions on assignment set forth in SECTION 17
above.

         29.  NONCOMPETITION.  During the term of this Agreement,  Hologic shall
not enter into or maintain any marketing, licensing, or development agreement or
relationship  (whether  directly  or  by  reason  of  any  merger,  acquisition,
consolidation  or otherwise)  with any company (other than Serex) which competes
with Ostex to develop  biochemical  markers of bone resorption,  and Ostex shall
not enter into or maintain any marketing, licensing, or development agreement or
relationship  (whether  directly  or  by  reason  of  any  merger,  acquisition,
consolidation  or  otherwise)  with any company  which  competes with Hologic to
develop  devices to measure bone mass or other  structural  characteristics.  If
Hologic violates this provision, Ostex as its sole remedy for such violation may
at its  option  and upon 30 days  notice,  terminate  this  Agreement.  If Ostex
violates this  provision,  Hologic as its sole remedy for such  violation may at
its option and upon 30 days notice, terminate this Agreement.

         30. STANDSTILL  PROVISION.  During the term of this Agreement,  Hologic
shall  not make any offer  for,  and shall  not  actually  acquire  any legal or

<PAGE>

beneficial interest in the common stock or other securities of Ostex without the
prior written  consent of Ostex's  Board of Directors;  and Ostex shall not make
any offer for, and shall not actually  acquire any legal or beneficial  interest
in the common  stock or other  securities  of  Hologic  or Serex,  respectively,
without the prior written consent of Hologic's  Board of Directors.  The parties
each agree that any violation of this provision would cause  irreparable harm to
the other  party.  The parties each agree that the other party shall be entitled
to  all  equitable  remedies  available  to  it to  prevent  violation  of  this
provision,  as well as all other legal remedies, and if successful in any claim,
may recover from the violating  party all  reasonable  costs and attorneys  fees
expended by it in seeking such remedy.

         IN  WITNESS  WHEREOF,  the  parties  hereto  have  duly  executed  this
agreement the day and year last written below.

         DATED AND EFFECTIVE as of the date first written above.

                                           OSTEX INTERNATIONAL, INC.

                                           By       /S/ JEFFREY J. MILLER, PH.D.
                                                    Jeffrey J. Miller, Ph.D.,
                                                    Senior Vice President, 
                                                    Corporate Development

                                  HOLOGIC, INC.

                                           By       /S/ S. DAVID ELLENBOGEN

                                                    S. David Ellenbogen
                                                    Chairman and CEO


<PAGE>


                                  ATTACHMENT D

                               SEREX PATENT RIGHTS

  See Attached List as of 12/26/95 which represents Hologic's current knowledge
                          (to be updated and confirmed)


<PAGE>


                                     PATENTS

              (a list to be updated to the date of this Amendment)

1.    US Patent No. 5,451,504 (Serial No. 07/737,091).

      Method and Device for Detecting the Presence of an Analyte in a Sample

2.    US Serial No. 08/047,156

     An Integrated Packaging Holder Device for  Immunochromatographic  Assays in
Flow-Through or Dipstick Formats and foreign counterparts thereof and continuing
application US Serial No. 08/539,170 (continuation of 08/047,156)

3.    US Serial No. 08/196,092 and foreign Counterparts

4.    US Serial No. 08/493.420 and foreign counterparts

5.    US Serial No. 08/192,778


<PAGE>


                                 ATTACHMENT 3.4

                            Ostex Critical Reagent Specifications

                           OSTEX INTERNATIONAL, INC.

