<PAGE>
 
                                                                   Exhibit 10.15


                         TRANSITION SERVICES AGREEMENT


                                by and between

HOECHEST AG
(hereinafter referred to as "Hoechst")


and


The Companies listed in Annex A)
(hereinafter referred to as the "Service Entities")

- on the one side -

and

DIAGNOSTICS HOLDING, INC.
(hereafter referred to as "Dade")

and

The Companies listed in Annex B)
(hereinafter referred to as the "Acquired Entities")

- on the other side)


dated as of September 30, 1997

                                      -1-
<PAGE>
 
                                    CONTENTS
<TABLE>
<CAPTION>

<S>                                                                     <C>
Directory of Annexes                                                      2

Preamble                                                                  3

Article 1 - Service Provided                                              3

Article 2 - Remuneration for Services                                     3

Article 3 - Invoicing and Payment                                         9

Article 4 - Liability                                                    10

Article 5 - Excusable Delay                                              12

Article 6 - Term and Termination                                         13

Article 7 - Confidentiality                                              15

Article 8 - Arbitration                                                  16

Article 9 - Miscellaneous                                                18
 
</TABLE>
DIRECTORY OF ANNEXES

Annex 1.1 -    Services

Annex 1 4 -    Service Coordinators

                                      -2-
<PAGE>
 
Preamble

A.   Hoechst and Dade have entered into an Agreement and Plan of Combination
     dated as of June 24, 1997 (the "Combination Agreement"). Under the
     Combination Agreement Hoechst and Dade have agreed to combine all of Dade's
     business and Hoechst's human in vitro diagnostic business (the "Business").
     (Capitalized terms not otherwise defined in this Agreement shall have the
     meanings ascribed to them in the Combination Agreement); and

B.   As set forth in Section 2.1(g) of the Combination Agreement, Hoechst and
     Dade agreed that Dade and the Acquired Entities shall enter into one or
     more transition services agreements relating to certain transitional
     administrative and support services for the Business for a certain period
     after the completion of the transactions contemplated by the Combination
     Agreement in accordance with the terms of this Agreement;

NOW, THEREFORE, subject to the terms, conditions, covenants and provisions of
this Agreement, Hoechst and Dade mutually covenant and agree as follows:

                                   Article 1
                               Services Provided
                                        
1.1  Upon the terms and subject to the conditions set forth in this Agreement,
     Hoechst and the Service Entities will provide to the Acquired Entities for
     the Business each of those administrative and support services listed
     individually or included within a category of service listed in Annex 1.1,
     which is attached to and made part of this Agreement, in the countries set
     forth in that Annex (hereinafter referred to individually as a
     "Transitional Service", and collectively as the "Transitional Services"),
     during the period until December 31, 1999 unless terminated prior thereto
     (hereinafter referred to as the "Time Periods" for all of the Transitional
     Services, and the "Time Period" for each Transitional Service). The
     Acquired Entities shall purchase and off-take the Transitional Services
     during the term of each of such service in amounts of not less than fifty
     (50%) of the quantities as of the date hereof, provided that the Acquired
     Entities shall continue to lease all space leased as of the date hereof.

1.2  The parties have attempted to list on Annex 1.1 (i) each service rendered
     by Hoechst or a Hoechst Entity in 1996 and 1997 to the Business (except for
     services to be provided by InfraServ GmbH & Co. Marburg KG and HiServ GmbH)
     and (ii) which Hoechst and the Service Entities should provide for an
     interim period in order to enable the Acquired Entities to operate
     consistent with past practice on a stand-alone basis (collectively the
     "Required Services") but acknowledge that Annex 1.1 may be incomplete.
     Thus, if a service desired by Dade or an Acquired Entity is not listed in
     Annex 1.1 but is a Required Service, such Required Service
                                      -3-
<PAGE>
 
     shall be added to Annex 1.1, upon the terms and conditions of this
     Agreement. Such Required Service shall be deemed to be a Transitional
     Service for the purpose of this Agreement.

1.3  ln providing the Transitional Services, Hoechst and the Service Entities
     may employ the services of third parties (the "Outside Service Providers")
     to the extent such Outside Service Providers are either routinely utilized
     to provide similar services to Hoechst enterprises or are reasonably
     necessary for the efficient performance of any Transitional Service or such
     Outside Service Provider is, in Hoechst's reasonable determination,
     otherwise qualified to render such Transitional Service at quality
     standards not lower than in 1996; provided that Hoechst and the Service
     Entities shall not employ for the purpose of this Article 1.3 any Outside
     Service Provider which is a competitor of Dade or any of the Acquired
     Entities. Whether or not an Outside Service Provider is employed, Hoechst
     and the Service Entities shall be responsible for the delivery of the
     Transitional Services in compliance with the terms of this Agreement.

