<PAGE>

4.15   REVOLVING CREDIT, TERM LOAN AND SECURITY AGREEMENT BY AND BETWEEN
       SERACARE, INC., AVRE INCORPORATED, BINARY ASSOCIATES, INC., SERACARE
       ACQUISITIONS, INC., BHM LABS, INC., SERACARE TECHNOLOGY, INC.,WESTERN
       STATES GROUP, INC., AMERICAN PLASMA, INC. ("OBLIGORS") AND BROWN
       BROTHERS HARRIMAN & CO. AND STATE STREET BANK AND TRUST COMPANY
       ("LENDERS") AND BROWN BROTHERS HARRIMAN & CO. AS ADMINISTRATIVE AGENT
       FOR LENDERS DATED DECEMBER 21, 1998.

<PAGE>

                  REVOLVING CREDIT, TERM LOAN AND SECURITY AGREEMENT

     This REVOLVING CREDIT, TERM LOAN AND SECURITY AGREEMENT entered into at
Boston, Massachusetts, as of December 21, 1998, between SERACARE, INC., a
California corporation with an address of 1925 Century Park East, Suite 1970,
Los Angeles, California 90067 (the "Borrower"); AVRE INCORPORATED, a Nevada
corporation with an address of 1925 Century Park East, Suite 1970, Los
Angeles, California 90067 ("Avre"); BINARY ASSOCIATES, INC., a Colorado
corporation with an address of 1925 Century Park East, Suite 1970, Los
Angeles, California 90067 ("Binary"); SERACARE ACQUISITIONS, INC., a Nevada
corporation with an address of 1925 Century Park East, Suite 1970, Los
Angeles, California 90067 ("Acquisitions"); BHM LABS, INC., an Arkansas
corporation with an address of 1925 Century Park East, Suite 1970, Los
Angeles, California 90067 ("BHM"); SERACARE TECHNOLOGY, INC., a Nevada
corporation with an address of 2170 Woodward, Austin, Texas 78744
("Technology"); THE WESTERN STATES GROUP, INC., a California corporation with
an address of 1935 Avenida del Oro, Suite F, Oceanside, California 92056
("Western"); AMERICAN PLASMA, INC., a Texas corporation with an address of
719 Sawdust Road, Suite 205, Spring, Texas 77380 and with an address after
December 31, 1998 of 1925 Century Park East, Suite 1970, Los Angeles,
California 90067 ("American Plasma," and along with the Borrower, Avre,
Binary, Acquisitions, BHM, Technology and Western, each an "Obligor" and
collectively, the "Obligors"); and BROWN BROTHERS HARRIMAN & CO., a New York
general partnership with an address of 40 Water Street, Boston, Massachusetts
02109 ("BBH"); STATE STREET BANK AND TRUST COMPANY, a Massachusetts trust
company with an address of 225 Franklin Street, Boston, Massachusetts 02110
("State Street") (BBH and State Street hereinafter are collectively referred
to as "Lenders" and sometimes individually as a "Lender"); and BROWN BROTHERS
HARRIMAN & CO. AS ADMINISTRATIVE AGENT for the Lenders, with an address of 40
Water Street, Boston, Massachusetts 02109 (the "Administrative Agent").

     THIS REVOLVING CREDIT, TERM LOAN AND SECURITY AGREEMENT AMENDS AND
RESTATES IN ITS ENTIRETY THAT CERTAIN AMENDED AND RESTATED REVOLVING LOAN AND
SECURITY AGREEMENT DATED AS OF SEPTEMBER 29, 1998, AMONG THE OBLIGORS AND BBH.

     FOR VALUE RECEIVED, and in consideration of the granting by the Lenders
of financial accommodations to Obligors, and the mutual covenants and
agreements herein contained, each Obligor, the Administrative Agent and the
Lenders, as of the date hereof and as of the date of each credit and/or other
financial accommodation, agree as follows:


                              1. THE REVOLVING LOAN

1.1    REVOLVING LOAN. Lenders agree to establish a revolving line of credit
for Borrower of up to Ten Million Dollars ($10,000,000) (the "Revolving Loan
Amount") which shall expire on December 1, 2000 (the "Revolving

<PAGE>

Loan"). Subject to the terms and conditions set forth herein, and in reliance
upon the representations, warranties and covenants of the Borrower made
herein, each Lender severally agrees to lend to the Borrower from time to
time through the Administrative Agent upon the Borrower's request its
respective pro-rata share (as set forth in EXHIBIT A attached hereto) of the
amounts of advances requested by the Borrower under the Revolving Loan such
that the aggregate principal amount outstanding under the Revolving Loan
shall not exceed at any time the amount of the lesser of (a) the Revolving
Loan Amount and (b) the Borrowing Base, as such term is hereinafter defined
and as calculated in a borrowing base certificate in the form of EXHIBIT B
attached hereto and delivered to the Administrative Agent and each Lender
simultaneously with the execution and delivery of this Agreement and monthly
on or before the 20th day of each month (with respect to the prior month),
commencing January 1, 1999. The Borrower shall make all requests for advances
under the Revolving Loan to the Administrative Agent not later than 1:00 p.m.
(Boston, Massachusetts time) on the Business Day (as hereinafter defined)
immediately preceding the date on which the Borrower desires to receive the
advance. Each request by the Borrower for an advance under the Revolving Loan
shall specify the amount and date of such advance. "Business Day" means any
day other than a Saturday, Sunday or federal or Massachusetts holiday on
which banks in Boston, Massachusetts are open for the conduct of a
substantial part of their commercial banking business. Advances under the
Revolving Loan may only be made on a Business Day. The failure or delay by a
Lender to make available its pro-rata share of any advance requested by
Borrower under the Revolving Loan shall not relieve the other Lender of its
obligation, if any, to make available its pro-rata share of such advance. In
no event, however, shall a Lender, or the Administrative Agent, be
responsible for the failure of the other Lender to make available any portion
of such an advance. The Revolving Loan is evidenced by (1) that certain
Amended and Restated Revolving Term Note of even date herewith by the
Borrower in favor of BBH in the face amount of $5,000,000 (the "BBH Revolving
Note") and (2) that certain Revolving Term Note of even date herewith by the
Borrower in favor of State Street in the face amount of $5,000,000 (the
"State Street Revolving Note") (the BBH Revolving Note and State Street
Revolving Note are hereinafter together referred to as the "Revolving Note").
This Agreement, the Revolving Note, the Term Note (as hereinafter defined)
and any and all other documents, amendments and renewals executed and
delivered in connection with any of the foregoing are collectively
hereinafter referred to as the "Loan Documents."

1.2    REVOLVING LOAN ACCOUNT. An account shall be opened on the books of the
Administrative Agent which shall be designated on the Administrative Agent's
books and records as Borrower's "Revolving Loan Account," in which account a
record will be kept of all loans and other advances made by Lenders to
Borrower respecting the Revolving Loan, and all payments thereon and other
appropriate debits and credits as provided by this Agreement. Each loan made
hereunder by a Lender shall be made in accordance with this Agreement and may
be credited by the Administrative Agent to any deposit account of Borrower
with such Lender, or may be paid to Borrower, or may be applied to any
Obligations (as hereinafter defined), as such Lender may in each instance
elect.

1.3    INTEREST. Interest will be charged to Borrower on the principal amount
of the Revolving Loan from time to time outstanding at the rate specified in
the Revolving Note in accordance with the terms of the Revolving Note.
Interest shall be payable quarterly in arrears in accordance with the terms
of the Revolving Note.

1.4    COMMITMENT AND FACILITY FEES. In addition to all other fees and
expenses due to Lenders respecting the Revolving Loan, Borrower shall pay to
the Administrative Agent for payment ratably to the Lenders (i)
simultaneously with the execution and delivery of this Agreement, a facility
fee equal to $60,000 and (ii) quarterly in arrears on the first business day
of each calendar quarter commencing January 1, 1999, an unused commitment fee
equal to an amount calculated by multiplying .000625 by the difference
between the Revolving Loan Amount and the average daily balance outstanding
respecting the Revolving Loan during the prior calendar quarter.

1.5    REPAYMENT. All loans and advances made by Lenders to Borrower under or
pursuant to this Agreement respecting the Revolving Loan shall be payable to
the Administrative Agent for the ratable account of the Lenders on or before
the maturity date of the Revolving Note unless otherwise agreed to in writing
by the Borrower and the Lenders and so long as there are no uncured Events of
Default (as hereinafter defined). The Borrower will make payments of
principal under the Revolving Loan from time to time so that the aggregate
outstanding principal balance of the Revolving Loan does not exceed the
lesser of the Borrowing Base (as hereinafter defined) and the Revolving Loan
Amount at any time.

                                       2
<PAGE>

1.6    ADDITIONAL LOANS. Any loans, advances and credits to the Borrower that
are made in excess of the Revolving Loan Amount for the line of credit
established hereunder shall not affect the obligations of Borrower or any of
the Administrative Agent's or Lenders' rights or remedies hereunder or under
the Loan Documents or otherwise, such loans and all loans hereunder to be
secured by the Collateral (as hereinafter defined) and to be due and payable
to the Administrative Agent upon the same terms as the Revolving Loan Amount
pursuant to the Revolving Note, and shall bear interest at the rate set forth
in the Revolving Note unless otherwise agreed to in writing. All checks or
other items paid by a Lender which cause an overdraft in any deposit account
maintained by Borrower with such Lender shall constitute an advance to
Borrower pursuant to this Agreement, repayable on demand, and shall be
secured by all Collateral at any time pledged by Borrower to such Lender.

1.7    AUTHORIZED PERSONS. Any person duly authorized by a general borrowing
resolution of the Borrower, or in the absence of such a resolution, the
President, Chief Financial Officer, Treasurer or any Vice President of the
Borrower, may request discretionary loans hereunder, either orally or
otherwise, but the Lenders at their option may require that all requests for
loans hereunder shall be in writing. Each of the Lenders and the
Administrative Agent shall incur no liability to the Borrower in acting upon
any request referred to herein which it believes in good faith to have been
made by an authorized person or persons.

1.8    MONTHLY STATEMENT. At the option of the Administrative Agent, after
the end of each month, Administrative Agent will render to Borrower a
statement of Borrower's Revolving Loan Account with Administrative Agent,
showing all applicable credits and debits. Each statement shall be considered
correct and to have been accepted by Borrower and shall be conclusively
binding upon Borrower in respect of all charges, debits and credits of
whatsoever nature contained therein respecting the Revolving Loan, and the
closing balance shown therein, unless Borrower notifies Administrative Agent
in writing of any discrepancy within twenty (20) days from the receipt by the
Borrower of any such monthly statement.


                                  2. TERM LOAN

2.1    TERM LOAN. Upon the terms and subject to the conditions of this
Agreement, and in reliance upon the representations, warranties and covenants
of the Borrower made herein, the Lenders agree to lend to the Borrower the
principal sum of $7,000,000 (the "Term Loan Amount") on the date hereof. Such
loan (the "Term Loan") is evidenced by (1) that certain Term Promissory Note
of even date herewith by the Borrower in favor of BBH in the principal amount
of $3,500,000 (the "BBH Term Note") and (2) that certain Term Promissory Note
of even date herewith by the Borrower in favor of State Street in the
principal amount of $3,500,000 (the "State Street Term Note") (the BBH Term
Note and State Street Term Note are hereinafter together referred to as the
"Term Note"). Each Lender's respective pro-rata share of the Term Loan Amount
is set forth in attached EXHIBIT A.

2.2    INTEREST. Interest will be charged to Borrower on the principal amount
of the Term Loan from time to time outstanding at the rate specified in the
Term Note in accordance with the terms of the Term Note. Interest shall be
payable quarterly in arrears in accordance with the terms of the Term Note.

2.3    REPAYMENT. The Term Loan Amount shall be payable to the Administrative
Agent for the ratable account of the Lenders over an approximate three-year
period ending December 1, 2001 in accordance with the terms of the Term Note
unless otherwise agreed to in writing by the Borrower and the Lenders and so
long as there are no uncured Events of Default (as hereinafter defined).

2.4    PREPAYMENT. The Term Loan may be prepaid in whole or in part without
premium or penalty, provided that the Borrower shall also pay accrued
interest on the principal so prepaid to the date of such prepayment and all
fees and charges payable on or before the date of such prepayment. Mandatory
and voluntary prepayments shall be applied against unpaid installments of
principal of the Term Loan in inverse order of maturity of such installments.
The Borrower shall not be permitted to reborrow any part of the principal of
the Term Loan so prepaid at any time or under any circumstances.

                                      3
<PAGE>

             3. MANNER OF PAYMENT UNDER REVOLVING LOAN AND TERM LOAN

3.1    All payments of principal, interest, fees and any other amounts due
hereunder or under any of the other Loan Documents shall be made to the
Administrative Agent for the ratable account of the Lenders at the
Administrative Agents office at 40 Water Street, Boston, Massachusetts 02109,
or at such other location as the Administrative Agent may from time to time
designate in writing, in each case in United States Dollars constituting
immediately available funds.


                           4. GRANT OF SECURITY INTEREST

4.1    GRANT OF SECURITY INTEREST. In consideration of the Lenders' extending
credit and other financial accommodations to the Obligors, each Obligor
hereby grants to the Administrative Agent for the ratable benefit of the
Administrative Agent and the Lenders a security interest in (including,
without limitation, a lien on and pledge of) all of such Obligor's Collateral
(as hereinafter defined). The security interest granted by this Agreement is
given to and shall be held by the Administrative Agent for the ratable
benefit of the Administrative Agent and the Lenders as security for the
payment and performance of all Obligations (as hereinafter defined).