TITLE                   Lot No.         Doc No.         Rev.            Page
Ion Exchange 1H11                       2020            B               16 of 16
Purified
_______________________________________________________________________

7.0 Quality Control Testing

        7.1 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
_______________________________________________________________________
                Test            Acceptance               Pass/   Initials/
Parameter       Method          Criteria  Results         Fail    Date
_______________________________________________________________________
7.2  XXXXX      0004            XXXXX   _____           ____    ____
7.3  XXXXX      0006            XXXXX   _____           ____    ____
7.4  XXXXX      XXX             XXXXX   _____           ____    ____

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

XXX results


_________________________________________________________________________
Record reviewed by_________________________     ___________________
                    Quality Control             Date
Record reviewed by_________________________     ___________________
                                Quality Assurance               Date
Released _________________________________      Not Released _________
<PAGE>

<TABLE>
<CAPTION>

OSTEX INTERNATIONAL, INC.

TITLE                   Lot No.         Doc No.         Rev.            Page
NTx Concentrate                         2007            G               23 of 24
_______________________________________________________________________

                                                   -------ATTACHMENT 3-------
                                                            QC DATA SHEET
<S>             <C>     <C>             <C>            <C>       <C>             <C>

                Volume  NTx nromal      NTx Total       Protein  Protein         Specific Activity
                (ml)    BCE step 3.1    nanamol (ml)    step 8.3 Total mg        - (nmol/ml)/
                                        (ml)                     protein (mg/ml  mg/mlprotein
                                        nmol/ml BCE              Vol (ml))
                ____   ______          ________        _____     ________        __________

7.3.4 XXXX      Step 7.3.3
7.10 XXXX       Step 7.9
7.22 XXXX       Step 7.20
7.28 XXXX       Step 7.27

</TABLE>

Total Nanomole yield =  (total nmoles step 7.3.4)            x 100=___________%
                       -----------------------------
                         (total nmoles step 7.28)
QC materials used
Osteomark kit PN 9006 or 9006 LN _____, clibrator diluent PN 2022 LN____
PBS PN 2003 LN ___. Gold 300 pmol.ml NTx in PBS from PN 4010 LN 336C04

(A) Assay 1 dilution 1_______   (D) Assay 2, Dilution 1______________
(B) Assay 1 dilution 2_______   (E) Assay 2, Dilution 2______________
(C) Avg. of (A) and (B)_______  (F) Avg. of (D) and (E) ______________
(G) Percent difference of (C) and (F) ____ (if(C)is greater than 
 20%, repeat steps 8.1.3 to 8.1.5)
(H) Average (A),(B), (D) and (E)____ (Record (H) in the table above)
Note: Percent difference between x and y =100 (absolute 
value (x-y)/(average(x,y))

Number of aloquots:  _________
Volume of alquots:  __________
Total volume to inventory:________
Total nanomoles BCE to Inventory: _________





<PAGE>

                                 ATTACHMENT 6.2

                 MARKETING PLAN (TO BE APPENDED PER SECTION 6.2)


<PAGE>


                                ATTACHMENT 7.2.4

            Product Specifications - NTx Meter Strips and NTx Meters

                     See Attached - Subject to Modification


<PAGE>


            Product Specifications - NTx Meter Strips and NTx Meters

                   Hologic Point-of-Care Bone Resorption Test

                          DRAFT Specifications (Goals)

1.  The test is being designed so as to qualify for XXXXX.
2.  Specimens = XXXX.
3.  The method of XXXXXXXX must be simple, clean, nearly foolproof, and 
designed "to render the likelihood of erroneous results negligible." XXXXX
4.  There will be XXXXX.
5.  The target time to run the tests, from the beginning of application of the
specimen to the strips, is XXXXX.
6.  The XXXXX limits of the XXXXX.  The test should cover XXXXX.
7.  The  XXXXX limits of the XXXXX.  The test should cover XXXXX.
8. For both tests, XXXXX.
9.  XXXXX. There will be approximately the dame as those of comparable tests 
currently commercially available.
10.  Substances typically or occasionally found in XXX should not interfere 
with test performance.  Though the list remains to be specified, probable 
candidates for inclusion are: XXXXX.

TEST FORMAT

11.  Initiation of any timing should be simple. (E.G.,XXXXX).
12.  Once the (timed) test begins, and until it concludes, XXXX should be 
required.