1.4  Hoechst and Dade shall each nominate a representative to act as the primary
     contact person for the supervision of the implementation of this Agreement
     (collectively, the "Primary Coordinators") The initial Primary
     Coordinators shall be John Doherty for Dade and Derek Gribbin for Hoechst.
     The initial coordinators for specific Transitional Services in each country
     shall be the individuals named in the description of such Transitional
     Service in Annex 1.4 (the "Service Coordinators") with the name, address
     and phone number of each such Service Coordinator set forth on Annex 1.4.
     Hoechst and Dade shall advise each other in writing of any change in the
     Primary Coordinators and any Service Coordinator. Hoechst and Dade agree
     that a copy of all communications relating to the provision of the
     Transitional Services shall be directed to the Primary Coordinators.

1.5  Hoechst and each of the Service Entities represent and warrant to Dade that
     they have, and covenant with Dade that they shall maintain or have
     available through Outside Service Providers all necessary assets and
     personnel in order to fulfill their obligations hereunder.

1.6  To the extent reasonably required for the personnel to perform the
     Transitional Services, each of the parties shall provide personnel
     designated by the other with access to its equipment, office space, plants,
     telecommunications and computer equipment and systems, and any other areas
     and equipment, provided that such access does not include the use thereof
     in the provision of any Transitional Service and does not unreasonably
     interfere with such other party's conduct of its business. Any confidential
     information received by either party due to such access shall be subject to
     the provisions of Article 8 below.

                                      -4-
<PAGE>
 
1.7  Hoechst hereby represents and warrants to Dade that the amount of
     consideration paid or to be paid by the Acquired Entities for each
     Transitional Service is not greater than the actual average purchase price
     per unit paid for such Transitional Service by the Business during the 1996
     calendar year, subject to an increase of Service Costs as agreed in Article
     2.2 below (the "1996 Historical Prices").

1.8  Hoechst shall ensure that the Acquired Entities shall be neither assessed
     nor liable to pay any (i) termination or similar fee, expense or other
     liability of any kind whatsoever relating to, arising from or in connection
     with any reduction in the level of use, or deletion, of any Transitional
     Service by an Acquired Entity, or (ii) fee, expense or other liability of
     any kind whatsoever relating to, arising from or in connection with any
     remnant, residual or other similar costs relating to any Transitional
     Service. Nothing in this Article 1.8 shall give Dade or the Acquired
     Entities the right to assert that the 1996 Historical Prices should be
     lower because they include a component which could be regarded as a fee
     described above.

1.9  Hoechst promptly shall pay and shall indemnify and hold harmless the
     Acquired Entities from any damage (except loss of profit) from or in
     connection with any breach by Hoechst of any of the covenants,
     representations or warranties in Sections 1.5, 1.7 and 1.8 of this
     Agreement. All payments by Hoechst hereunder due to the Acquired Entity
     concerned shall be made in the relevant local currency.

1.10 In the event of any of Dade and the Acquired Entities makes a good faith
     argument that Hoechst is in breach of the representations and warranties
     set forth in Articles 1.7 and 1.8 above, and Hoechst disagrees, Hoechst and
     Dade shall make every reasonable effort to amicably resolve such difference
     (which reasonable effort shall include a reasonable disclosure of documents
     by Hoechst to Dade to permit verification of the actual 1996 prices). In
     the event Hoechst and Dade cannot resolve any difference connected
     therewith, Hoechst shall cause a qualified independent auditor subject to
     Dade's approval, which will not be unreasonably withheld, promptly to
     certify that no breach of Articles 1.7 and 1.8 has occurred. Such auditor's
     certification shall set forth in reasonable detail the rationale for the
     auditor's opinion. The costs for such audit shall be borne by the parties
     in accordance with Section 91 et seq. Civil Procedure Act (ZPO).

1.11 The Acquired Entity shall have no obligation to continue to use any of the
     Transitional Services and may delete any Transitional Service that Hoechst
     is providing to the Acquired Entities by giving Hoechst written notice of
     its desire to delete any or all Transitional Services. For this purpose a
     written termination notice having effect three (3) months to the end of a
     month must be provided by Dade for the deletion of a Transitional Service,
     provided that each Acquired Entity shall in good faith attempt to give an
     earlier notice to the Service Entity so that as much notice is given as
     possible.

                                      -5-
<PAGE>
 
1.12 Hoechst shall use best efforts (utilizing all commercially feasible means
     including after consultation with Dade at Hoechst's free discretion the use
     of Outside Service Providers) to provide at the Acquired Entities' cost
     (unless such service was provided historically in which case Article 2
     shall apply), on or prior to December 31, 1997, as part of the service set
     forth in Annex 1.1 as "Accounting-Finance," each and every financial
     reporting service set forth in Annex 1.1, (a) (the "Financial Reporting
     Services"). In addition, as part of the foregoing and also at the Acquired
     Entities' cost, Hoechst shall employ its best efforts to implement the
     steps as set forth in Annex 1.12(b). The costs to be borne by the Acquired
     Entities hereunder shall be based upon the incremental cost of providing
     the Financial Reporting Services above and beyond those provided on a
     historical basis. Prior to incurring such incremental cost in connection
     with providing such Financial Reporting Services Hoechst shall consult with
     Dade. For the avoidance of doubt: Article 1.7 does not apply to the
     Financial Reporting Services other than those services provided
     historically.

                                   Article 2
                           Remuneration for Services
                                        
2.1  The remuneration for the services delivered hereunder shall be as set forth
     in Annex 1.1 (the "Base Price"). V.A.T. or similar taxes are to be paid
     separately by the Acquired Entities.

2.2  Upon written request of either (i) Hoechst or the Service Entity concerned
     or (ii) Dade or the Acquired Entity concerned, as the case may be, the Base
     Price shall be adjusted for any change of Service Costs, as defined
     hereinafter. For purposes of this Agreement, "Service Costs" shall mean all
     (i) out-of-pocket expenses (including reasonable fees of Outside Service
     Providers and fifty percent (50%) of insurance fees to protect Hoechst and
     the Service Entities against liability hereunder (cf. Article 4), provided,
     that in no event shall Dade and the Acquired Entities be liable for any
     insurance fees hereunder in excess of DM 50,000 in the aggregate) paid to
     third parties by Hoechst or the relevant Service Entity in order to provide
     the Transitional Services, including actual expenses paid by Hoechst or the
     relevant Service Entity in order to comply with legal regulations
     applicable to the provision of Transitional Services which become effective
     after 1996, and (ii), costs relating to higher depreciation as a result of
     investments made by Hoechst or the relevant Service Entity in order to
     comply with legal regulations applicable to the provision of Transitional
     Services which became effective after 1996.

2.3  A change in the Base Price of a service which results from a Price
     Adjustment Event shall become effective for such service immediately
     following the occurrence of a Price Adjustment Event, provided that any
     change shall be deemed effective only if not disputed by any party
     concerned following the receipt of a written notice from the party
     requesting a price adjustment, which notice shall contain a reasonable
     explanation for the change of the Base Price in

                                      -6-
<PAGE>
 
     accordance with Article 2.2 above. A decrease in the Base Price resulting
     from a Price Adjustment Event, however, shall have retroactive effect to
     such date on which Hoechst or the Hoechst Entity concerned knows or should
     have known of such change. On an annual basis, a responsible financial
     officer of the relevant Service Entity in their capacity as such without
     personal liability and, if requested by Dade, an independent auditing firm
     reasonably acceptable to Dade, shall certify that any changes in the Base
     Price in the preceding year were correct and in accordance with the terms
     of this Agreement. Unless the changes of the Base Price were incorrect, all
     costs connected with the employment of the independent auditors shall be
     borne by Dade.

2.4  In the event any party disputes the delivered evidence of any changes in
     Service Costs, information about such costs shall be disclosed to all
     parties concerned and Hoechst and Dade shall make on behalf of all parties
     concerned every reasonable effort to amicably determine the substantiated
     cost changes. If Hoechst and Dade cannot agree on an adjustment of the Base
     Price, then any adjustment of the Base Price shall be determined by an
     internationally recognized firm of auditors to be appointed by mutual
     agreement of Hoechst and Dade or, failing such agreement, upon request of
     either party by Deloitte & Touche after hearing both parties. Confidential
     information received by such firm of auditors shall, upon request of
     Hoechst or the Service Entity concerned, not be disclosed to Dade or the
     Acquired Entity concerned. Any changes agreed to or determined by the
     auditors shall be given retroactive effect.

     The firm of auditors shall act as appraiser (known as Schiedsgutachter) in
     the meaning of Sections 315 et seq. Civil Code (BGB) and not as arbitrator
     (known as Schiedsrichter), and its determination shall be final and binding
     on the parties.

     The costs of the appraisal proceeding, including the cost of the respective
     attorneys, witnesses and experts in connection with such arbitration shall
     be borne by the parties in accordance with Sections 91 et seq. German Civil
     Procedure Act (ZPO) as directed in the auditor's appraisal.

                                   Article 3
                             Invoicing and Payment
                                        
3.l  Transitional Services shall be invoiced to the Acquired Entities by Hoechst
     or the relevant Service Entities in the month following the month in which
     the Transitional Services were rendered. Payment of invoices shall be made
     in the currency of the jurisdiction in which the Transitional Service which
     is the subject of the Invoice is received. Each invoice shall include a
     summary list of the previously agreed upon Transitional Services for which
     there are fixed fees, together with documentation supporting each of the
     invoiced amounts that are not covered by the fixed fee agreements. The
     total of this list and supporting detail

                                      -7-
<PAGE>
 
     will equal the invoice total, and will be provided under separate cover
     apart from the Invoice.

3.2  Provided that the invoice is received at least ten (10) days prior to the
     due date, Invoices become due for payment on the 25th day after the end of
     the invoiced period. Payments by the Acquired Entities shall be effected
     free of charge to a bank account designated by Hoechst or the Service
     Entities. Delayed payments shall bear interest at 10 percentage points p.a.

                                   Article 4
                                   Liability
                                        
4.l  Hoechst and the Service Entities shall perform the Transitional Services
     hereunder exercising the greater of (i) the same degree of care they
     usually apply in their own matters, (ii) the same degree of care applied by
     a prudent business person or (iii) the same degree of care they exercised
     historically in performing the same or similar services for the Business
     during the 1996 calendar year, provided, however, that Hoechst and the
     Service Entities, as the case may be, may be held contractually or legally
     liable only for claims with regard to the fulfillment of this Agreement

     (a)  if the relevant management (Vorstand; Geschaftsfuhrung) has
          negligently or willfully violated the obligation of due care as stated
          above, or

     (b)  if a person, including employees of Hoechst or a Service Entity
          performing contractual tasks hereunder (Erfullungsgehilfe) other than
          the management of such company, has grossly negligently or willfully
          caused a damage to an Acquired Entity.

     Notwithstanding anything to the contrary contained herein, in the event
     Hoechst or a Service Entity commits an error with respect to, or
     incorrectly performs or fails to perform, any service, Hoechst or the
     Service Entity, at the Acquired Entity's request, shall use reasonable best
     efforts to promptly correct such error, or to reperform or perform such
     service.

4.2  To the extent that Hoechst or a Service Entity, as the case may be, is
     responsible for damages as set forth in Article 4.1 lit. (a) and lit. (b)
     above, Hoechst or the responsible Service Entity shall fully indemnify and
     hold harmless the Acquired Entity concerned against any damages (excluding
     damages for loss of profit). Unless such damages were caused by willful
     misconduct of Hoechst or the Service Entities, Hoechst's or the Service
     Entities', as the case may be, indemnification obligation hereunder shall
     only apply to the extent that in each incident (or series of related
     incidents) such damages exceed DM 25,000 (in words: Deutsche Mark twenty
     five thousand).

                                      -8-
<PAGE>
 
     The liability limitations referred to in this Article 4.2 shall not apply
     in cases of willful misconduct.

4.3  To the extent that the parties submit to each other information or give
     advice without remuneration outside of their duties under this Agreement,
     neither party shall assume any liability for the correctness of such
     information or advice.

4.4  Subject to the terms and conditions stated hereinafter Hoechst guarantees
     that each of the Service Entities will

     (a)  always have sufficient capital to make the expenditures necessary to
          maintain the quantity and the quality of the Transitional Services
          which the Service Entities are obligated to provide under this
          Agreement; and

     (b)  make all payments due to the Acquired Entities under this Agreement,
          including payments due to breach of contract

     (hereinafter the "Performance Guarantee").

     Any Service Entity can call Hoechst liable under the Performance Guarantee,
     if (i) the relevant Service Entity has been liquidated and the delivery of
     the services under this Agreement will not be continued by a successor, or
     (ii) if the relevant Service Entity's assets become subject of a bankruptcy
     procedure and the trustee in bankruptcy or an successor is not prepared to
     fully continue to provide the services under the terms of this Agreement,
     or (iii) the enforcement of a final arbitration award against the relevant
     Service Entity in favor of the Acquired Entity on the basis of this
     Agreement is fruitless. Hoechst hereby agrees to join and be bound by any
     arbitration proceeding brought by the Acquired Entity against any Service
     Entity relating to this Agreement and to resolve, to the extent possible,
     any dispute with respect to Hoechst's liability under the Performance
     Guarantee in such proceeding.

     Upon request by any Acquired Entity and with a view to prevent or limit any
     material non-performance or mal-performance of any Service Entity under
     this Agreement, Hoechst shall cause (if legally possible, otherwise Hoechst
     shall use its best efforts to cause) the Service Entity concerned to fully
     comply with the terms of this Agreement (unless the Service Entity
     concerned is excused from so complying under the terms of this Agreement).
     Such request of any Acquired Entity shall be set forth in a written notice
     stating in reasonable detail why and that the Service Entity concerned does
     not comply or may be reasonably expected not to comply in a material way
     with the terms of this Agreement.

                                      -9-
<PAGE>
 
                                   Article 5
                                Excusable Delay

5.1  Except as otherwise expressly provided in this Agreement, neither party
     hereto shall be liable for a failure to perform hereunder for reasons of
     force majeure, including acts of God, acts of a public enemy, acts of the
     governments of any state or political subdivision or any department or
     regulatory agency thereof or entity created thereby, quotas, embargoes,
     acts of any person engaged in subversive activity or sabotage, fires,
     floods, explosions, or other catastrophes, epidemics, or quarantine
     restrictions, strikes or other labor stoppages, slowdowns or disputes, or
     any other cause beyond the control of the parties ("Reasons of Force
     Majoure").  Each party shall use its best efforts to cure any such cause
     preventing its performance and to resume performance.

5.2  In the event Hoechst or a Hoechst Entity reasonably believes that delivery
     of Transitional Services may be delayed, impaired or prevented by Reasons
     of Force Majeure, it shall (a) immediately notify the Acquired Entity
     concerned of the possibility of such cause, (b) immediately notify the
     Acquired Entity of such actual cause, and (c) use its best efforts to keep
     this Agreement operative.

5.3  In the event an Acquired Entity reasonably believes that receiving of
     Transitional Services may be delayed due to a Reason of Force Majeure, such
     Acquired Entity shall (a) immediately notify the Hoechst Entity concerned
     of the possibility of such cause, (b) immediately notify the Hoechst Entity
     of such actual cause, and (c) use its best efforts to keep this Agreement
     operative.

5.4  If and to the extent any Acquired Entity shall be unable to off-take a
     Transitional Service as a result of a Reason of Force Majoure, such
     Acquired Entity shall pay any actual damage incurred by Hoechst or the
     Service Entity thereof, provided that Hoechst or the Service Entity
     concerned shall use its best efforts to mitigate any such damage.

                                   Article 6
                             Term and Termination

6.1  This Agreement shall become effective on the Closing Date and shall remain
     in force until the expiration of the longest Time Period unless all of the
     Transitional Services are deleted by the parties in accordance with Article
     6.2 below.  This Agreement shall in any event terminate on December 31,
     1999.

6.2  If either party (hereafter called the "Defaulting Party") shall fail to
     perform or default in the performance of any of its obligations under this
     Agreement, the other party receiving or rendering Transitional Services
     hereunder (hereinafter called the "Non-Defaulting Party") may give written
     notice to the Defaulting Party specifying the nature of such failure or
     default and stating that the Non-

                                      -10-
<PAGE>
 
     Defaulting Party intends to terminate this Agreement if such failure or
     default is not cured within fifteen (15) days of such written notice. If
     any failure or default so specified is not cured within such fifteen (15)
     day period, the Non-Defaulting Party may elect to immediately terminate
     this Agreement; provided, however, that if the failure or default relates
     to a dispute made in good faith by the Defaulting Party, the Non-Defaulting
     Party may not terminate this Agreement pending the resolution of such
     dispute. Such termination shall be effective upon giving a written notice
     of termination from the Non-Defaulting Party to the Defaulting Party and
     shall be without prejudice to any other remedy which may be available to
     the Non-Defaulting Party against the Defaulting Party. Furthermore, the 
     Non-Defaulting Party shall be entitled to immediately terminate either this
     Agreement or any of the Transitional Services provided hereunder if the
     Defaulting Party is not able to cure within thirty (30) days a Reason of
     Force Majeure as set forth in Article 5 hereunder.

6.3  Dade specifically agrees and acknowledges that all obligations of Hoechst
     and the Service Entities to provide each Transitional Service shall
     immediately cease upon the expiration of the Time Period for such
     Transitional Service, and Hoechst's obligations to provide all of the
     Transitional Services shall immediately cease upon the termination of this
     Agreement.

6.4  Without prejudice to the survival of the other agreements of the parties,
     the following obligations shall survive the termillatioll of this
     Agreement: (i) for the period set forth therein, the obligations of each
     party under Articles 4 (Liability), 7 (Confidentiality) (ii) Hoechst's or
     the Service Entities' right to receive the compensation for the
     Transitional Services provided prior to the effective date of termination.

6.5  Within ten (10) days of the earlier of (i) notice by Dade to Hoechst of
     termination of any of the Transitional Services set forth in Annex 1.1, or
     (ii) Dade's earlier request at any time more than sixty (60) days after the
     15 date of this Agreement, Hoechst and the Service Entities shall, at
     Hoechst's sole expense transfer and deliver to Dade all master and
     transaction files necessary and desirable, in Dade's sole discretion, for
     Dade's conversion to new data processing systems.  Such files shall be
     delivered in the form they exist in Hoechst's or the Service Entities' data
     processing systems.

                                   Article 7
                                Confidentiality
                                        
7.1  Each party shall regard as confidential and proprietary all of the
     information communicated to it by the other party from and after the date
     hereof in connection with this Agreement (including but not limited to the
     Specifications and any and all documents or other information relating
     thereto, whether or not marked "confidential") (which information shall,
     subject to the exception set forth in 

                                      -11-
<PAGE>
 
     Article 8.4 hereof, at all times remain the property of the disclosing
     party), referred to herein as "Confidential Information". Confidential
     Information includes such information disclosed by a party orally or
     visually, directly or indirectly. Confidential Information of a party is
     also deemed to include identification of problems to be solved, areas for
     process, product and equipment improvements, and Confidential Information
     of third parties, which are observed, identified or disclosed under or as a
     result of this Agreement.

7.2  During the term of this Agreement and for a period of ten (10) years
     following termination, neither party shall, without the other's prior
     written consent, at any time (a) use such Confidential Information for any
     purpose other than in connection with the performance of its obligations
     under this Agreement, or (b) disclose any portion of such Confidential
     Information to third parties. Each party shall promptly at the termination
     of this Agreement return to the disclosing party all such Confidential
     Information which is in written or tangible form (including all copies,
     summaries and notes of the contents thereof), but its counsel may retain a
     single copy thereof for record purposes.

7.3  Each party shall disseminate Confidential Information of the other party to
     its employees, agents and subcontractors only on a need-to-know" basis, and
     shall use the same degree of care in protecting such Confidential
     Information of the other party as it does for its own information of like
     kind. Each party shall cause each of its employees, agents and
     subcontractors who has access to such Confidential Information to comply
     with the terms and provisions of this Article 7 in the same manner as it is
     bound hereby, with it remaining responsible for the actions and disclosures
     of any such employees, agents and subcontractors.

7.4  Notwithstanding the foregoing, a party's obligations pursuant to the above
     paragraph shall not apply to (i) information that, at the time of
     disclosure, is, or after disclosure becomes part of, the public domain
     other than as a consequence of a breach of this Agreement, (ii) information
     that was known or otherwise available to the receiving party prior to the
     disclosure by the disclosing party, (iii) information disclosed by a third
     party to the receiving party after the disclosure by the disclosing party,
     if such third party's disclosure does not violate any obligation of the
     third party to the disclosing party, (iv) information that is independently
     developed by the receiving party, or (v) which is required to be disclosed
     by law or governmental order.

7.5  With respect to any confidential information. each party agrees that upon
     the discovery of any inadvertent disclosure or unauthorized use of said
     information, or upon obtaining notice of such a disclosure or use from the
     other party, it shall take all necessary actions to prevent any further
     inadvertent disclosure or unauthorized use, and such other party shall be
     entitled to pursue any other remedy which may be available to it.

                                     -12-
<PAGE>
 
                                   Article 8
                                  Arbitration

8.1  In the event of any dispute or disagreement between the parties as to the
     interpretation of any provision of this Agreement (or the performance of
     any obligations hereunder), except pursuant to Article 2.4, the matter,
     upon written request of either party, shall be referred to representatives
     of the parties for decision, each party being represented by one senior
     officer who has no direct operational responsibility for the matters
     contemplated by this Agreement and who is authorized to settle the dispute
     without further consultation with any other officer (the
     "Representatives"). The Representatives shall promptly meet in a good faith
     effort to resolve the dispute. If the Representatives do not agree upon a
     decision within thirty (30) days after reference of the matter to them,
     each of the parties shall be free to exercise the remedies available to it
     under Article 8.2.

8.2  Except as provided in Article 2.4, any controversy, dispute or claim
     arising out of or relating in any way to this Agreement or the other
     agreements contemplated hereby that cannot be resolved by negotiation shall
     be settled exclusively by arbitration in Frankfurt am Main, Germany. The
     arbitration shall be conducted in the English language. Such arbitration
     shall be administered by the German Institution for Arbitration (the
     "Arbitral Body") in accordance with the then prevailing Arbitration Rules
     of the German Institution for Arbitration e.V. (DIS) (except as otherwise
     provided herein), by three independent and impartial arbitrators, one of
     whom shall be appointed by Hoechst and one of whom shall be appointed by
     Dade. The fees and expenses of the Arbitral Body and the arbitrators shall
     be shared equally by the parties and advanced by them from time to time as
     required; provided that at the conclusion of the arbitration, the
     arbitrators shall award costs and expenses (including the costs of the
     arbitration previously advanced and the reasonable fees and expenses of
     attorneys, accountants and other experts) and interest (at the rate of
     eight per cent (8%) per annum) in accordance with Article 8.3 below. No
     pre-arbitration discovery shall be permitted, except that the arbitrators
     shall have the power in their sole discretion, on application by either
     party, to order pre-arbitration examination of the witnesses and documents
     that the other party intends to introduce in its case-in-chief at the
     arbitration hearing. The arbitrators shall render their award within ninety
     (90) days of the conclusion of the arbitration hearing. The arbitrators
     shall not be empowered to award either party any punitive damages in
     connection with any dispute between them arising out of or relating in any
     way to this Agreement or the transactions arising hereunder, and each party
     hereby irrevocably waives any right to recover such damages.
     Notwithstanding anything to the contrary provided in this Article 8 and
     without prejudice to the above procedures, either party may apply to any
     court of competent jurisdiction for temporary injunctive or other
     provisional judicial relief if such action is necessary to avoid
     irreparable damage or to preserve the status quo until such time as the
     arbitration panel is convened and available to hear such party's request
     for temporary relief. The

                                      -13-
<PAGE>
 
     award rendered by the arbitrators shall be final and not subject to
     judicial review and judgment thereon may be entered in any court of
     competent jurisdiction.

8.3  The costs of the arbitration, including the cost of the respective
     attorneys, witnesses and experts in connection with such arbitration shall
     be borne by the parties in accordance with Sections 91 et seq. German Civil
     Procedure Act (ZPO) as directed by the arbitrators.

                                   Article 9
                                 Miscellaneous
                                        
9.1  This Agreement shall replace all existing agreements, understandings or
     other arrangements between the Acquired Entities on the one side and
     Hoechst and the Service Entities on the other side relating to the subject
     matter of this Agreement, but it shall not affect any existing agreements
     with third parties. In addition, any agreements by and among the Acquired
     Entities are neither affected hereby.

9.2  All notices, reports, and consents required or permitted to be given under
     this Agreement shall be in writing and deemed given when hand delivered or
     delivered by documented overnight delivery service, or sent by telecopy,
     telefax, or other electronic transmission service, provided a confirmation
     copy is also sent no later than the next business day by first class mail,
     return receipt requested, to the party to whom the same is directed at its
     address whereby Hoechst shall receive a copy of all notices to the Service
     Entities to the address as set forth below and Dade shall receive a copy of
     all notices to the Acquired Entities to the address as also set forth
     below, or with respect to both, to such other address as such party shall
     designate by notice under this Article 9.2:

     Notices to Hoechst:
     -------------------

         Hoechst Aktiengesellschaft
         Bruningstrasse 50
         65926 Frankfurt a. M.
         GERMANY
         Attention:  Contract Controlling
         Facsimile No.: (+49-69) 305-16 404

                                     -14-
<PAGE>
 
     Notices to Dade:
     ----------------

         Dade International Inc.
         1717 Deerfield Road
         P.O. Box 778
         Deerfield, Illinois 60015
         U.S.A.
         Attention: General Counsel
         Facsimile No.: (+1-847) 267-5376

     with a copy (which shall not constitute notice hereunder) to:
     -------------------------------------------------------------

         Bain Capital, Inc.
         Two Copley Place
         Boston, Massachusetts 02116
         U.S.A.
         Attention: Steven G. Pagliuca
                    John Connaughton
         Facsimile No.: (++1-617) 572-3274

     and:
     --- 

         Kirkland & Ellis
         199 Bishopsgate
         London EC2M 3TY
         ENGLAND
         Attention: Karl S. Okamoto
                    David Patrick Eich
         Facsimile No.: (+44-171) 814-6623

9.3  This Agreement may not be assigned by either party without the consent of
     the other and any assignment without such consent shall be void, provided
     that

     (a)  the Service Entities may assign this Agreement (including their
          obligations hereunder) to (i) any of their subsidiaries, affiliates or
          by means of their merger with or into any other company whether or not
          they will be the surviving company or (ii) any entity with which they
          establish a joint venture or similar business relationship; and

     (b)  the Acquired Entities may assign this Agreement under the same
          circumstances as Hoechst or the Service Entities (cf. lit. (a) above),
          provided that any such assignment does not materially alter the scope
          or the nature of the Transition Services. It is understood that the
          Acquired Entities are entitled to pass through to third parties which
          assume or operate assets of the Acquired Entities the right to receive
          Transitional

                                     -15-
<PAGE>
 
          Services. Furthermore, the Acquired Entities may assign their rights
          pursuant to this Agreement (including their rights to indemnification)
          to any of their or their affiliates' lenders as collateral security.

9.4  The construction, performance, and completion of this Agreement shall be
     governed by the substantive law (and not the law of conflicts) of Germany.
     Place of venue shall be Frankfurt a.M.

9.5  Whenever possible, each provision of this Agreement shall be interpreted in
     such a manner as to be effective and valid under applicable law. The
     determination by any court of competent jurisdiction that one or more of
     the sections or provisions of this Agreement are unenforceable shall not
     invalidate this Agreement, and the decision of such court shall be given
     effect so as to (i) limit, to the extent possible, the sections or
     provisions of this Agreement which are deemed unenforceable and (ii)
     replace any such sections or provisions with a section or provision which
     accomplishes, to the extent possible, the original business purpose of such
     provision in an enforceable manner. To the extent such determination has a
     material impact upon the economic expectations of the parties hereto, the
     parties agree to make appropriate modifications to this Agreement to take
     such impact into account.

9.6  Except as required by law or compelled by legal process, neither party
     shall, without the prior written consent of the other, disclose any of the
     material terms or conditions contained herein.

9.7  Any amendment of or supplement to this Agreement, including this provision
     and the Annexes, must be in writing to be valid and must be at least signed
     by Hoechst and Dade.

9.8  Attached hereto as Annex 1.1 is a description of the Transitional Services
     and related terms and conditions. Dade and Hoechst acknowledge and agree
     that Annex 1.1 may not reflect the understanding of the parties hereto and
     may, in particular, not be consistent with the representations and
     warranties made by Hoechst pursuant to Articles 1.1. 1.6, 1.8, 1.9 and 4.1
     herein. Dade and Hoechst agree that to the extent that Annex 1.1 is
     inconsistent with the terms of this Agreement, the terms of this Agreement
     shall govern. Dade and Hoechst shall amend Annex 1.1 such that the terms
     and conditions set forth therein shall be consistent with the terms and
     conditions set forth in this Agreement. Dade and Hoechst acknowledge and
     agree that nothing in Annex 1.1 shall modify, amend or otherwise effect the
     representations and warranties of Hoechst and the Service Entities set
     forth in this Agreement or the rights or remedies of Dade or any Acquired
     Entity hereunder.

                                      -16-
<PAGE>
 
IN WITNESS WHEREOF, the undersigned have executed this Agreement as of the date
first written above.

HOECHST AKTIENGESELLSCHAFT

also acting on behalf of the companies
listed in Annex A


By:     /s/                         By: 
   -----------------------------        ---------------------------
Name: --------------------------    Name:--------------------------
Title:--------------------------    Title:-------------------------


DIAGNOSTICS HOLDING, INC.

also acting on behalf of the companies
listed in Annex B


By:    /s/
    -----------------------------
Name-----------------------------
Title:---------------------------

                                      -17-