4.2    DEFINITIONS. The following definitions shall apply:

       (a)     "Accounts Receivable" means all of an Obligor's accounts,
               accounts receivable, contract rights, notes, bills, drafts,
               acceptances, instruments, documents, chattel paper and all other
               debts, obligations and liabilities in whatever form owing to an
               Obligor from any Person (as defined below) for goods sold by it
               or for services rendered by it, or however otherwise established
               or created, all guaranties and security therefor, all right,
               title and interest of an Obligor in the goods or services which
               gave rise thereto, including rights to reclamation and stoppage
               in transit and all rights of any unpaid seller of goods or
               services; whether any of the foregoing be now existing or
               hereafter arising, now or hereafter received by or owing or
               belonging to an Obligor.

       (b)     "Borrowing Base" as used in this Agreement means the lesser of
               (i) the sum of seventy-five percent (75%) of the Obligors'
               Accounts Receivable (excluding (1) all Accounts Receivable owed
               by a Debtor (as hereinafter defined) in respect of which there
               has been established a contra account or against which an offset,
               charge or lien has been claimed or asserted by such Debtor, to
               the extent of such account, offset, charge or lien, (2) all
               Accounts Receivable owed by a Debtor as to which any Obligor has
               received notice or has knowledge of bankruptcy, insolvency or
               other facts which make collection doubtful or have been turned
               over to a collection agency or an attorney for collection, (3)
               all Accounts Receivable that are greater than ninety (90) days
               from the invoice date, and (4) those foreign Accounts Receivable
               which when added to all other foreign Accounts Receivable would
               cause the sum of the foreign Accounts Receivable to exceed
               twenty-five percent (25%) of the Obligors' Accounts Receivable)
               plus the lesser amount of (A) fifty percent (50%) of the
               Obligors' Inventory (as hereinafter defined) and (B) $7,500,000,
               and (ii) the Revolving Loan Amount. For purposes of clause 4
               above, Accounts Receivable that are due from Grifols, S.A. or are
               backed by a letter of credit (to the extent so backed) shall be
               deemed not to be foreign Accounts Receivable.

       (c)     "Code" shall mean the Massachusetts Uniform Commercial Code
               (General Law, Chapter 106) as amended from time to time.

       (d)     "Collateral" shall mean all of each Obligor's present and future
               right, title and interest in and to any and all of the following
               property, whether such property is now existing or hereafter
               created:

               (i)    All goods, including, without limitation, all Inventory
               (as hereinafter defined), farm products, Equipment (as
               hereinafter defined), including, without limitation, all
               machinery, furniture, and trade fixtures;

               (ii)   All accounts, Accounts Receivable, contract rights and
               chattel paper, regardless of whether or not they constitute
               proceeds of other Collateral;

                                      4
<PAGE>

               (iii)  All investment property, including, without limitation,
               all securities (including, but not limited to, all of the
               Borrower's stock of its subsidiaries) whether certificated or
               uncertificated, all securities entitlements, securities accounts,
               commodity contracts or commodity accounts;

               (iv)   All general intangibles, regardless of whether or not
               they constitute proceeds of other Collateral, including, without
               limitation, all of an Obligor's rights to tax refunds and all of
               an Obligor's rights (which a Lender may exercise or not as it in
               its sole discretion may determine) to acquire or obtain goods
               and/or services with respect to the manufacture, processing,
               storage, sale, shipment, delivery or installation of any of an
               Obligor's Inventory (as hereinafter defined) or other Collateral;

               (v)    All products of and accessions to any of the Collateral;

               (vi)   All liens, guaranties, securities, rights, remedies and
               privileges pertaining to any of the Collateral, including the
               right of stoppage in transit;

               (vii)  All obligations owing to an Obligor of every kind and
               nature; and all choices in action;

               (viii) All goodwill, trade secrets, computer programs, customer
               lists, copyrights, trade names, trademarks and patents;

               (ix)   All documents and instruments (whether negotiable or
               nonnegotiable, and regardless of their being attached to chattel
               paper);

               (x)    All proceeds of Collateral of every kind and nature in
               whatever form, including, without limitation, both cash and
               noncash proceeds resulting or arising from the rendering of
               services by an Obligor or the sale or other disposition by an
               Obligor of the Inventory (as hereinafter defined) or other
               Collateral;

               (xi)   All books and records relating to the conduct of an
               Obligor's business including, without in any way limiting the
               generality of the foregoing, those relating to its accounts; and

               (xii)  All deposit accounts maintained by an Obligor with any
               Lender, trust company, investment firm or fund, or any similar
               institution or organization.

       (e)     "Contract Rights" or "contract rights" means rights of an Obligor
               to payment under contracts not yet earned by performance and not
               evidenced by instruments or chattel paper.

       (f)     "Debtors" shall mean an Obligor's customers who are indebted to
               the Obligor.

       (g)     "Equipment" shall mean and include all of an Obligor's machinery,
               equipment, furniture, trade fixtures and motor vehicles and
               intending to include all tangible personal property, or goods,
               utilized in the conduct of an Obligor's business, but excluding
               therefrom inventory, as that term is defined in the Code, and all
               replacements or substitutions therefor and all accessions
               thereto.

       (h)     "Inventory" means all inventory of whatever name, nature, kind or
               description, all goods held for sale or lease or to be furnished
               under contracts of service, finished goods, work in process, raw
               materials, materials used or consumed by an Obligor, parts,
               supplies, all wrapping, packaging, advertising labeling, and
               shipping materials, devices, names and marks, all contract rights
               and documents relating to any of the foregoing, whether any of
               the foregoing be now existing or hereafter arising, wherever
               located, now owned or hereafter acquired by an Obligor.

       (i)     "Obligation(s)" shall mean, without limitation, all loans,
               advances, indebtedness, notes, liabilities and amounts,
               liquidated or unliquidated, owing by the Obligors to the Lenders
               and the Administrative Agent at any time, of each and every kind,
               nature and description, whether arising under this Agreement or
               otherwise, and whether secured or unsecured, direct or indirect
               (that is, whether the same are due directly by an Obligor to a
               Lender or the Administrative Agent; or are due indirectly by an
               Obligor to a Lender or the Administrative Agent as endorser,
               guarantor or other surety, or as a borrower of obligations due
               third persons which have been endorsed or assigned to a Lender or
               the Administrative Agent or otherwise), absolute or contingent,
               due or to become due, now existing or hereafter contracted. Said
               term shall also include all interest and other charges chargeable
               to an Obligor or due from an Obligor to a Lender or the
               Administrative Agent from time to time and all costs and expenses
               referred to in this Agreement.

                                      5
<PAGE>

       (j)     "Permitted Investments" shall mean (i) direct obligations of the
               United States, or obligations guaranteed as to principal and
               interest by the United States government, (ii) bankers'
               acceptances and certificates of deposit issued by any bank or any
               other bank or trust company or, in the case of any subsidiary
               bank of a bank holding company, a bank holding company, having
               capital, surplus and undivided profits of at least $500,000,000,
               the short-term deposits of which are given an A1 or P1 rating by
               Standard & Poor's Rating Group or Moody's Investors Service,
               Inc., as applicable, (iii) obligations of any bank or trust
               company or bank holding company described in clause (ii) above in
               respect of the repurchase of obligations of the type described in
               clause (i) hereof, provided that such repurchase obligations
               shall be fully secured by obligations of the type described in
               said clause (i) and the possession of such obligations shall be
               transferred to, and segregated from other obligations owned by,
               any such bank, trust company or bank holding company, (iv)
               commercial paper given a rating of A1 or P1 by Standard & Poor's
               Ratings Group or Moody's Investors Service, Inc., as applicable
               and (v) money market funds organized under the laws of the United
               States or any state thereof that invest substantially all of
               their assets in any of the types of investments described in
               clauses (i), (ii), (iii) or (iv); PROVIDED, HOWEVER, that no such
               investment shall have a maturity longer than 270 days from the
               date of acquisition by an Obligor.

       (k)     "Person" or "party" shall include individuals, firms,
               corporations and all other entities.

       All words and terms used in this Agreement other than those
specifically defined herein shall have the meanings accorded to them in the
Code.

4.3    ORDINARY COURSE OF BUSINESS. The Lenders hereby authorize and permit
each Obligor to hold, process, sell, use or consume in the manufacture or
processing of finished goods, or otherwise dispose of for fair consideration,
the Inventory, all in the ordinary course of such Obligor's business,
excluding, without limitation, sales to creditors or in bulk or sales or
other dispositions occurring under circumstances which would or could create
any lien or interest adverse to the Lenders' security interest or other right
hereunder in the proceeds resulting therefrom. The Lenders also hereby
authorize and permit each Obligor to receive from Debtors all amounts due as
proceeds of the Collateral at the Obligor's own cost and expense, and also
liability, if any, in the ordinary course of business; and the Lenders or the
Administrative Agent may, so long as there is an existing uncured Event of
Default (as hereinafter defined), terminate all or any part of the authority
and permission herein or elsewhere in this Agreement granted to any such
Obligor with reference to the Collateral.

       Until the Administrative Agent shall otherwise notify an Obligor, all
proceeds of and collections of Collateral shall be retained by such Obligor
and used solely for the ordinary and usual operation of such Obligor's
business. From and after notice by the Administrative Agent to an Obligor,
all proceeds of and collections of the Collateral shall be held in trust by
such Obligor for the Administrative Agent and the Lenders and shall not be
commingled with such Obligor's other funds or deposited in any Lender account
of such Obligor; and such Obligor agrees to deliver to the Administrative
Agent on the dates of receipt thereof by such Obligor, duly endorsed to the
Administrative Agent for the ratable benefit of the Administrative Agent and
the Lenders, or to bearer, or assigned to the Administrative Agent for the
ratable benefit of the Administrative Agent and the Lenders, as may be
appropriate, all proceeds of the Collateral in the identical form received by
such Obligor.

4.4    ALLOWANCES. Each Obligor may grant such allowances or other
adjustments to Debtors (exclusive of extending the time for payment of any
item in excess of $50,000 which shall not be done without first obtaining the
Administrative Agent's written consent in each instance) as such Obligor may
reasonably deem to accord with sound business practice, including, without
limiting the generality of the foregoing, accepting the return of all or any
part of the Inventory.

4.5    RECORDS. Each Obligor shall deliver to the Administrative Agent and
the Lenders from time to time promptly at their reasonable request all
invoices, original documents of title, contracts, chattel paper, instruments
and any other writings relating thereto, and other evidence of performance of
contracts, or evidence of shipment or delivery of the merchandise or of the
rendering of services; and each Obligor will deliver to the Administrative
Agent and the Lenders promptly at their reasonable request from time to time
additional copies of any or all of such papers or writings, and such other
information with respect to any of the Collateral and such schedules of
Inventory, schedules of accounts and such other writings as the
Administrative Agent or Lenders may in their sole discretion

                                      6
<PAGE>

deem to be necessary or effectual to evidence any loan hereunder or the
Lenders' and Administrative Agent's security interest in the Collateral.

4.6     LEGENDS. Each Obligor shall promptly make, stamp or record such
entries or legends on such Obligor's books and records or on any of the
Collateral as the Administrative Agent shall reasonably request from time to
time, to indicate and disclose that the Lenders and Administrative Agent have
a security interest in such Collateral.

4.7    INSPECTION. The Administrative Agent and each Lender, or their
representatives, at any time and from time to time, but with at least one (1)
business day's notice, shall have the right, and each Obligor will permit
them at the Obligors' expense during normal business hours so long as there
is no existing uncured Event of Default under this Agreement or at any time
(with or without notice at Administrative Agent's or such Lender's option, as
applicable) if there is an existing uncured Event of Default:

       (a)     to examine, check, make copies of or extracts from any of the
               Obligor's books, records and files (including, without
               limitation, orders and original correspondence);

       (b)     to inspect, examine or appraise the Collateral and to check and
               test the same as to quality, quantity, value and condition; and

       (c)     to verify the Collateral or any portion or portions thereof or
               each Obligor's compliance with the provisions of this Agreement.


                         5. REPRESENTATIONS AND WARRANTIES

5.1    ORGANIZATION AND QUALIFICATION. Each Obligor is a duly organized and
existing corporation under the laws of the State of its incorporation, as
indicated above, in good standing under the laws of said state, and is duly
qualified to do business under the laws of each state where the nature of the
business done or property owned requires such qualification, except where the
failure to be so qualified would not have a material adverse affect on the
financial condition or results of operations of Obligors on a consolidated
basis.

5.2    SUBSIDIARIES. Each Obligor has no subsidiaries other than those listed
on SCHEDULE 5.2, if any, and each Obligor has never consolidated, merged or
acquired substantially all of the assets of any other entity or person other
than those listed on SCHEDULE 5.2, if any.

5.3    CORPORATE RECORDS. Each Obligor's Certificate of Incorporation and all
amendments thereto have been duly filed. All outstanding capital stock issued
by each Obligor was and is properly issued and all books and records of each
Obligor, including but not limited to its minute books, bylaws and books of
account, are accurate and up to date and will be so maintained.

5.4    TITLE TO PROPERTIES; ABSENCE OF LIENS. Except as set forth on SCHEDULE
5.4, each Obligor has good and clear record and marketable title to all of
its properties and assets, and all of its properties and assets including the
Collateral are free and clear of all mortgages, liens, pledges, charges,
encumbrances, setoffs, except (a) the mortgages and security interests as set
forth on SCHEDULE 5.4a, if any, and (b) the leases of personal property as
set forth on SCHEDULE 5.4b, if any.

5.5    PLACES OF BUSINESS. Each Obligor's chief executive office is correctly
stated in the preamble to this Agreement, and each Obligor shall, during the
term of this Agreement, keep the Administrative Agent currently and
accurately informed in writing of each of its other places of business, and
shall not change the location of such chief executive office or open or
close, move or change any existing or new place of business without giving
the Administrative Agent at least thirty (30) days prior written notice
thereof.

5.6    VALID OBLIGATIONS. The execution, delivery and performance of the Loan
Documents have been duly authorized by all necessary corporate action and
each represents a legal, valid and binding obligation of each Obligor and is
fully enforceable according to its terms, except as limited by laws relating
to the enforcement of creditors' rights and by general principles of equity.

5.7    CONFLICTS WITH OTHER AGREEMENTS. Except as set forth on SCHEDULE 5.7,
there is no provision in any indenture, contract or agreement to which any
Obligor is a party which prohibits the execution, delivery or performance of
the Loan Documents.

                                      7
<PAGE>

5.8    GOVERNMENTAL APPROVALS. The execution, delivery and performance of the
Loan Documents does not require any approval of any governmental agency or
authority and, except as set forth on SCHEDULE 5.8, each Obligor has obtained
all requisite licenses, franchises, permits, consents and other
authorizations which are material to operate its business as currently
conducted. All such licenses, franchises, permits, consents and
authorizations are readily assignable and transferable by the Obligors,
subject to approval by the applicable governmental agency or authority.

5.9    LITIGATION. There are no actions, suits or proceedings pending or to
the knowledge of any Obligor threatened against any Obligor which might
materially adversely affect the ability of any Obligor to perform its
obligations under the Loan Documents.

5.10   FINANCIAL STATEMENTS. The Obligors have furnished to the Lenders the
following financial statements (the "Financial Statements"): consolidated and
consolidating balance sheet as of August 31, 1998, and consolidated and
consolidating statement of profit and loss for the six-month period ending
August 31, 1998. The balance sheet fairly presents the condition of the
Obligors at the date thereof and the statement of profit and loss fairly
presents the results of the operations of the Obligors for the period
indicated, all in conformity with generally accepted accounting principles,
consistently applied.

5.11   ACCOUNTS AND CONTRACT RIGHTS. All of each Obligor's Accounts
Receivable arise out of legally enforceable and existing contracts; and
represent undisputed bona fide indebtedness by the Debtor for sales or leases
of Inventory shipped and delivered or services rendered by an Obligor to a
Debtor, and are not and will not be subject to any discount (except such cash
or trade discount as may be shown on any invoice, contract or other writing
in the ordinary course of business). No contract right, account, general
intangible or chattel paper is or will be represented by any note or other
instrument, and no contract right, account or general intangible is or will
be represented by any conditional or installment sales obligation or other
chattel paper, except such instruments or chattel paper as have been or
immediately upon receipt by an Obligor will be delivered to the
Administrative Agent (duly endorsed or assigned), such delivery, in the case
of chattel paper, to include all executed copies except those in the
possession of the installment buyer and any security for or guaranty of any
of the Collateral shall be delivered to the Administrative Agent immediately
upon receipt thereof by an Obligor, with such assignments and endorsements
thereof as the Administrative Agent may request.

5.12   TITLE TO COLLATERAL. Except as set forth in SCHEDULE 5.12, attached
hereto, or as otherwise permitted under this Agreement, (i) at the date
hereof each Obligor is (and as to Collateral that such Obligor may acquire
after the date hereof, will be) the lawful owner of the Collateral; (ii) the
Collateral and each item thereof is, will be and shall continue to be free of
all restrictions, liens, encumbrances or other rights, title or interests
(other than the security interest therein granted to the Administrative Agent
for the ratable benefit of the Administrative Agent and the Lenders hereby),
credits, defenses, recoupments, set-offs or counterclaims whatsoever; each
Obligor has and will have full power and authority to grant to the
Administrative Agent for the ratable benefit of the Administrative Agent and
the Lenders a security interest therein; (iii) each Obligor has not
transferred, assigned, sold, pledged, encumbered, subjected to lien or
granted any security interest in, and will not transfer, assign, sell (except
sales or other dispositions in the ordinary course of business in respect to
Inventory or as expressly permitted in this Agreement), pledge, encumber,
subject to lien or grant any security interest in, any of the Collateral (or
any of such Obligor's right, title or interest therein), to any person other
than the Administrative Agent for the ratable benefit of the Administrative
Agent and the Lenders; the Collateral is and will be valid and genuine in all
respects; (iv) the Accounts Receivable shall represent unconditional and
undisputed bona fide indebtedness by the Debtor for sales or leases of
Inventory shipped and delivered or services rendered by an Obligor to Debtor,
and is not and will not be subject to any discount (except such cash or trade
discount as may be shown on any invoice, contract or other writing in the
ordinary course of business); and (v) each Obligor will warrant and defend
the Lenders' right to and interest in the Collateral against all claims and
demands of all persons whatsoever.

5.13   LOCATION OF COLLATERAL. The Collateral is kept and maintained solely
at the locations set forth in SCHEDULE 5.13 attached hereto. Except for
sale, processing, use, consumption or other disposition of Inventory and
Equipment in the ordinary course of business, each Obligor will keep all
Collateral only at locations specified in SCHEDULE 5.13; each Obligor shall,
during the term of this Agreement, keep the Administrative Agent currently
and accurately informed in writing of each location where such Obligor's
records relating to its accounts and

                                      8
<PAGE>

contract rights, respectively, are kept, and shall not remove such records or
any of them to another state without giving the Administrative Agent at least
thirty (30) days prior written notice thereof.

5.14   THIRD PARTIES. The Administrative Agent and Lenders shall not be
deemed to have assumed any liability or responsibility to any Obligor or any
third person for the correctness, validity or genuineness of any instruments
or documents that may be released or endorsed to an Obligor by the
Administrative Agent or the Lenders (which shall automatically be deemed to
be without recourse to the Administrative Agent and Lenders in any event) or
for the existence, character, quantity, quality, condition, value or delivery
of any goods purporting to be represented by any such documents; and the
Administrative Agent and Lenders, by accepting such security interest in the
Collateral, or by releasing any Collateral to any Obligor, shall not be
deemed to have assumed any obligation or liability to any supplier or Debtor
or to any other third party, and each Obligor agrees to indemnify and defend
the Administrative Agent and Lenders and hold them harmless in respect to any
claim or proceeding arising out of any matter referred to in this paragraph.

5.15   PAYMENT OF ACCOUNTS. Upon becoming aware of any suspension of business,
assignment or trust mortgage for the benefit of creditors, dissolution,
petition in receivership or under any chapter of the Bankruptcy Code as
amended from time to time by or against any Debtor, any Debtor becoming
insolvent or unable to pay its debts as they mature or any other act of the
same or different nature amounting to a business failure, each Obligor will
forthwith notify the Administrative Agent and the Lenders thereof.

5.16   NOTIFICATION OF DAMAGE. Each Obligor will immediately notify the
Administrative Agent and the Lenders of any loss or damage to, or material
diminution in or any occurrence that would materially adversely affect the
value of the Inventory, the Equipment or other Collateral.

5.17   CHANGES. Since the date of the Financial Statements, there have been
no changes in the assets, liabilities, financial condition or business of any
Obligor, other than changes in the ordinary course of business, or relating
to the acquisition of American Plasma, Western and Consolidated Technologies,
Inc., or as set forth on SCHEDULE 5.17, or the issuance of the Company's 12%
senior subordinated debentures, the effect of which have, in the aggregate,
been materially adverse to the financial condition or results of operations
of the Obligors on a consolidated basis.

5.18   YEAR 2000. To each Obligor's knowledge, (i) no material modifications
are required to any of each Obligor's computer systems or computer software
to assure that such systems and software contain no deficiencies relating to
formatting for entering dates (commonly referred to and referred herein as
the "Year 2000 Problem"); (ii) each Obligor's computer systems and software
in all material respects are susceptible to all necessary modification and
each Obligor has adequate personnel or consultants UNDER CONTRACT or other
available means to timely modify (or, as applicable, replace and/or upgrade)
its own computer systems and software. Each Obligor is not aware of any
inability on the part of any of its customers, insurance providers or vendors
to timely address the Year 2000 Problem that will in any manner materially
adversely affect such Obligor's business operations.

5.19   TAXES. Each Obligor has filed or is in the process of filing all
Federal, state and other tax returns required to be filed (except for such
returns for which current and valid extensions have been filed), and all
taxes, assessments and other governmental charges due from each Obligor have
been fully paid. Each Obligor has established on its books reserves adequate
for the payment of all Federal, state and other tax liabilities (if any).

5.20   USE OF PROCEEDS. No portion of the Revolving Loan or Term Loan is to
be used for the purpose of purchasing or carrying any "margin security" or
"margin stock" as such terms are used in Regulations G and U of the Board of
Governors of the Federal Reserve System, 12 C.F.R. 207 and 221. The proceeds
of the Revolving Loan are to be used for working capital and to finance
acquisitions; the proceeds of the Term Loan are to be used for the
refinancing of certain indebtedness owed to BBH and to repay indebtedness
owed to William Cone and Western Equities LLC. The Borrower shall within
thirty (30) days of the date hereof repay such indebtedness to William Cone
and Western Equities LLC and, as promptly as practicable thereafter (but in
no event more than fifteen (15) days thereafter), provide the Administrative
Agent with a copy of a written confirmation from each of William Cone and
Western Equities LLC that the indebtedness owed to each of them by the
Borrower has been paid in full.

                                      9
<PAGE>

5.21   INTELLECTUAL PROPERTY. Each Obligor has obtained and holds all
patents, trademarks, service marks, trade names and copyrights necessary to
conduct its business as presently conducted, and each thereof is in full
force and effect and no event has occurred which constitutes or, after notice
or lapse of time or both, would constitute, a material default under any
thereof. All patents, trademarks and copyrights owned by each Obligor (and
all pending applications of each Obligor for registration of patents,
trademarks and copyrights) as of the date hereof are listed in SCHEDULE 5.21
attached hereto.


                            6. AFFIRMATIVE COVENANTS

6.1    PAYMENTS. Each Obligor will duly and punctually pay all interest and
principal becoming due the Lenders and will duly and punctually perform all
things on its part to be done or performed under this Agreement.

6.2    BOOKS AND RECORDS; INSPECTION. Each Obligor will at all times keep
proper books of account in which full, true and correct entries will be made
of its transactions in accordance with generally accepted accounting
principles, consistently applied and which are, in the opinion of a certified
public accountant reasonably acceptable to the Administrative Agent, adequate
to determine fairly the financial condition and the results of operations of
each Obligor. Each Obligor will at all reasonable times make its books and
records available in its offices for inspection and examination by the
Administrative Agent and each Lender and the Administrative Agent's and each
Lender's representatives and, with at least one (1) business day's advance
notice, will permit inspection of the Collateral and all of its properties by
the Administrative Agent and each Lender and the Administrative Agent's and
each Lender's representatives during normal business hours so long as there
is no existing uncured Event of Default (as hereinafter defined) under this
Agreement or at any time (with or without notice at the Administrative
Agent's or such Lender's option, as applicable) if there is an existing
uncured Event of Default (as hereinafter defined). Each Obligor will from
time to time furnish the Administrative Agent and the Lenders with such
information and statements as the Administrative Agent and Lenders may
reasonably request with respect to the Obligations or the Administrative
Agent's and Lenders' security interest in the Collateral. Each Obligor shall,
during the term of this Agreement, keep the Administrative Agent currently
and accurately informed in writing of each location where each Obligor's
records relating to its accounts and contract rights are kept, and shall not
remove such records to another location without giving the Administrative
Agent at least thirty (30) days prior written notice thereof.

6.3    FINANCIAL STATEMENTS. The Obligors will furnish to the Administrative
Agent and the Lenders:

       (a)     as soon as available to the Obligors, but in any event within
               forty-five (45) days after the close of each quarterly period of
               their fiscal year, a full and complete signed copy of financial
               statements, which shall include a balance sheet of the Obligors,
               as at the end of such quarter, and statement of profit and loss
               of the Obligors reflecting the results of their operations during
               such quarter on a consolidated and consolidating basis, and shall
               be prepared by the Obligors and certified by the Chief Financial
               Officer of each Obligor as to correctness in accordance with
               generally accepted accounting principles, consistently applied;

       (b)     as soon as available to the Obligors, but in any event within
               ninety (90) days after the close of their fiscal year, a full and
               complete signed copy of financial statements, prepared by
               certified public accountants reasonably acceptable to the
               Lenders, which shall include a balance sheet of the Obligors, as
               at the end of such year, and statement of profit and loss of the
               Obligors reflecting the results of their operations during such
               year on a consolidated and consolidating basis, bearing the
               opinion of such certified public accountants and prepared on an
               audited basis in accordance with generally accepted accounting
               principles, consistently applied together with any so-called
               management letter;

       (c)     within thirty (30) days after the close of each fiscal year,
               financial projections and cash flow reports for the Obligors
               including projected borrowing through the then current fiscal
               year;

       (d)     within forty-five (45) days after end of each fiscal quarter, a
               Covenant Compliance Certificate in the form of EXHIBIT C attached
               hereto;

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<PAGE>

       (e)     from time to time, such financial data and information about any
               Obligor as the Administrative Agent or Lenders may reasonably
               request; and

       (f)     any financial data and information about any guarantors of the
               Obligations as the Administrative Agent or Lenders may reasonably
               request.

6.4    CONDUCT OF BUSINESS. Each Obligor will maintain its corporate
existence in good standing and comply with all laws and regulations of the
United States and of any state or states thereof and of any political
subdivision thereof, and of any governmental authority which may be
applicable to it or to its business; provided that this covenant shall not
apply to any tax, assessment or charge which is being contested in good faith
and with respect to which reserves have been established and are being
maintained.

6.5    NOTICE TO ACCOUNT DEBTORS. Each Obligor agrees, at the request of the
Administrative Agent, to notify all or any of the Debtors in writing of the
Administrative Agent's and Lenders' security interest in the Collateral in
whatever reasonable manner the Administrative Agent requests and, if the
Administrative Agent so requests, to permit the Administrative Agent to
notify all or any of the Debtors at such Obligor's expense.

6.6    OPERATING AND DEPOSIT ACCOUNTS. The Obligors shall maintain with BBH
their primary operating and deposit accounts which shall at all times have a
minimum balance of at least $150,000. At the option of the Lenders, all loan
payments and fees will automatically be debited from the Borrower's primary
operating accounts and all advances will automatically be credited to the
Borrower's primary operating accounts.

6.7    TAXES. Each Obligor will promptly pay all real and personal property
taxes, assessments and charges and all franchise, income, unemployment old
age benefits, withholding, sales and other taxes assessed against it or
payable by it before delinquent; provided that this covenant shall not apply
to any tax assessment or charge which is being contested in good faith and
with respect to which reserves have been established and are being
maintained. The Administrative Agent may, at its option, from time to time,
discharge any taxes, liens or encumbrances of any of the Collateral, and each
Obligor will pay to the Administrative Agent on demand or the Administrative
Agent in its sole discretion may charge to the Obligors all amounts so paid
or incurred by it.

6.8    MAINTENANCE. Each Obligor will keep and maintain the Collateral and
its other properties, if any, in good repair, working order and condition.
Each Obligor will promptly notify the Administrative Agent and the Lenders of
any loss or damage to or any occurrence which would materially adversely
affect the value of any Collateral. The Administrative Agent may, at its
option, from time to time, take any other action that the Administrative
Agent may deem proper to repair, maintain or preserve any of the Collateral,
and each Obligor will pay to the Administrative Agent on demand or the
Administrative Agent in its sole discretion may charge to the Obligors all
amounts so paid or incurred by it.

6.9    INSURANCE. Each Obligor will maintain in force casualty insurance on
all Collateral and any other property of such Obligor, if any, against risks
customarily insured against by companies engaged in businesses similar to
that of such Obligor containing such terms and written by such companies as
may be reasonably satisfactory to the Administrative Agent, such insurance to
be payable to the Administrative Agent for the ratable benefit of the
Administrative Agent and the Lenders as its interest may appear in the event
of loss; no loss shall be adjusted thereunder without the Administrative
Agent's approval; and all such policies shall provide that they may not be
canceled without first giving at least ten (10) days prior written notice of
cancellation to the Administrative Agent. In the event that any Obligor fails
to provide evidence of such insurance, the Administrative Agent may, at its
option, secure such insurance and charge the cost thereof to the Obligors. At
the option of the Administrative Agent, all insurance proceeds received from
any loss or damage to any of the Collateral shall be applied either to the
replacement or repair thereof or as a payment on account of the Obligations.
From and after the occurrence of an Event of Default (as hereinafter
defined), the Administrative Agent is authorized to cancel any insurance
maintained hereunder and apply any returned or unearned premiums, all of
which are hereby assigned to the Administrative Agent, as a payment on
account of the Obligations.

6.10   NOTIFICATION OF DEFAULT. Within five (5) days of becoming aware of the
existence of any condition or event which constitutes an Event of Default, or
any condition or event which would upon notice or lapse of time, or both,
constitute an Event of Default, the Obligors shall give the Administrative
Agent and the Lenders written notice thereof specifying the nature and
duration thereof and the action being or proposed to be taken with respect
thereto.

                                      11
<PAGE>

6.11   NOTIFICATION OF MATERIAL LITIGATION. Each Obligor will promptly notify
the Administrative Agent and the Lenders in writing of any litigation or of
any investigative proceedings of a governmental agency or authority commenced
or threatened against it which would or might be materially adverse to the
financial condition of such Obligor.

6.12   YEAR 2000. Each Obligor will take commercially reasonable actions to
ensure that such Obligor's computer systems and computer software shall at
all times contain no material deficiencies relating to the Year 2000 Problem;
and each Obligor hereby indemnifies and holds the Administrative Agent and
the Lenders harmless from any losses the Administrative Agent or the Lenders
may suffer resulting from any deficiencies in such Obligor's computer systems
or computer software relating to the Year 2000 Problem.

6.13   PENSION PLANS. With respect to any pension or benefit plan maintained
by any Obligor, or to which any Obligor contributes ("Plan"), the benefits
under which are guarantied, in whole or in part, by the Pension Benefit
Guaranty Corporation created by the Employee Retirement Income Security Act
of 1974, P.L. 93-406, or any governmental authority succeeding to any or all
of the functions of the Pension Benefit Guaranty Corporation ("Pension
Benefit Guaranty Corporation"), each Obligor will (a) fund each Plan as
required by the provisions of Section 412 of the Internal Revenue Code of
1986, as amended; (b) cause each Plan to pay all benefits when due; (c)
furnish the Administrative Agent (i) promptly with a copy of any notice of
each Plan's termination sent to the Pension Benefit Guaranty Corporation and
(ii) no later than the date of submission to the Department of Labor or to
the Internal Revenue Service, as the case may be, a copy of any request for
waiver from the funding standards or extension of the amortization periods
required by Section 412 of the Internal Revenue Code of 1986, as amended; and
(d) subscribe to any contingent liability insurance provided by the Pension
Benefit Guaranty Corporation to protect against employer liability upon
termination of a guarantied pension plan, if available to such Obligor.

6.14   ENVIRONMENTAL. As of the date hereof neither the Obligors nor any of
Obligors' agents, employees or independent contractors (1) have caused or are
aware of a release or threat of release of Materials (as hereinafter defined)
on any of the premises or personal property owned or controlled by any
Obligor, or any abutting property, which could give rise to any material
liability under any Superfund and Hazardous Waste Laws (as hereinafter
defined) or any other federal, state or local law, rule or regulation
relating to the protection of the environment or human safety; (2) have
arranged for the transport of or transported any Materials in a manner as to
violate, or result in potential liabilities under, any Superfund and
Hazardous Waste Laws; (3) have received any notice, order or demand from the
Environmental Protection Agency or any state or local agency or authority
under any Superfund and Hazardous Waste Laws; (4) have incurred any liability
under any Superfund and Hazardous Waste Laws in connection with the
mismanagement, improper disposal or release of Materials; (5) are aware of
any inspection or investigation of any of the premises or personal property
owned or controlled by any Obligor or abutting property by any federal, state
or local agency for possible violations of the Superfund and Hazardous Waste
Laws.

       To the best of each Obligor's knowledge, no prior owner or tenant of
any premises or property presently controlled or owned by such Obligor
committed or omitted any act which caused the release of Materials on such
premises or property which could give rise to a lien thereon by any federal,
state or local government. No notice or statement of claim or lien affecting
any property or premises owned or controlled by each Obligor has been
recorded or filed in any public records by any federal, state or local
government for costs, penalties, fines or other charges as to such property.

       Each Obligor agrees to indemnify and hold the Administrative Agent and
each Lender harmless from all liability, loss, cost, damage and expense,
including attorney fees and costs of litigation, arising from any and all of
its violations of the Superfund and Hazardous Waste Laws including those
arising from any lien on any premises or property owned or controlled by such
Obligor by any federal, state and local government arising from the presence
of Materials. Each Obligor further agrees to reimburse the Administrative
Agent and each Lender upon demand for any reasonable costs incurred by the
Administrative Agent and each Lender in connection with the foregoing. Each
Obligor agrees its obligations hereunder shall be continuous and shall
survive the repayment of all debts to Lenders and the Administrative Agent
including repayment of all Obligations.

       The term "Materials" means any "oil, "hazardous material," "hazardous
wastes" or "hazardous substances" as defined under the Comprehensive
Environmental Response, Compensation, and Liability Act. 42

                                      12
<PAGE>

U.S.C. Section 9601 ET SEQ., as amended, the Resource Conservation and
Recovery Act of 1976, 42 U.S.C. Section 6901 ET SEQ., as amended, any
applicable state or local statutes or ordinances, and regulations adopted
thereunder, and the foregoing are collectively the "Superfund and Hazardous
Waste Laws."

6.15   RATIFICATION OF LOAN DOCUMENTS. Within thirty (30) days after the date
hereof, the Borrower's Board of Directors, whether at a meeting of the Board
of Directors or by unanimous written consent, shall ratify and approve each
of the Loan Documents in its final form and shall promptly forward to the
Administrative Agent a copy of the unanimous written consent or minutes of
the meeting evidencing such ratification and approval.


                               7. NEGATIVE COVENANTS

7.1    FINANCIAL COVENANTS. The Obligors will not as of the last date of each
fiscal quarter beginning with the fiscal quarter ending February 28, 1999
fail to be in compliance with any of the financial covenants in this section
on a consolidated basis.

       (a)     DEFINITIONS. The following definitions shall apply to this
               Section:

               (i)    "Current Maturities of Long-Term Debt" shall mean all
               principal and lease payments to be paid by the Obligors during
               any fiscal period of Obligors on account of (A) the Revolving
               Loan, (B) the Term Loan; (C) other money borrowed from all
               sources and (D) capitalized leases.

               (ii)   "Tangible Net Worth" shall mean Obligors' stockholders'
               equity determined in accordance with generally accepted
               accounting principles, consistently applied, SUBTRACTING
               THEREFROM (A) intangibles (as determined in accordance with such
               principles so applied); and (B) Accounts Receivable and
               Indebtedness owing to an Obligor from any employee, stockholder
               or parent, subsidiary or other affiliate of such Obligor,

               (iii)  "Indebtedness" shall mean, with respect to any person (A)
               all indebtedness for borrowed money or for the deferred purchase
               price of property or services, and all obligations under leases
               which are or should be under generally accepted accounting
               principles recorded as capital leases, in respect of which such
               person is directly or contingently liable as borrower, guarantor,
               endorser or otherwise, or in respect of which such person
               otherwise assures a creditor against loss, (B) all indebtedness
               for borrowed money or for the deferred purchase price of property
               or services secured by (or for which the holder has an existing
               right, contingent or otherwise, to be secured by) any lien upon
               property (including without limitation accounts receivable and
               contract rights) owned by such person, whether or not such person
               has assumed or become liable for the payment thereof, and (C) all
               other liabilities or obligations which would, in accordance with
               generally accepted accounting principles, be classified as
               liabilities of such person.

               (iv)   "Subordinated Indebtedness" shall mean Indebtedness which
               is expressly subordinated to Senior Indebtedness (as hereinafter
               defined) in writing pursuant to subordination agreements
               acceptable to the Lenders.

               (v)    "Senior Indebtedness" shall mean any amount of any
               Indebtedness owing by the Borrower to the Lenders.

               (vi)   "Current Assets" and "Current Liabilities" shall be
               defined according to generally accepted accounting principles.

               (vii)  "Income" and "Net Income" shall be defined according to
               generally accepted accounting principles.

       (b)     TANGIBLE CAPITAL BASE. The Obligors will not permit their
               Tangible Net Worth plus their Subordinated Indebtedness
               ("Tangible Capital Base") as of the last date of each fiscal
               quarter beginning with the fiscal quarter ending February 28,
               1999 to be less than $7,450,000 plus seventy-five percent (75%)
               of the Obligors' Net Income for each fiscal quarter beginning
               with the fiscal quarter ending November 30, 1998 plus the amount
               of amortization of Obligors' intangibles for each fiscal quarter
               beginning with the fiscal quarter ending November 30, 1998 plus
               the amount of any new equity raised by Obligors Such

                                      13
<PAGE>

               minimum requisite Tangible Capital Base amount shall not be
               reduced by any net losses of the Obligors.

       (c)     SENIOR INDEBTEDNESS TO EBITDA. For all periods beginning with the
               fiscal quarter ending February 28, 1999, the Obligors will not as
               of the last date of each fiscal quarter permit the aggregate
               amount of their Senior Indebtedness to be more than two (2) times
               the sum of their EBITDA for the Obligors' trailing four (4)
               fiscal quarters. "EBITDA" shall mean earnings before interest,
               tax, depreciation and amortization expense as defined according
               to generally accepted accounting principles, consistently
               applied.

       (d)     CURRENT RATIO. The Obligors will not as of the last date of each
               fiscal quarter beginning with the fiscal quarter ending February
               28, 1999 permit the ratio of their Current Assets to Current
               Liabilities, excluding any Current Maturities of Long-Term Debt,
               to be less than 1.4:1.0.

       (e)     COVERAGE RATIO. The Obligors will not as of the last date of each
               fiscal quarter beginning with the fiscal quarter ending February
               28, 1999 permit the amount of their EBITDA for the trailing four
               (4) fiscal quarters of the Obligors plus payments under all
               leases minus any cash dividends and distributions minus capital
               expenditures minus taxes paid by the Obligors to be less than 1.4
               times the sum of all interest expense plus all principal payments
               (to all creditors) plus payments under all leases, all for the
               trailing four (4) fiscal quarters of the Obligors.

7.2    LIMITATIONS ON INDEBTEDNESS. Each Obligor will not issue any evidence
of indebtedness or create, assume, guarantee, become contingently liable for,
or suffer to exist indebtedness in addition to Indebtedness to the Lenders,
except (i) Indebtedness or liabilities of such Obligor for money borrowed,
incurred or arising in the ordinary course of business within the limits
provided for in this Agreement, (ii) Indebtedness relating to the Borrower's
12% Senior Subordinated Debentures due 2005 (including all guarantees
thereof), (iii) Indebtedness of any Obligor which is subordinated to the
Senior Indebtedness on terms and conditions acceptable to the Lenders, (iv)
Indebtedness secured by liens permitted pursuant to Section 7.10 hereof, or
(v) Indebtedness which is incurred after the date hereof, is non-recourse to
the Obligors, is incurred in connection with the acquisition of (A) assets of
another Person by any Obligor or (B) stock by any Obligor, and is secured
solely by the stock or assets so acquired.

7.3    SALE OF INTEREST. There shall not be any sale or transfer of ownership
of any interest in any subsidiary of the Borrower which is an Obligor
hereunder without the Lenders' prior written consent.

7.4    LOANS OR ADVANCES. Each Obligor will not make any loans or advances to
any individual, firm or corporation, including, without limitation, its
officers and employees; provided, however, that (i) an Obligor may make
advances to its employees, including its officers, with respect to expenses
incurred or to be incurred by such employees which expenses are reimbursable
by such Obligor; (ii) each Obligor may extend credit in the ordinary course
of business in accordance with customary trade practices; (iii) each Obligor
may own, purchase or acquire Permitted Investments, or otherwise make an
investment in a Person not otherwise permitted pursuant to this Section,
provided the amount of such investment for all Obligors collectively shall
not exceed $25,000 per individual investment or $50,000 in the aggregate; and
(iv) each Obligor may make or permit to remain outstanding loans or advances
to any other Obligor named herein.

7.5    DIVIDENDS AND DISTRIBUTIONS. Each Obligor may, without prior written
permission of the Administrative Agent or the Lenders, pay any dividends on
or make any distribution on account of any class of such Obligor's capital
stock in cash or in property (other than additional shares of such stock), or
redeem, purchase or otherwise acquire, directly or indirectly, any of such
stock, provided that no such payments or distribution shall cause any
Obligor, after effecting any such dividend or distribution, to fail to comply
with any other provisions of this Agreement, including, without limitation,
each of the financial covenants set forth in Section 7.1 of this Agreement.

7.6    INTENTIONALLY OMITTED.

7.7    INVESTMENTS. Each Obligor will not make investments in, or advances
to, any individual, partnership, corporation, limited liability company,
trust or other organization or person, nor purchase or otherwise invest in or
hold securities, nonoperating real estate or other nonoperating assets or
purchase all or substantially all the assets of any entity; except the
Obligors or any Obligor may

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<PAGE>

       (a)     own, purchase or acquire Permitted Investments;

       (b)     endorse negotiable instruments for collection in the ordinary
               course of business;

       (c)     make an investment in a Person not otherwise permitted pursuant
               to this Section 7.7, provided the amount of such investment
               (including the amount of any guarantee, endorsement or other
               liability with respect thereto) for all Obligors collectively
               shall not exceed $25,000 per individual investment or $50,000 in
               the aggregate;

       (d)     make an investment in a Person that becomes a wholly-owned
               subsidiary as a result of such investment or in assets of a
               Person that become assets of an Obligor provided that: (i) such
               investments relate to the acquisition of companies engaged in the
               business of whole blood or plasma collection, processing and
               marketing, selling of blood and blood byproducts and any related
               business or activities; (ii) the Obligors shall deliver to the
               Administrative Agent pro forma financial statements reflecting
               the investment and related calculations demonstrating compliance
               with all covenants contained herein relating to financial and
               accounting matters, together with a description in reasonable
               detail of the nature and reasons for the proposed transaction,
               provided, however, that such pro forma financial statements shall
               contain an appropriate footnote describing the nature and source
               of any known contingent liabilities in connection with such
               investment; (iii) immediately after giving effect to such
               transaction, no Event of Default shall exist and be continuing;
               (iv) such investments do not exceed $5,000,000 in cash purchase
               price for the Obligors in any one fiscal year; and (v) with
               respect to any investment that contemplates the assumption by any
               Obligor of any contingent liabilities either by agreement or by
               merger with or into the entity that is subject to such contingent
               liabilities, the Administrative Agent shall approve such
               investment prior to the consummation of such investment (which
               approval shall not be unreasonably withheld, conditioned or
               delayed); and

       (e)     make or permit to remain outstanding loans or advances to any
               wholly owned subsidiary (hereafter created).

       By way of example and not limitation, the acquisition by any Obligor
of the capital stock of any entity that has contingent liabilities shall not
be subject to the prior approval of the Administrative Agent pursuant to
clause (v) of Section 7.7(d) above so long as the applicable acquisition
agreement does not contemplate that such acquired entity be merged with or
into any Obligor or that any Obligor otherwise become directly liable for the
contingent liabilities of such entity.

7.8    MERGER. Each Obligor will not merge or consolidate or be merged or
consolidated with or into any other corporation except that any Obligor may
enter into a merger in connection with an investment permitted by Section
7.7, and except that any Obligor may be merged, consolidated, dissolved or
liquidated into any other Obligor.

7.9    SALE OF ASSETS. Except for the planned dispositions of certain real
property located in South Bend, Indiana, Kalamazoo, Michigan, Salt Lake City,
Utah and Fort Worth, Texas, each Obligor will not sell, lease or otherwise
dispose of any of its assets except (i) in the ordinary and usual course of
business and except for the purpose of replacing machinery, equipment or
other personal property which, as a consequence of wear, duplication or
obsolescence, is no longer used or necessary in such Obligor's business,
provided that fair consideration is received therefor; (ii) if the net
proceeds of such sale are applied to the repayment of the Senior
Indebtedness; (iii) if the net proceeds of such sale are reinvested in the
business of the Obligors or are otherwise invested pursuant to Section 7.7
hereof; or (iv) if in the aggregate all of the transfers made by all Obligors
since the date hereof and not otherwise permitted by clause (i), (ii) or
(iii) above amounts to less than $200,000. Notwithstanding this Section 7.9,
no assets of any Obligor shall be sold, disposed of or otherwise conveyed (i)
at less than fair market value or (ii) if any Event of Default (as
hereinafter defined) shall have occurred and then be continuing or shall
result from such sale or disposition.

7.10   RESTRICTION ON LIENS. Each Obligor will not grant any security
interest in, or mortgage of, any of its properties or assets including the
Collateral except (i) liens for taxes not yet due or which are being
contested in good faith by appropriate proceedings and for which adequate
reserves have been established in accordance with generally accepted
accounting principles ("GAAP"); (ii) statutory liens of landlords and liens
of carriers, warehousemen, mechanics, materialmen and other similar Persons
and other liens imposed by law incurred in the ordinary course of business
for sums not yet delinquent or being contested in good faith, if such
reserves or other

                                      15
<PAGE>

appropriate provision, if any, as shall be required by GAAP shall have been
made therefor; (iii) liens made to secure Senior Indebtedness; (iv) liens
incurred through purchase money security interests or in connection with
equipment leases in amounts which, at the time incurred, do not exceed the
fair market value of the asset securing such lien and such lien extends only
to the asset leased or financed; provided that any indebtedness or leases
incurred in any year secured by such liens shall not exceed $1,000,000 in the
aggregate for all Obligors; (v) liens securing Indebtedness permitted under
Section 7.2 hereof; and (vi) liens or deposits made to secure payment of
workers' compensation, or in connection with the participation in any fund in
connection with workers' compensation, unemployment insurance, pensions or
other social security programs.

7.11   OTHER BUSINESS. Each Obligor will not engage in any business other
than the business in which it is currently engaged or a business reasonably
allied thereto.

                                  8. DEFAULT

8.1    DEFAULT. "Event of Default" shall mean the occurrence of one or more of
any of the following events:

       (a)     the Borrower or any other Obligor defaults in the payment of any
               principal of or interest on any Senior Indebtedness when the same
               shall become due, either by the terms thereof or otherwise as
               herein provided, and in the case of interest payments, such
               default shall continue for a period of three (3) business days
               after such date;

       (b)     the Borrower or any other Obligor defaults in the payment when
               due, either by the terms thereof or otherwise as herein provided,
               of any other amounts on any Senior Indebtedness and such default
               shall continue unremedied for five (5) or more business days;

       (c)     the Borrower or any other Obligor (i) defaults in any payment of
               principal of or interest on any other Indebtedness in an amount
               exceeding $100,000 and such default shall continue beyond any
               applicable grace period or (ii) fails to perform or observe any
               other agreement, term or condition contained in any agreement
               under which any such obligation is created (or if any other event
               thereunder or under any such agreement shall occur and be
               continuing), and in the case of (ii) above, the effect of such
               default, failure or other event is to cause, or, with respect to
               any Indebtedness, to permit the holder or holders of such
               obligation (or a trustee on behalf of such holder or holders) to
               cause an obligation of more than $100,000 to become due prior to
               any stated maturity;

       (d)     the Borrower or any other Obligor defaults in the performance or
               observance of any of the agreements (other than payment defaults
               and defaults which are unable to be cured) contained in Section 6
               (Affirmative Covenants) or Section 7 (Negative Covenants) hereof
               or in the performance or observance of any other material
               agreement, term or condition contained herein or in the other
               Loan Documents and any such default shall not have been remedied
               within thirty (30) days after the first date such default in the
               exercise of commercially reasonable diligence should have become
               known to any officer of any Obligor, provided, however, that such
               thirty (30) day cure period shall not apply to a default under
               Section 6.15 of this Agreement;

       (e)     If any statement, representation or warranty heretofore, now or
               hereafter made in connection with this Agreement or in any
               supporting financial statement of any Obligor shall be determined
               by the Administrative Agent or a Lender to have been false in any
               material respect when made, and if susceptible to cure. such
               inaccuracy shall not have been remedied within thirty (30) days
               after the first date such default in the exercise of commercially
               reasonable diligence should have become known to any officer of
               any Obligor;

       (f)     The liquidation, termination or dissolution of, or the merger or
               consolidation of, any Obligor, with or into another entity
               (except as otherwise permitted hereunder without the consent of
               the Lenders), or any Obligor ceasing to carry on actively its
               present business or the appointment of a receiver

                                      16
<PAGE>

               for any Obligor.

       (g)     The institution by or against any Obligor or guarantor of the
               Obligations of any proceedings under the Bankruptcy Code 11 USC
               Section 101 ET SEQ. or any other law in which any Obligor or any
               guarantor of the Obligations is alleged to be insolvent or
               unable to pay their respective debts as they mature, or the
               making by any Obligor or any guarantor of the Obligations of an
               assignment for the benefit of creditors or the granting of a
               trust mortgage for the benefit of creditors.

       (h)     The service upon the Administrative Agent or a Lender hereof of a
               writ in which the Administrative Agent or a Lender is named as
               trustee of any Obligor or of any guarantor of the Obligations.

       (i)     A judgment or judgments for the payment of money in excess of
               $100,000 over and above the amount of such judgment actually paid
               by insurance shall be rendered against any Obligor and any such
               judgment shall remain unsatisfied and in effect for any period of
               sixty (60) consecutive days without a stay of execution.

       (j)     Any levy, seizure, attachment, execution or similar process shall
               be issued or levied on any of the property of any Obligor having
               a material adverse affect on any Obligor.

       (k)     The termination of any guaranty of the Obligations.

       (l)     The occurrence of such a materially adverse change in the
               condition or affairs (financial or otherwise) of any Obligor
               such that the prospects for timely or full payment or
               performance of any of the Obligations have been or are
               reasonably likely to be substantially impaired.

8.2    DEFAULT REMEDIES. If an Event of Default shall occur, at the election
of the Lenders, all Obligations shall become immediately due and payable upon
written notice or demand (except that no written notice or demand shall be
required in the case of an Event of Default under Sections 8.1(e) or 8.1(g)
above).

       The Administrative Agent is hereby authorized, at its election and at
the direction of the Lenders, after an Event of Default, without any further
demand or notice except to such extent as notice may be required by
applicable law, to take possession and/or sell or otherwise dispose of all or
any of the Collateral at public or private sale; and the Administrative Agent
and Lenders may also exercise any and all other rights and remedies of a
secured party under the Code or which are otherwise accorded to them by
applicable law, all as the Lenders may determine. If notice of a sale or
other action by the Administrative Agent is required by applicable law,
unless the Collateral is perishable or threatens to decline speedily in value
or is of a type customarily sold on a recognized market, each Obligor agrees
that five (5) days' written notice to such Obligor, or the shortest period of
written notice permitted by such law, whichever is larger, shall be
sufficient notice; and that to the extent permitted by law, the
Administrative Agent and the Lenders, their officers, attorneys and agents
may bid and become purchasers at any such sale, if public, and may purchase
at any private sale any of the Collateral that is of a type customarily sold
on a recognized market or which is the subject of widely distributed standard
price quotations. Any sale (public or private) shall be free from any right
of redemption, which each Obligor hereby waives and releases. No purchaser at
any sale (public or private) shall be responsible for the application of the
purchase money. Any balance of the net proceeds of sale remaining after
paying all Obligations of the Obligors to the Lenders and the Administrative
Agent shall be returned to the Obligors or to such other party as may be
legally entitled thereto; and if there is a deficiency, the Obligors shall be
responsible for the same, with interest, to the extent permitted by
applicable law. Upon demand by the Administrative Agent, each Obligor shall
assemble the Collateral and make it available to the Administrative Agent at
a place designated by the Administrative Agent which is reasonably convenient
to the Administrative Agent and such Obligor. Each Obligor hereby
acknowledges that the Lenders have extended credit and other financial
accommodations to the Obligors upon reliance of such Obligor's granting the
Administrative Agent and the Lenders the rights and remedies contained in
this Agreement including, without limitation, the right to take immediate
possession of the Collateral upon the occurrence of an Event of Default and
each Obligor hereby acknowledges that the Administrative Agent and the
Lenders are entitled to equitable and injunctive relief to enforce any of
their rights and remedies hereunder or under the Code and each Obligor hereby
waives any defense to such equitable or injunctive relief based upon any
allegation of the absence of irreparable

                                      17
<PAGE>

harm to the Administrative Agent or Lenders.

8.3    POWER OF ATTORNEY. Each Obligor hereby irrevocably constitutes and
appoints the Administrative Agent as such Obligor's true and lawful attorney,
with full power of substitution, at the sole cost and expense of such Obligor
but for the sole benefit of the Administrative Agent and the Lenders, upon
the occurrence of an Event of Default to convert the Collateral into cash,
including, without limitation, completing the manufacture or processing of
work in process, and the sale (either public or private) of all or any
portion or portions of the Inventory and other Collateral; to enforce
collection of the Collateral, either in its own name or in the name of such
Obligor, including, without limitation, executing releases, compromising or
settling with any Debtors and prosecuting, defending, compromising or
releasing any action relating to the Collateral; to receive, open and dispose
of all mail addressed to any Obligor and to take therefrom any remittances or
proceeds of Collateral in which the Administrative Agent and the Lenders have
a security interest; to notify U.S. Postal Service authorities to change the
address for delivery of mail addressed to any Obligor to such address as the
Administrative Agent shall designate; to open and administer a lock-box in
which Lenders may direct any Obligor to deposit or have deposited any
payments owed to such Obligor, to endorse the name of any Obligor in favor of
the Administrative Agent upon any and all checks, drafts, money orders,
notes, acceptances or other instruments of the same or different nature; to
sign and endorse the name of any Obligor on and to receive as secured party
any of the Collateral, any invoices, schedules of Collateral, freight or
express receipts, or bills of lading, storage receipts, warehouse receipts,
or other documents of title of the same or different nature relating to the
Collateral; to sign the name of any Obligor on any notice to the Debtors or
on verification of the Collateral; and to sign and file or record on behalf
of any Obligor any financing or other statement in order to perfect or
protect the Administrative Agent's and Lenders' security interest. The
Administrative Agent shall not be obliged to do any of the acts or exercise
any of the powers hereinabove authorized, but if the Administrative Agent
elects to do any such act or exercise any such power, it shall not be
accountable for more than it actually receives as a result of such exercise
of power, and it shall not be responsible to any Obligor except for willful
misconduct in bad faith. All powers conferred upon the Administrative Agent
by this Agreement, being coupled with an interest, shall be irrevocable so
long as any Obligation of any Obligor to the Lenders or Administrative Agent
shall remain unpaid.

8.4    NONEXCLUSIVE REMEDIES. All of the Administrative Agent's and Lenders'
rights and remedies not only under the provisions of this Agreement but also
under any other agreement or transaction shall be cumulative and not
alternative or exclusive, and may be exercised by the Administrative Agent
and Lenders, as applicable, at such time or times and in such order of
preference as the Administrative Agent or the Lenders in their sole
discretion, as applicable, may determine.

8.5    REASSIGNMENT TO OBLIGORS. Whenever the Lenders deem it desirable that
any legal action be instituted with respect to any Collateral or that any
other action be taken in any attempt to effectuate collection of any
Collateral, the Administrative Agent may reassign the item in question to the
respective Obligor (and if the Administrative Agent shall execute any such
reassignment, it shall automatically be deemed to be without recourse to the
Administrative Agent in any event) and require such Obligor to proceed with
such legal or other action at such Obligor's sole liability, cost and
expense, in which event all amounts collected by such Obligor on such item
shall nevertheless be subject to the Administrative Agent's and Lenders'
security interest.


                            9. THE ADMINISTRATIVE AGENT

9.1    APPOINTMENT POWERS AND IMMUNITIES. Each Lender hereby irrevocably
appoints and authorizes the Administrative Agent to act as its agent
hereunder and under each of the Loan Documents with such powers as are
specifically delegated to the Administrative Agent by the terms of this
Agreement and the Loan Documents, together with such other powers as are
reasonably incidental thereto. The Administrative Agent (which term as used
in this sentence and in Section 9.7 and the first sentence of Section 9.8
shall include reference to its Affiliates (as hereinafter defined) and the
respective officers, directors, employees and agents of the Administrative
Agent and its Affiliates); (a) shall have no duties or responsibilities
except those expressly set forth in this Agreement to be a trustee for any
Lender (b) shall not be responsible to the Lenders for any recitals.
statements, representations or warranties of any Obligor contained in this
Agreement, or in any certificate or other document referred to or provided
for in, or received by any of them under, this Agreement, or for the value,
validity, effectiveness, genuineness, enforceability, perfection or
sufficiency of this Agreement any promissory note or any other

                                      18
<PAGE>

document referred to or provided for herein or for any failure by any Obligor
or any other Person to perform any of its obligations hereunder or
thereunder; (c) shall not be empowered or required to initiate or conduct any
litigation or collection proceedings hereunder except to the extent requested
by or consented to by the Lenders; (d) shall not be empowered or required to
alter or amend any term of this Agreement or the Loan Documents except to the
extent requested by or consented to in writing by the Lenders; (e) except to
the extent requested by or consented to in writing by the Lenders, shall not
be empowered or required to foreclose on the Collateral or enter into any
forbearance arrangement with any Obligor or enter into any arrangement with
any Obligor for the restructuring of the Revolving Loan or Term Loan; and (f)
shall not be responsible for any action taken or omitted to be taken by it
hereunder or under any other document or instrument referred to or provided
for herein or in connection herewith, except for its own gross negligence or
willful misconduct, "Affiliates" shall mean with respect to any Person (i)
each Person that, directly or indirectly, owns or controls, whether
beneficially, or as a trustee, guardian or other fiduciary 5% or more of the
securities or interests having ordinary voting power in the election of
directors of such Person, (ii) each Person that controls, is controlled by or
is under common control with such Person or any Affiliate of such Person and
(iii) each of such Person's officers, directors, joint venturers and partners
(for the purpose of this definition, "control" of a Person shall mean the
possession, directly or indirectly, of the power to direct or cause the
direction of its management or policies, whether through the ownership of
voting securities, by contract or otherwise). The Administrative Agent may
employ agents and attorneys-in-fact and shall not be responsible for the
negligence or misconduct of any such agents or attorneys-in-fact selected by
it with reasonable care. Subject to the foregoing, the Administrative Agent
shall, on behalf of the Lenders, exercise any and all rights, powers and
remedies of the Lenders under this Agreement and any other Loan Documents,
including the giving of any consent or waiver or the entering into of any
amendment, subject to the provisions of Section 10.9 below.

9.2    REVOLVING LOAN ADVANCES. Upon receipt by the Administrative Agent of a
request from the Borrower for an advance under the Revolving Loan specifying
the amount and date of such advance, the Administrative Agent shall promptly
notify the Lenders by telephone or facsimile transmission of such request.
Each Lender, before 1:00 pm (Boston, Massachusetts time) on the specified
date of such advance, shall make available to the Administrative Agent in
immediately available funds by wire transfer at its office at 40 Water
Street, Boston, Massachusetts 02109, such Lender's pro-rata share of such
advance. If a Lender shall fail to provide the Administrative Agent with its
pro-rata share of a requested advance as provided for in this Section, the
Administrative Agent, in its sole discretion and upon notice to such Lender,
may refuse to make available to the Borrower such Lender's pro-rata share of
such advance.

9.3    DISTRIBUTION OF PAYMENTS BETWEEN LENDERS AND ADMINISTRATIVE AGENT.

       (a)     All payments and prepayments of principal of and interest on the
               Loans received by the Administrative Agent shall be paid to each
               of the Lenders pro rata in accordance with their respective
               pro-rata shares in such Loans in immediately available funds by
               wire transfer no later than 1:00 p.m. (Boston, Massachusetts
               time) on the Business Day immediately following the date on which
               such payments or prepayments are received by the Administrative
               Agent, and any other payments received by the Administrative
               Agent hereunder shall be paid in the same manner to the Lenders
               or the Administrative Agent or both pro rata as their respective
               interests appear. No Obligor shall have any liability whatsoever
               to any Lender or the Administrative Agent for any errors made by
               the Administrative Agent in allocating between the Lenders any
               payment made by such Obligor to the Administrative Agent or for
               any conflicts regarding allocation or distribution of such
               payment between the Lenders.

       (b)     Each of the Lenders and the Administrative Agent hereby agrees
               that if it should receive any amount (whether by voluntary
               payment, by the exercise of the right of set-off or banker's
               lien, by counterclaim or cross action, by the enforcement of any
               right hereunder or otherwise) in respect of principal of, or
               interest on, the Loans, or any fees which are to be shared
               between the Lenders, which, as compared to the amounts
               theretofore received by the other Lender with respect to such
               principal, interest or fees, is in excess of such receiving
               Lender's pro-rata share of such principal, interest or fees as
               provided in this Agreement, such Lender shall share such excess,
               less the costs and expenses (including, reasonable attorneys'
               fees and disbursements) incurred by such Lender in connection
               with such realization, exercise, claim or action pro rata with
               the other

                                      19
<PAGE>

               Lender in proportion to their respective interests therein.

       (c)     In the event that a Lender has not made available to the
               Administrative Agent its pro-rata share of an advance or
               advances requested by the Borrower in accordance with the terms
               of this Agreement and the other Lender has made available its
               pro-rata share of such advance or advances, and the
               Administrative Agent has made available to the Borrower the
               other Lenders pro-rata share of such advance or advances, then
               the Administrative Agent shall pay all principal and interest
               payments and prepayments received by the Administrative Agent
               first to the other Lender which made available its pro-rata
               share of such advance or advances until the amount of such other
               Lender's pro-rata share made available to the Borrower has been
               repaid to such other Lender in full and the Lenders' respective
               pro-rata shares in outstanding advances made to the Borrower are
               equal to those pro-rata shares set forth in attached EXHIBIT A.
               No Obligor shall have any liability whatsoever to any Lender or
               the Administrative Agent who, pursuant to this Section 9.3(c),
               fails to receive any portion or all of any principal or interest
               payments or prepayments made by the Borrower to the
               Administrative Agent pursuant to this Agreement.

9.4    RELIANCE BY AGENT. The Administrative Agent shall be entitled to rely
upon any certifications, notices or communications (including any
communications by telephone, facsimile, telex, telegram or cable) believed by
it to be genuine and correct and to have been signed or sent by or on behalf
of the proper Person or Persons, and upon advice and statements of legal
counsel, independent accountants and other experts selected by the
Administrative Agent. As to any matters not expressly provided for by this
Agreement, the Administrative Agent shall in all cases be fully protected in
acting, or in refraining from acting, hereunder in accordance with the
instructions of the Lenders, and any action taken or failure to act pursuant
thereto shall be binding on the Lenders.

9.5    DEFAULTS. The Administrative Agent shall not be deemed to have
knowledge of the occurrence of an Event of Default (other than the nonpayment
of principal of or interest on the Revolving Note or Term Note (hereinafter
collectively referred to as the "Notes") unless the Administrative Agent has
received written notice from a Lender or the Borrower specifying such Event
of Default. In the event that the Administrative Agent receives such a notice
of the occurrence of an Event of Default, the Administrative Agent shall give
notice thereof to the Lenders (and shall give each Lender prompt notice of
each such nonpayment). The Administrative Agent shall (subject to the
provisions of Sections 9.9 and 10.15 below) take such action with respect to
such Event of Default as shall be directed by the Lenders, provided, that,
unless and until the Administrative Agent shall have received such
directions, the Administrative Agent may (but shall not be obligated to) take
such action, or refrain from taking such action, with respect to such Event
of Default as it shall deem advisable and in the best interests of the
Lenders.

9.6    RIGHTS AS A LENDER. With respect to its pro-rata share of the Loans
made by it, BBH, in its capacity as a Lender hereunder, shall have the same
rights and powers hereunder as the other Lender and may exercise the same as
though it were not acting as the Administrative Agent, and the term "Lender"
or "Lenders" shall, unless the context otherwise indicates, include the
Administrative Agent in its individual capacity. The Administrative Agent and
its Affiliates may (without having to account therefor to any Lender) accept
deposits from and generally engage in any kind of banking, trust or other
business with any Obligor or any of its Affiliates, as if the Administrative
Agent were not acting as the agent hereunder, and the Administrative Agent
may accept fees and other consideration from any of such Persons for services
as the Administrative Agent or otherwise without having to account for the
same to the Lenders.

9.7    INDEMNIFICATION. The Lenders agree to indemnify the Administrative
Agent ratably in accordance with the aggregate principal amount of the Notes
held by the Lenders (or, if no such principal is at the time outstanding,
ratably in accordance with their respective pro-rata shares set forth in
attached EXHIBIT A), for any and all liabilities, obligations, losses,
damages, penalties, actions, judgments, suits, costs, expenses or
disbursements of any kind and nature whatsoever which may be imposed on,
incurred by or asserted against the Administrative Agent in any way relating
to or arising out of this Agreement or the transactions contemplated hereby
or referred to herein or therein (including the costs and expenses which any
Obligor is obligated to pay but excluding, unless an Event of Default has
occurred and is continuing, normal administrative costs and expenses incident
to the performance of its agency duties hereunder) or the enforcement of any
of the terms of this Agreement or of any such other

                                      20
<PAGE>

documents, provided that no Lender shall be liable for any of the foregoing
to the extent they arise from the gross negligence or willful misconduct of
the Administrative Agent.

9.8    NON-RELIANCE ON ADMINISTRATIVE AGENT AND OTHER LENDER. Each Lender
agrees that it has, independently and without reliance on the Administrative
Agent or the other Lender, and based on such documents and information as it
has deemed appropriate, made its own credit analysis of the Obligors and its
own decision to enter into this Agreement and that it will, independently and
without reliance upon the Administrative Agent or the other Lender, and based
on such documents and information as it shall deem appropriate at the time,
continue to make its own analysis and decisions in taking or not taking
action under this Agreement. The Administrative Agent shall not be required
to keep itself informed as to the performance or observance by the Obligors
of this Agreement or any other document referred to or provided for herein or
to inspect the properties or books of the Obligors. Except for any notices,
reports and other documents and information expressly required to be
furnished to the Lenders by the Administrative Agent hereunder, the
Administrative Agent shall not have any duty or responsibility to provide any
Lender with any credit or other information concerning the affairs, financial
condition or business of the Obligors which may come into the possession of
the Administrative Agent or any of its Affiliates. Notwithstanding the
foregoing, the Administrative Agent will use its best efforts to provide to
the Lenders any and all information reasonably requested by them and
reasonably available to the Administrative Agent promptly upon such request.

9.9    FAILURE TO ACT. Except for action expressly required of the
Administrative Agent hereunder, the Administrative Agent shall in all cases
be fully justified in failing or refusing to act hereunder unless it shall be
indemnified to its satisfaction by the Lenders against any and all liability
and expense which may be incurred by it by reason of taking or continuing to
take any such action.

9.10   RESIGNATION OF ADMINISTRATIVE AGENT. Subject to the appointment and
acceptance of a successor Administrative Agent as provided below, the
Administrative Agent may resign at any time by giving notice thereof to the
Lenders and the Borrower. Upon any such resignation, the Lenders shall
appoint a successor Administrative Agent which shall be reasonably
satisfactory to the Borrower. If no successor Administrative Agent shall have
been so appointed by the Lenders and shall have accepted such appointment
within thirty (30) days after the retiring Administrative Agent's giving of
notice of resignation, then the retiring Administrative Agent may, on behalf
of the Lenders, appoint a successor Administrative Agent which shall be a
Lender which has a combined capital and surplus of at least $500,000,000 and
which shall be reasonably satisfactory to the Borrower. Upon the acceptance
of any appointment as Administrative Agent hereunder by a successor
Administrative Agent, such successor Administrative Agent shall thereupon
succeed to and become vested with all the rights, powers, privileges and
duties of the retiring Administrative Agent, and the retiring Administrative
Agent shall be discharged from its duties and obligations hereunder. After
the retiring Administrative Agent's resignation hereunder as Administrative
Agent, the provisions of this Section 9 shall continue in effect for its
benefit in respect of any actions taken or omitted to be taken by it while it
was acting as the Administrative Agent.

9.11   COOPERATION OF LENDERS. Each Lender shall (a) endeavor to and shall
not be liable for any failure to promptly notify the other Lender and the
Administrative Agent of any Events of Default known to such Lender under this
Agreement and not reasonably believed to have been previously disclosed to
the other Lender; and (b) provide the other Lender and the Administrative
Agent with such information and documentation as such other Lender or the
Administrative Agent shall reasonably request in the performance of their
respective duties hereunder, including all information relative to the
outstanding balance of principal, interest and other sums owed to such Lender.

9.12   AMENDMENT OF SECTION 9. Each Obligor hereby agrees that the provisions
of this Section 9 (other than Sections 9.10 and 9.13) generally constitute an
agreement among the Administrative Agent and the Lenders and that any and all
of the provisions of this Section 9 (other than Sections 9.10 and 9.13) may
be amended at any time by the Lenders and Administrative Agent without the
consent or approval of, or notice to, any Obligor (other than the requirement
of notice to the Borrower of the resignation of the Administrative Agent and
other than any provision in addition to Sections 9.10 and 9.13 which affects
the Obligors). Any required consent or approval of any Obligor with respect
to an amendment of Section 9.10 hereof shall not be unreasonably withheld or
delayed.

9.13   RELIANCE. As to any consent that is granted or any other action that
is taken by the Administrative Agent hereunder, or under the Loan Documents
the Obligors shall be entitled to rely any of the foregoing granted.

                                      21
<PAGE>

delivered or taken by the Administrative Agent, and the Lenders shall be
bound thereby, without the necessity of any Obligor inquiring or confirming
the Administrative Agent's authority.

9.14   MINIMUM PRO-RATA SHARE OF BBH. So long as BBH serves as Administrative
Agent hereunder, BBH shall at all times maintain a pro-rata share in the
Loans of at least 25%.


                                10. MISCELLANEOUS

10.1   WAIVERS. Each Obligor waives notice of nonpayment, demand,
presentment, protest or notice of protest of the Collateral, and all other
notices, consents to any renewals or extensions of time of payment thereof,
and generally waives any and all suretyship defenses and defenses in the
nature thereof.

10.2   SEVERABILITY. If any provision of this Agreement or portion of such
provision or the application thereof to any person or circumstance shall to
any extent be held invalid or unenforceable, the remainder of this Agreement
(or the remainder of such provision) and the application thereof to other
persons or circumstances shall not be affected thereby.

10.3   SET-OFF. Any deposits, balances or other sums credited by or due from
a Lender or any of its Affiliates to any Obligor and any security or other
property of any Obligor in the possession of such Lender, whether for
safekeeping or otherwise, may, at any time whether or not an Event of Default
has occurred or demand has been made, without notice to any Obligor, or
compliance with any other condition precedent now or hereafter imposed by
statute, rule of law, or otherwise (all of which are hereby expressly waived)
be set off, appropriated and applied by such Lender against any and all of
the Obligations ratably between the Lenders in proportion to the respective
pro-rata shares of the Lenders with respect to the Obligations, in such
manner as such Lender in its sole discretion may determine. The rights of
each Lender under this Section 10.3 are in addition to other rights
(including without limitation, other rights of set-off) which each Lender may
have.

10.4   INDEMNIFICATION. Each Obligor shall indemnify, defend and hold the
Administrative Agent and Lenders harmless against, of and from any claim (as
well as from attorneys' reasonable fees and expenses in connection therewith)
brought or threatened against the Administrative Agent or a Lender by such
Obligor, any guarantor or endorser of the Obligations, or any other person on
account of the Administrative Agent's or a Lender's relationship with any
Obligor, or any guarantor or endorser of the Obligations (each of which may
be defended, compromised, settled or pursued by the Administrative Agent with
counsel of the Administrative Agent's election, but at the expense of the
Obligors), except (a) in the case of the indemnification of the
Administrative Agent against a claim brought or threatened against the
Administrative Agent, for any claim arising out of the gross negligence or
willful misconduct of the Administrative Agent, as adjudged by a court of
competent jurisdiction, and (b) in the case of the indemnification of a
Lender against a claim brought or threatened against such Lender, for any
claim arising out of the gross negligence or willful misconduct of such
Lender, as adjudged by a court of competent jurisdiction, and (c) in the case
of the indemnification of the Administrative Agent or a Lender against a
claim brought against the Administrative Agent by a Lender or against a
Lender by the other Lender or by the Administrative Agent. The within
indemnification shall survive payment of the Obligations, and/or any
termination, release or discharge executed by the Administrative Agent or a
Lender in favor of any Obligor. For purposes of clarification, no Obligor
shall have any obligation to indemnify the Administrative Agent or any Lender
against any claim brought or threatened against the Administrative Agent or
any such Lender that any Obligor believes arises out of the gross negligence
or willful misconduct of the Administrative Agent or any such Lender if a
court of competent jurisdiction has determined that such claim in fact arose
out of the gross negligence or willful misconduct of the Administrative Agent
or such Lender, as the case may be. The Lenders shall be severally liable to
refund any amounts actually and voluntarily paid by the Obligors to the
Administrative Agent with respect to any such claim, promptly after such
judicial determination. Notwithstanding any provision in this Agreement to
the contrary, the Lenders and Administrative Agent agree that neither the
Lenders nor the Administrative Agent shall (1) declare an Event of Default
or accelerate the Obligations or (2) set aside or reserve any Collateral or
otherwise exercise any remedies with respect to any Collateral, in each case
based solely upon an Obligor's failure to pay the amount of any indemnifiable
claim (and/or attorneys' fees and expenses in connection therewith) prior to
such judicial determination, PROVIDED, HOWEVER,  that in the case of an Event
of Default (other than the failure to pay the amount of any indemnifiable
claim and/or attorneys' fees and expenses in connection therewith prior to
such judicial determination), the Lenders and the Administrative Agent may
accelerate the Obligations and set aside or

                                      22
<PAGE>

reserve any Collateral or otherwise exercise any remedies with respect to any
Collateral. Notwithstanding any provision in this Agreement to the contrary,
in no circumstance shall the Administrative Agent or Lenders seek
consequential, punitive or any other additional damages based upon the
failure or the alleged failure of any Obligor to pay the amount of any
indemnifiable claim and/or attorneys' fees and expenses in connection
therewith prior to such judicial determination.

10.5   COSTS AND EXPENSES. Each Obligor shall pay to the Administrative Agent
any and all costs and expenses (including, without limitation, reasonable
attorneys' fees, court costs, litigation and other expenses) incurred or paid
by the Administrative Agent or a Lender (a) in establishing, maintaining,
protecting or enforcing any of the Administrative Agent's or a Lender's
rights or the Obligations, including, without limitation, any and all such
costs and expenses incurred or paid by the Administrative Agent or a Lender
in defending the Administrative Agent's and Lenders' security interest in,
title or right to the Collateral or in collecting or attempting to collect or
enforcing or attempting to enforce payment of the Collateral, and (b) in
connection with the preparation, amendment, review, negotiation, execution
and delivery of this Agreement and the Loan Documents.

10.6   COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be an original, but all of which shall
constitute but one agreement.

10.7   BINDING EFFECT OF AGREEMENT. This Agreement shall be binding upon and
inure to the benefit of the respective heirs, executors, administrators,
legal representatives, successors and assigns of the parties hereto, and
shall remain in full force and effect (and the Administrative Agent and
Lenders shall be entitled to rely thereon) until terminated as to future
transactions by written notice from either party to the other party of the
termination hereof; provided that any such termination shall not release or
affect any Collateral in which the Administrative Agent and Lenders already
have a security interest or any Obligations incurred or rights accrued
hereunder prior to the effective date of such notice (as hereinafter defined)
of such termination. Notwithstanding any such termination, the Administrative
Agent and Lenders shall have a security interest in all Collateral to secure
the payment and performance of Obligations arising after such termination as
a result of commitments or undertakings made or entered into by the Lenders
prior to such termination. The Lenders may, with the prior written approval
of Borrower (which shall not be unreasonably withheld or delayed), transfer
and assign this Agreement and deliver the Collateral to the assignee, who
shall thereupon have all of the rights of the Lenders; and the Administrative
Agent and Lenders shall then be relieved and discharged of any responsibility
or liability with respect to this Agreement and the Collateral. The Lenders
may, with the prior written approval of Borrower (which shall not be
unreasonably withheld or delayed), from time to time grant participation
interests in the Loans in minimum amounts of $1,000,000 which shall not
relieve the Lenders of any obligations or liability hereunder with respect to
the making of Revolving Loans, and notwithstanding the grant of any such
participation interests, the Borrower and the other Obligors, except as
otherwise provided herein, may look solely to the Administrative Agent as the
agent for all participants for purposes of obtaining the consent, waiver or
agreement of Lenders to any action or amendment of the Loan Documents and for
purposes of the delivery of notice thereunder.

10.8   FURTHER ASSURANCES. Each Obligor will from time to time execute and
deliver to the Administrative Agent, and take or cause to be taken, all such
other further action as the Administrative Agent may request in order to
effect and confirm or vest more securely in the Lenders or Administrative
Agent all rights contemplated or to vest more fully in or assure to the
Lenders or Administrative Agent the security interest in the Collateral
granted to the Administrative Agent and the Lenders by this Agreement or to
comply with applicable statutes or law and to facilitate the collection of
the Collateral.

10.9   AMENDMENTS AND WAIVERS. This Agreement may be amended and any Obligor
may take any action herein prohibited, or omit to perform any act herein
required to be performed by it, if such Obligor shall obtain the Lenders'
prior written consent to each such amendment, action or omission to act. No
delay or omission on the part of a Lender or the Administrative Agent in
exercising any right hereunder shall operate as a waiver of such right or any
other right, and waiver on any one or more occasions shall not be construed
as a bar to or waiver of any right or remedy of a Lender or the
Administrative Agent on any future occasion.

10.10  TERMS OF AGREEMENT. This Agreement shall continue in force and effect
so long as any Obligations or obligation of any Obligor to the Lenders or
Administrative Agent shall be outstanding and is supplementary to each and
every other agreement between any Obligor and Lenders and/or Administrative
Agent and shall not be so construed as to limit or otherwise derogate from
any of the rights or remedies of Lenders or the Administrative

                                      23
<PAGE>

Agent any of the liabilities, obligations or undertakings of any Obligor
under any such agreement, nor shall any contemporaneous or subsequent
agreement between any Obligor and a Lender and/or the Administrative Agent be
construed to limit or otherwise derogate from any of the rights or remedies
of Lenders or the Administrative Agent or any of the liabilities, obligations
or undertakings of any Obligor hereunder, unless such other agreement
specifically refers to this Agreement and expressly so provides.

10.11  NOTICES. Any notices under or pursuant to this Agreement shall be
deemed duly received and effective if delivered in hand to any officer of
agent of any Obligor or Lenders or the Administrative Agent, as applicable,
or if mailed by registered or certified mail, return receipt requested,
addressed to any Obligor or Lenders or the Administrative Agent, as
applicable, at the addresses set forth in this Agreement or as any party may
from time to time designate by written notice to the other parties, on the
third business day after such mailing.

10.12  MASSACHUSETTS LAW. This Agreement is intended to take effect as a
sealed instrument and has been executed or completed and is to be performed
in Massachusetts, and it and all transactions thereunder or pursuant thereto
shall be governed as to interpretation, validity, effect, rights, duties and
remedies of the parties thereunder and in all other respects by the domestic
laws of Massachusetts.

10.13  REPRODUCTIONS. This Agreement and all documents which have been or may
be hereinafter furnished by any Obligor to the Lenders and the Administrative
Agent may be reproduced by the Lenders and the Administrative Agent by any
photographic, photostatic, microfilm, xerographic or similar process, and any
such reproduction shall be admissible in evidence as the original itself in
any judicial or administrative proceeding (whether or not the original is in
existence and whether or not such reproduction was made in the regular course
of business).

10.14  VENU. Each Obligor irrevocably submits to the nonexclusive
jurisdiction of any federal or state court sitting in Massachusetts, over any
suit, action or proceeding arising out of or relating to this Agreement. Each
Obligor irrevocably waives, to the fullest extent it may effectively do so
under applicable law, any objection it may now or hereafter have to the
laying of the venue of any such suit, action or proceeding brought in any
such court and any claim that the same has been brought in an inconvenient
forum. Each Obligor irrevocably appoints the Secretary of State of the
Commonwealth of Massachusetts as its authorized agent to accept and
acknowledge on its behalf any and all process which may be served in any such
suit, action or proceeding, consents to such process being served (i) by
mailing a copy thereof by registered or certified mail, postage prepaid,
return receipt requested to such Obligor and (ii) by serving the same upon
such agent, and agrees that such service shall in every respect be deemed
effective service upon such Obligor.