CONTROLS

13.  XXXXX will be supplied to users, with appropriate instructions for use.  
The goal is to have XXXX, and controls XXXX which are to be run as infrequently
 as possible, while providing acceptable levels of control.

METER FUNCTION

14.  The meter will detect XXXX from each strip, and then using XXXX will 
calculate concentrations and the XXXX.
15.  The result reported by the meter will be the XXXXX.
16.  XXXXX.
17.  The meter will XXXXX as required.   XXXXXX.

ERROR CONDITIONS

18.  XXXXX.
19.  If the meter detects a XXXX, no test result will be reported, and the 
meter will indicate XXXX.
20.  Application of an XXXXXXX will detedted by the meter, and no test result 
will be reported.

METER MAINTENANCE

21.  The XXXX of the meter will be cleanable using XXXX.
22.  If a meter malfunctions, it will be returned to the manufacturer for 
repair, and a replacement meter will be given to the user.

METER POWER, RELIABILITY

23.  The meter will be powered by XXXX. Target XXXX lifetime is XXXXX.
24.  Meter XXXXXXXXXXXXX in production.

STABILITY

25.  Target strip stability at launch XXXX.

METER REGULATORY REQUIREMENTS

26.  The meter will be manufactured according to XXXXX.
27.  The meter will have the XXXX.
28.  The meter will meet XXXX limits XXXX and XXXX limits XXXXX.


<PAGE>


                                ATTACHMENT 13.1.2

            OSTEX PATENT RIGHTS AND KNOW-HOW - EXCEPTIONS TO WARRANTY

Pursuant to paragraph  14.1,  the WRF and Ostex on June 12, 1996,  filed a civil
action for patent  infringement  against  Osteometer  Biotech A/S and Diagnostic
Systems Laboratories, Inc. in the U.S. District Court of the Western District of
Washington at Seattle (Civil Action No.  C96-0910WD).  The patent in suit,  U.S.
Patent  No.  5,455,179,  claims a method  of  monitoring  degradation  of type I
collagen   using  an  antibody  that  binds  to   carboxy-terminal   telopeptide
metabolites of type I collagen in urine and other body fluids.  Plaintiffs claim
that the CrossLaps  ELISA Kit  manufactured  and  distributed  by the defendants
infringes the `179 patent.  Defendants have  counterclaimed that the `179 patent
is  invalid,  not  infringed,  and  unenforceable.  Osteometer  has also  denied
jurisdiction. The case is set for trial commencing 12/2/97.

     Ostex  is  also  defending  two  of  its  European  patents  in  opposition
proceedings in the European Patent Office.  European Patent No. 394,296 has been
opposed by Osteometer Biotech A/S,  F.Hoffman-LaRoche  AG, and Metra Biosystems,
Inc.  European  Patent No.  502,928 has been opposed by Osteometer  Biotech A/S,
Metra Biosystems, Inc., and Boehringer Mannheim GMBH.


<PAGE>



                                 ATTACHMENT 16.5

                            HOLOGIC TRADEMARK FILINGS

MARK            REGISTRATION NO.       ISSUE DATE              NOTES
----            ----------------       ----------              -----
ACCLAIM         1,70,513               4/23/96           X-Ray Technology, Inc.
CER             1,751,849              2/9/93                     _
HOLOGIC         1,652,292              7/30/91                    _
XXXXXXX         XXXXXXXXXXXX           XXXXX                  XXXXXXXXX.
XXXXXXX         XXXXXXXXXXXX           XXXXX                  XXXXXXXXX
QDR             1,510,840              11/1/88     Assigned to X-Ray Technology,
                                                                        

QDR-1000        1,506,996              10/4/88     Assigned to X-Ray Technology,
                                                                  Inc. 11/4/91
SAHARA          2,008,809              10/15/96                    _
XXXXXXX         XXXXXXXXXXX            XXXXXX                 XXXXXXXXXX
UBA             1,529,557              3/14/89                     _

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX