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                                  EXHIBIT 99.1


                            STOCK PURCHASE AGREEMENT


               This STOCK PURCHASE AGREEMENT dated as of June ___, 1998 (this
"Agreement") is made and entered into by and between Oaktree Capital Management,
LLC ("OCM") as agent and on behalf of certain funds and accounts listed on
Schedule I hereto (each such fund and account being referred to herein as a
"Purchaser" and collectively as the "Purchasers") and Nu-Tech Bio-Med, Inc.
("Seller").

               WHEREAS, Seller owns 1,315,000 shares of common stock, par value
$.01 per share ("Common Stock"), of Physicians Clinical Laboratory, Inc., a
Delaware corporation (the "Company"), constituting approximately 52.6% of the
issued and outstanding shares of capital stock of the Company as of the date
hereof (such shares being referred to herein as the "Shares"); and

               WHEREAS, Seller desires to sell, and Purchasers desire to
purchase, 67,500 of the Shares, constituting 2.7% of the issued and outstanding
shares of Common Stock, on the terms and subject to the conditions set forth in
this Agreement (the "Purchased Shares"), which will cause Purchasers and Seller
to hold the number of shares set forth opposite each such party's name on
Schedule II attached hereto.

               NOW, THEREFORE, in consideration of the mutual covenants and
agreements set forth in this Agreement, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto agree as follows:


                                   ARTICLE II

                           SALE OF SHARES AND CLOSING

               2.2 Purchase and Sale. Against receipt of the purchase price
provided in Section 1.2 hereof, Seller hereby sells, transfers and assigns to
each Purchaser all of the right, title and interest of Seller in and to the
number of Purchased Shares set forth opposite such Purchaser's name on Schedule
I attached hereto, and each Purchaser hereby purchases from the Sellers all of
such Purchased Shares.

               2.4 Purchase Price. The aggregate purchase price for the
Purchased Shares is $750,000 (the "Purchase Price"). Seller hereby acknowledges
receipt of the Purchase Price by wire transfer of immediately available funds.



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                                   ARTICLE IV

                    REPRESENTATIONS AND WARRANTIES OF SELLER

               Seller hereby represents and warrants to Purchasers as follows:

               4.2 Organization of Seller. Seller is a corporation duly
organized, validly existing and in good standing under the laws of the state of
its incorporation. Seller has full power and authority to execute and deliver
this Agreement and to perform its obligations hereunder and to consummate the
transactions contemplated hereby, including without limitation to own, hold,
sell and transfer (pursuant to this Agreement) the Purchased Shares.

               4.4 Title to Purchased Shares. Seller owns the Purchased Shares,
and is the sole record and beneficial owner of such Purchased Shares, free and
clear of all Liens. The delivery of a certificate or certificates representing
the Purchased Shares, in genuine and unaltered form, duly endorsed in blank or
accompanied by duly executed stock powers endorsed in blank will transfer to
Purchasers good and valid title to the Purchased Shares, free and clear of all
Liens (except such as may be imposed on the Purchased Shares by the Purchasers).

               4.6 Authority. The execution and delivery by Seller of this
Agreement and the performance by Seller of its obligations hereunder have been
duly and validly authorized, no other action on the part of Seller or its
stockholders being necessary. This Agreement has been duly and validly executed
and delivered by Seller and constitutes a legal, valid and binding obligation of
Seller enforceable against Seller in accordance with its terms, except to the
extent such enforceability may be limited by (i) bankruptcy, insolvency,
reorganization, moratorium or other similar laws relating to or affecting
generally the enforcement of creditors' rights and (ii) the availability of
equitable remedies (whether in a proceeding in equity or at law).

               4.8 No Conflicts. The execution and delivery by Seller of this
Agreement do not, and the performance by Seller of its obligations under this
Agreement and the consummation of the transactions contemplated hereby will not:

               (a) conflict with or result in a violation or breach of any of
the terms, conditions or provisions of the certificate or articles of
incorporation or by-laws (or other comparable organizational documents) of
Seller;

               (b) conflict with or result in a violation or breach of any term
or provision of any Law or Order applicable to Seller or the Purchased Shares;
or

               (c) (i) conflict with or result in a violation or breach of, (ii)
constitute (with or without notice or lapse of time or both) a default under,
(iii) require Seller to obtain any consent from any Person as a result or under
the terms of, or (iv) result in the creation or imposition of



                                  EXH. 99.1 - 2
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any Lien (other than such Liens as may be created by this Agreement) upon Seller
or the Purchased Shares under, any Contract to which Seller is a party.

               4.10 Governmental Approvals and Filings. No consent, approval or
action of, filing with or notice to any Governmental or Regulatory Authority on
the part of Seller is required in connection with the execution, delivery and
performance of this Agreement or the consummation of the transactions
contemplated hereby.

               4.12 Legal Proceedings. There are no Actions or Proceedings
pending or, to the knowledge of Seller, threatened against, relating to or
affecting Seller (or to the knowledge of Seller, the Company) which could
reasonably be expected to result in the issuance of an Order restraining,
enjoining or otherwise prohibiting or making illegal the consummation of any of
the transactions contemplated by this Agreement.

               4.14 Brokers. All negotiations relative to this Agreement and the
transactions contemplated hereby have been carried out by Seller directly with
Purchasers without the intervention of any Person on behalf of Seller in such
manner as to give rise to any valid claim by any Person against Purchasers or
the Company for a finder's fee, brokerage commission or similar payment.

               4.16 Agreements Relating to Shares. Other than documents listed
on Schedule 3.8 (the "Seller Agreements"), there are no (i) Contracts or other
arrangements concerning the acquisition, disposition or the voting of the
Purchased Shares, (ii) options with respect to the Purchased Shares, including
without limitation any form of preemptive rights or claims of third parties or
(iii) outstanding proxies, shareholder agreements, voting trusts, powers of
attorney or comparable delegations of authority concerning the Purchased Shares.
Each Seller Agreement is valid, binding and in full force and effect.


                                   ARTICLE VI

                  REPRESENTATIONS AND WARRANTIES OF PURCHASERS

               Each Purchaser, severally but not jointly, hereby represents and
warrants to Sellers as follows:

               6.2 Organization. Purchaser is a limited partnership duly
organized, validly existing and in good standing under the laws of its
jurisdiction of organization. Purchaser has full power and authority to execute
and deliver this Agreement, to perform its obligations hereunder and to
consummate the transactions contemplated hereby.

               6.4 Authority. The execution and delivery by Purchaser of this
Agreement, and the performance by Purchaser of its obligations hereunder, have
been duly and validly authorized,



                                  EXH. 99.1 - 3
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no other action on the part of Purchaser, its general partner or their
respective partners and members being necessary. This Agreement has been duly
and validly executed and delivered by Purchaser and constitutes a legal, valid
and binding obligation of Purchaser enforceable against Purchaser in accordance
with its terms, except to the extent such enforceability may be limited by (i)
bankruptcy, insolvency, reorganization, moratorium or other similar laws
relating to or affecting generally the enforcement of creditors' rights and (ii)
the availability of equitable remedies (whether in a proceeding in equity or at
law).

               6.6 No Conflicts. The execution and delivery by Purchaser of this
Agreement do not, and the performance by Purchaser of its obligations under this
Agreement and the consummation of the transactions contemplated hereby will not:

               (a) conflict with or result in a violation or breach of any of
the terms, conditions or provisions of the partnership agreement, articles of
organization or operating agreement (or other comparable organizational
documents) of Purchaser or its general partner;

               (b) conflict with or result in a violation or breach of any term
or provision of any Law or Order applicable to Purchaser;

               (c) (i) conflict with or result in a violation or breach of, (ii)
constitute (with or without notice or lapse of time or both) a default under, or
(iii) require Purchaser to obtain any consent from any Person as a result or
under the terms of, any Contract to which Purchaser is a party.

               6.8 Governmental Approvals and Filings. No consent, approval or
action of, filing with or notice to any Governmental or Regulatory Authority on
the part of Purchaser is required in connection with the execution, delivery and
performance of this Agreement or the consummation of the transactions
contemplated hereby.

               6.10 Legal Proceedings. There are no Actions or Proceedings
pending or, to the knowledge of Purchaser, threatened against, relating to or
affecting Purchaser which could reasonably be expected to result in the issuance
of an Order restraining, enjoining or otherwise prohibiting or making illegal
the consummation of any of the transactions contemplated by this Agreement.

               6.12 Purchase for Investment. The Purchased Shares will be
acquired by Purchaser (or, if applicable, its permitted assigns hereunder) for
its own account for the purpose of investment, it being understood that the
right to dispose of such Purchased Shares shall be entirely within the
discretion of Purchaser (or such assignee, as the case may be) subject to the
Amended and Restated Stockholders dated as of even date herewith by and among
the Company, OCM as agent and on behalf of the Purchasers, the Seller and J.
Marvin Feigenbaum ("Stockholders Agreement").



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               6.14 Brokers. All negotiations relative to this Agreement and the
transactions contemplated hereby have been carried out by Purchaser directly
with Sellers without the intervention of any Person on behalf of Purchaser in
such manner as to give rise to any valid claim by any Person against Sellers or
the Company for a finder's fee, brokerage commission or similar payment.


                                  ARTICLE VIII

                             REPRESENTATIONS OF OCM


               OCM represents that it has full power and authority to execute
and deliver this Agreement on behalf of the Purchasers, that the execution and
delivery by OCM of this Agreement on behalf of the Purchasers have been duly and
validly authorized and this Agreement constitutes the legal, valid and binding
obligation of Purchasers enforceable in accordance with its terms, except to the
extent such enforceability may be limited by (i) bankruptcy, insolvency,
reorganization, moratorium or other similar laws relating to or affecting
generally the enforcement of creditors' rights and (ii) the availability of
equitable remedies (whether in a proceeding in equity or at law).




                                    ARTICLE X

                                  DEFINED TERMS

               10.2 Definitions. (a) Defined Terms. As used in this Agreement,
the following defined terms have the meanings indicated below:

               "Actions or Proceedings" means any action, suit, proceeding,
arbitration or Governmental or Regulatory Authority investigation or audit.

               "Business Day" means a day other than Saturday, Sunday or any
other day on which banks located in the State of New York are authorized or
obligated to close.

               "Company" means Physician's Clinical Laboratory, Inc., a Delaware
corporation. Unless the context requires otherwise, all references to the
Company herein shall be deemed to include all of the consolidated subsidiaries
of the Company.

               "Contract" means any agreement, lease, license, evidence of
indebtedness, mortgage, indenture, security agreement or other contract (whether
written or oral).



                                  EXH. 99.1 - 5
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               "Governmental or Regulatory Authority" means any court, tribunal,
arbitrator, authority, agency, commission, official or other instrumentality of
the United States, any foreign country or any domestic or foreign state, county,
city or other political subdivision.

               "Law" means all laws, statutes, rules, regulations, ordinances
and other pronouncements having the effect of law of the United States, any
foreign country or any domestic or foreign state, county, city or other
political subdivision or of any Governmental or Regulatory Authority.

               "Liens" means any mortgage, pledge, assessment, security
interest, lease, lien, adverse claim, levy, charge or other encumbrance of any
kind, or any conditional sale Contract, title retention Contract or other
Contract to give any of the foregoing.

               "Order" means any writ, judgment, decree, injunction or similar
order of any Governmental or Regulatory Authority (in each such case whether
preliminary or final).

               "Person" means any natural person, corporation, general
partnership, limited partnership, proprietorship, other business organization,
trust, union, association or Governmental or Regulatory Authority.


                                   ARTICLE XII

                                  MISCELLANEOUS

               12.2 Further Assurances. Sellers and Purchasers shall execute and
deliver such other documents and instruments (including officers' certificates
and opinions of counsel), provide such materials and information and take such
other actions as may be reasonably requested to cause such party to fulfill its
obligations under this Agreement.

               12.4 Assignment. Subject to applicable securities laws and the
provisions of the Stockholders Agreement, Purchasers may assign their rights
pursuant to this Agreement without obtaining any consent of the Seller. Seller
may not assign any of its rights or obligations pursuant to this Agreement to
any Person without the prior written consent of the Purchasers.

               12.6 Indemnification. Each of the Seller on the one hand, and the
Purchasers, severally and not jointly, on the other, shall indemnify the other
party hereto, and its respective officers, directors, employees, agents and
Affiliates, in respect of, and hold each of them harmless from and against, any
and all losses, damages, fines, fees, penalties, deficiencies and expenses
(including court costs and reasonable attorneys' fees of the prevailing party in
any dispute), or of any claim, default or assessment, incurred or sustained by
any of them or to which any of them becomes subject relating to any breach by it
of a representation or warranty or nonperformance by it of any covenant or
agreement in this Agreement. A party seeking



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indemnification shall provide reasonable notice to the other party of its, or a
third party's, claim and give the other party the reasonable opportunity to
participate in resolution of the dispute. A party seeking indemnification shall
not be entitled to indemnification to the extent the other party is prejudiced
by a failure to provide such reasonable notice or opportunity to participate.

               12.8 Survival. Except for the representations and warranties of
Seller set forth in Section 2.2 and 2.3 which shall survive indefinitely, all
warranties, representations and covenants made by each of the Seller and the
Purchasers herein or in any certificate or other instrument delivered by it or
on its behalf under this Agreement shall be considered to have been relied upon
by the other party hereto and shall survive the consummation of the transactions
contemplated hereby for a period of two years regardless of any investigation
made by or on behalf of the other party hereto. All statements in any such
certificate or other instrument so delivered shall constitute representations
and warranties by the parties hereunder.

               12.10 Notices. All communication under this Agreement shall be in
writing and shall be personally delivered, sent by facsimile transmission or
mailed by first class mail, postage prepaid:

                      i)     if to the Seller

                             NU-TECH BIO-MED, INC.
                             Attn: Mr. J. Marvin Feigenbaum
                             476 Main Street
                             Wakefield, Rhode Island  02879
                             Fax:  401-789-9934

                      ii)    if to the Purchasers, to

                             OAKTREE CAPITAL MANAGEMENT, LLC
                             Attn: Mr. Matthew Barrett
                             550 S. Hope Street, 22nd Floor
                             Los Angeles, California  90071
                             Fax:  213-694-1599

or at such other address as the appropriate party to this Agreement may have
furnished in writing to each other party hereto.

Any notice shall be deemed to have been duly given when delivered by hand if
personally delivered, by confirmation of completed facsimile transmission if
delivered by facsimile, and if sent by mail, two (2) Business Days after being
deposited in the mail, postage prepaid.



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               12.12 Entire Agreement. This Agreement supersedes all prior
discussions and agreements between the parties with respect to the subject
matter hereof, and contains the sole and entire agreement between the parties
hereto with respect to the subject matter hereof.

               12.14 Amendment. This Agreement may be amended, supplemented or
modified only by a written instrument duly executed by or on behalf of each
party hereto.

               12.16 Governing Law. This Agreement shall be governed by and
construed in accordance with the laws of the State of New York applicable to a
Contract executed and performed in such State, without giving effect to the
conflicts of laws principles thereof.

               12.18 Counterparts. This Agreement may be executed in any number
of counterparts, each of which will be deemed an original, but all of which
together will constitute one and the same instrument.

               12.20 Limitation of Liability. Each of the parties hereto
acknowledges that in no event shall any of the partners, officers, directors,
shareholders, employees, agents, affiliates or investment managers (collectively
"Representatives") of OCM, as agent and on behalf of the funds and accounts set
forth on Schedule I attached hereto (the "Funds"), have any obligation or
liability to such party for any action taken or omitted by or on behalf of such
Funds or in connection herewith (such obligation and liability being the sole
responsibility of such Funds). Each party hereto further acknowledges and agrees
that (a) all obligations and liabilities of each Fund under this Agreement or in
connection herewith are enforceable solely against such Fund and its assets and
not against the assets of OCM, any other Fund or any Representatives of OCM and
(b) the obligations and liabilities of each Fund shall be several in the
proportions set forth on Schedule I hereto and not joint and several.



                                  EXH. 99.1 - 8
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               IN WITNESS WHEREOF, this Agreement has been duly executed and
delivered by the duly authorized officer of each party hereto as of the date
first above written.


                                          NU-TECH BIO-MED, INC.



                                          ------------------------------
                                          Name:
                                          Title:


                                          OAKTREE CAPITAL MANAGEMENT,
                                          LLC, as agent and on behalf of certain
                                          funds and accounts



                                          ------------------------------
                                          Name:
                                          Title:



                                          ------------------------------
                                          Name:
                                          Title:



                                  EXH. 99.1 - 9
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                                   SCHEDULE I

                               FUNDS AND ACCOUNTS





                                               
OCM Opportunities Fund, L.P.                    54.0%

Columbia/HCA Master Retirement Trust             4.0%
        (Separate Account I)

OCM Opportunities Fund II, L.P.                 41.0%

Columbia/HCA Master Retirement Trust             1.0%
        (Separate Account II)




                                 EXH. 99.1 - 10
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                                   SCHEDULE II





STOCKHOLDER                                                      SECURITIES
- -----------                                                      ----------

                                                                    
Nu-Tech Bio-Med, Inc.                                            1,247,500

OCM Opportunities Fund, L.P.

Columbia/HCA Master Retirement Trust
        (Separate Account I)

OCM Opportunities Fund II, L.P.

Columbia/HCA Master Retirement Trust
        (Separate Account II)




                                 EXH. 99.1 - 11