10.15  JURY WAIVER. EACH OF THE OBLIGORS, LENDERS AND THE ADMINISTRATIVE
AGENT HEREBY KNOWINGLY, VOLUNTARILY AND INTENTIONALLY, AND AFTER AN
OPPORTUNITY TO CONSULT WITH LEGAL COUNSEL, WAIVES ANY AND ALL RIGHTS TO A
TRIAL BY JURY IN ANY ACTION OR PROCEEDING IN CONNECTION WITH THIS AGREEMENT,
THE OBLIGATIONS, ALL MATTERS CONTEMPLATED HEREBY AND DOCUMENTS EXECUTED IN
CONNECTION HEREWITH. EACH OBLIGOR CERTIFIES THAT NEITHER THE LENDERS NOR THE
ADMINISTRATIVE AGENT NOR ANY OF THEIR REPRESENTATIVES, AGENTS OR COUNSEL HAS
REPRESENTED, EXPRESSLY OR OTHERWISE, THAT THE LENDERS OR THE ADMINISTRATIVE
AGENT WOULD NOT IN THE EVENT OF ANY SUCH PROCEEDING SEEK TO ENFORCE THIS
WAIVER OF RIGHT TO TRIAL BY JURY.

                                      24
<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first written above.

Witness                                OBLIGORS:

                                       SeraCare, Inc.


    /s/ Jerry L. Burdick               By:         /s/ Barry D. Plost
------------------------------              ---------------------------------
                                            Barry D. Plost, Chairman and CEO


                                       Avre Incorporated


    /s/ Jerry L. Burdick               By:         /s/ Barry D. Plost
------------------------------              ---------------------------------
                                            Barry D. Plost, Chairman and CEO


                                       Binary Associates, Inc.


    /s/ Jerry L. Burdick               By:         /s/ Barry D. Plost
------------------------------              ---------------------------------
                                            Barry D. Plost, Chairman and CEO


                                       SeraCare Acquisitions, Inc.


    /s/ Jerry L. Burdick               By:         /s/ Barry D. Plost
------------------------------              ---------------------------------
                                            Barry D. Plost, Chairman and CEO


                                       BHM Labs, Inc.


    /s/ Jerry L. Burdick               By:         /s/ Barry D. Plost
------------------------------              ---------------------------------
                                            Barry D. Plost, Chairman and CEO


                                       SeraCare Technology, Inc.


    /s/ Jerry L. Burdick               By:         /s/ Barry D. Plost
------------------------------              ---------------------------------
                                            Barry D. Plost, Chairman and CEO


<PAGE>

                                       The Western States Group, Inc.

    /s/ Jerry L. Burdick               By:         /s/ Barry D. Plost
------------------------------              ---------------------------------
                                            Barry D. Plost, Chairman and CEO


                                       American Plasma, Inc.


    /s/ Jerry L. Burdick               By:         /s/ Barry D. Plost
------------------------------              ---------------------------------
                                            Name:  Barry D. Plost
                                            Title: Chairman and CEO







                                       Brown Brothers Harriman & Co.


    /s/ [ILLEGIBLE]                    By:         /s/ Joseph E. Hall
------------------------------              ---------------------------------
                                            Name:  Joseph E. Hall
                                            Title: Deputy Manager


                                       State Street Bank and Trust Company


    /s/ [ILLEGIBLE]                    By:         /s/ Bruce S. Daniels
------------------------------              ---------------------------------
                                            Name:  Bruce S. Daniels
                                            Title: VP


                                       Brown Brothers Harriman & Co., as
                                         Administrative Agent


    /s/ [ILLEGIBLE]                    By:         /s/ Joseph E. Hall
------------------------------              ---------------------------------
                                            Name:  Joseph E. Hall
                                            Title: Deputy Manager

<PAGE>

                                      EXHIBIT A

                       LENDERS' COMMITMENTS AND PRO-RATA SHARES

<TABLE>
<CAPTION>
Lender                        Revolving Loan      Term Loan      Pro-Rata Share
------                        Commitment          Commitment     --------------
                              --------------      ----------
<S>                          <C>                 <C>            <C>
Brown Brothers                $5,000,000          $3,500,000     50%
Harriman & Co.


State Street Bank and         $5,000,000          $3,500,000     50%
Trust Company
---------------------------   -----------------   ------------   --------------
Aggregates:                   $10,000,000         $7,000,000     100%

</TABLE>

<PAGE>

                                      EXHIBIT B

                                   SeraCare, Inc.
                             BORROWING BASE CERTIFICATE

     To: Brown Brothers Harriman & Co. and State Street Bank and Trust
Company (collectively the "Lenders") under a certain Revolving Credit, Term
Loan and Security Agreement dated as of December ___, 1998 (the "Loan
Agreement"), by and among the Lenders: Brown Brothers Harriman & Co. as
Administrative Agent for the Lenders; SeraCare, Inc. (the "Borrower"); Avre
Incorporated; Binary Associates, Inc.; SeraCare Acquisitions, Inc.; BHM
Labs, Inc.; SeraCare Technology, Inc.; The Western States Group, Inc. and
American Plasma, Inc.

     Terms used in this certificate shall have the same meaning as ascribed
thereto in the Loan Agreement.

     The undersigned officers of the Borrower certify that the information
furnished herein as of _______________ 1998 is true and correct and that as
of the date hereof no Event of Default, or event which after notice or lapse
of time or both would be an Event of Default, under the Loan Agreement has
occurred.

     COMPUTATION OF BORROWING BASE
     -----------------------------

(a)  Accounts Receivable(*) of SeraCare Biologics division
     (excluding Accounts Receivable from Grifois, S.A.)
     excluding invoices over 90 days from invoice date        __________________

(b)  Accounts Receivable(*) of The Western States Group, Inc.
     excluding invoices over 90 days from invoice date        __________________

(c)  Accounts Receivable(*) of Consolidated Technologies, Inc.
     excluding invoices over 90 days from invoice date        __________________

(d)  Accounts Receivable(*) from Grifois S.A.
     excluding invoices over 90 days from invoice date        __________________

(e)  Other Accounts Receivable(*)
     excluding invoices over 90 days from invoice date        __________________

(f)  Sub Total (total of (a), (b), (c), (d) and (e)           __________________

(g)  Foreign Accounts Receivable included in (f) that
     are not due from Grifois or not backed by a letter
     of credit                                                __________________

(h)  Amount in (g) less 25% of the amount in (f), but
     not less than $0.                                        __________________

(i)  Qualifying Accounts Receivable ( = (f) minus (h))        __________________

(j)  Qualifying Accounts Receivable Times 75%                 __________________

(k)  Lessor of Inventory times 50% or $7,500,000              __________________

(l)  Total of (j) plus (k)                                    __________________

(m)  Maximum Revolving Loan Amount                            __________________

(n)  Net Amount Available (lessor of (l) or (k)               ==================

(*) ACCOUNTS RECEIVABLE SHALL EXCLUDE: amounts for which an offset, charge or
lien has been asserted; amounts for debtors who are insolvent, bankrupt or
have been turned over for collection.

VALUE OF CERTAIN INVENTORIES
----------------------------
BHM Labs -- Ft Smith Arkansas                                 ___________
American Plasma, Inc. -- Canal Street, Houston Texas          ___________
American Plasma, Inc. -- West Bellfort, Houston Texas         ___________
American Plasma, Inc. -- South Shaver, South Houston Texas    ___________


By ______________________________________            Date________________
   Authorized Signer

<PAGE>

                                      EXHIBIT C

                           COVENANT COMPLIANCE CERTIFICATE

     The undersigned hereby certifies to Brown Brothers Harriman & Co.
("Brown Brothers"), in connection with that certain Revolving Credit, Term
Loan and Security Agreement, dated as of ____________, 1998 (the "Loan
Agreement") among Brown Brothers, State Street Bank and Trust Company, Brown
Brothers Harriman & Co. as Administrative Agent, SeraCare, Inc. ("SeraCare"),
Avre Incorporated ("Avre"), Binary Associates, Inc. ("Binary"), SeraCare
Acquisitions, Inc. ("Acquisitions"), BHM Labs, Inc. ("BHM"), SeraCare
Technology, Inc. ("Technology"), The Western States Group, Inc. ("Western"),
and American Plasma, Inc. (and along with SeraCare, Avre, Binary,
Acquisitions, BHM Technology and Western, each an "Obligor" and collectively
the "Obligors"), that the undersigned is the duly elected and acting
_____________ of SeraCare, Inc., a California corporation, and that, as of
the date hereof, (i) each Obligor is in full and complete compliance with
each of the affirmative covenants set forth in Section 6 of the Loan
Agreement and with each of the negative covenants set forth in Section 7 of
the Loan Agreement, and (ii) there are no existing uncured Events of Default
under Section 8 of the Loan Agreement.

     WITNESS my hand and seal as of ______________________, 1998.



                                          _________________________________

<PAGE>

                                 SCHEDULE 5.2


SERACARE, INC. - a Delaware corporation
               Parent Company

100% owned subsidiaries:


               AVRE, INC. - a Nevada corporation
               Acquired October 1993
               Owns and operates plasma collection centers.

               BINARY ASSOCIATES, INC. - a Colorado corporation
               Acquired October 1993
               Owns and operates plasma collection centers.

               BHM LABS, INC. - an Arkansas corporation
               Acquired July 1996
               Owns and operates plasma collection center.

               SERACARE ACQUISITIONS, INC. - a Nevada corporation
               Established in June 1996

               SERACARE TECHNOLOGY, INC. - a Nevada corporation
               Established in January 1998
               DBA: Consolidated Technologies

               WESTERN STATES GROUP, INC. - a California corporation
               Acquired in February 1998

               AMERICAN PLASMA, INC. - a Texas corporation
               Acquired in September 1998


                                     1
<PAGE>

                                 SCHEDULE 5.4



TITLE TO REAL AND PERSONAL PROPERTY:

EXCEPTIONS TO GOOD AND CLEAR TITLE:

1.   In the November 29, 1997 American Plasma acquisition, SeraCare acquired
     three properties located in Salt Lake City, Utah; South Bend, Indiana and
     Kalamazoo, Michigan. O'Melveny & Myers LLP has been working on the title
     transfer which has not yet been accomplished. There is a mortgage on the
     Salt Lake City location which is listed on SCHEDULE 5.4a. There is a
     carryover title issue relating to a prior owner which is in the process of
     being clarified and which has caused the delay.

2.   Each of the plasma collection centers has Haemonetics Plasmapheresis
     machines which are used during the plasma collection process. None of these
     machines are owned. Such machines are provided by Haemonetics on a "Loaned"
     basis and are Loaned conditional upon the company purchasing "softgoods"
     used by the machines during the collection process for Haemonetics.

3.   Please refer to SCHEDULES 5.4a and 5.4b which are hereby incorporated
     herein by such reference.


                                       2
<PAGE>

                                 SCHEDULE 5.4(a)


1.   Mortgage:

Salt Lake City
606 W. North Temple
Salt Lake City, UT 84116

Mortgage held by:
Zions First National Bank
P.O. Box 25822
Salt Lake City, UT 84125
Loan Number: 1094408-9004

2.   Certain of the Collateral located at American Plasma, Inc.'s facilities is
     subject to the following liens:

               -    A UCC 1 financing statement secures Alpha Therapeutic
                    Corporation's interest in the plasma softgood setups and
                    supplies for use at the following donor center locations:

                         Beaumont, TX; Case Grande, AZ; Houston, TX (4
                         locations); Longview, TX.

               -    A UCC 1 financing statement secures Jerry J. Moore
                    Investments' interest in all property placed in the demised
                    premises at 3316 # 1 South Shaver, South Houston, TX 77504.

               -    A UCC 1 financial statement secures Weingarten Realty
                    Investors' interest in all property placed in the leased
                    premises at 8550 West Bellfort, Houston, TX 77071.

               -    A UCC 1 financing statement secures Weingarten Realty
                    Investors' interest in all property placed in the leased
                    premises at 8542 West Bellfort, Houston, TX 77071.

               -    A UCC 1 financing statement secures Samuel H. Summer's
                    interest (as assigned from Plasmalab Donor Centers, Inc.) in
                    certain of the assets of American Plasma Services, L.P.
                    American Plasma, Inc. is the successor to American Plasma
                    Services, L.P.

               -    American Plasma Services, L.P. has granted a security
                    interest in certain of its collateral to Nathaniel Summer,
                    pursuant to that certain Security Agreement, dated June 10,
                    1996, by and between American Plasma Services, L.P. and
                    Nathaniel Summer. American Plasma, Inc. is the successor to
                    American Plasma Services, L.P.

               -    American Plasma Services, L.P. has granted a security
                    interest in certain of its collateral to Plasmalab Donor
                    Centers, Inc., pursuant to that certain Security


                                       3
<PAGE>

                    Agreement, dated April 23, 1996, by and between American
                    Plasma Services, L.P. and Plasmalab Donor Centers, Inc.
                    American Plasma, Inc. is the successor to American Plasma
                    Services, L.P.

3.   Each of the leases for the following facilities contain contractual
provisions providing the lessor therein with a security interest in all of the
property of American Plasma, Inc. located at the respective facility:

               -    2219 Canal Street, Houston, Texas 77003 -- Walter A. Smith
                    Paving Contractor (Lessor)

               -    1223 West 43rd Street, Houston, Texas 77018 -- Shocen, Ltd.
                    (Lessor)

               -    2209 Calder Avenue, Beaumont, Texas 77702 -- Ardmore
                    Addition (Lessor)

               -    1725 High Street, Longview, Texas 75602 -- Naseep Thomas
                    (Lessor)

4.   Pecks Management Partners Ltd. has a security interest in all of the
property and assets of SeraCare and/or its subsidiaries. This security interest
is subordinate to any and all bank debt of SeraCare and/or its subsidiaries.

5.   SeraCare, Inc. has pledged all of the assets of BHM Labs, Inc. to the
holders of certain of SeraCare, Inc.'s preferred stock. In connection with such
pledge, such holders also have possession of the certificates representing all
of the outstanding capital stock of BHM Labs, Inc.


                                       4
<PAGE>

                                  SCHEDULE 5.4b


PERSONAL PROPERTY LEASES:

PLASMA OPERATIONS - No material personal property leases other than copiers.
                  - See attached for facility leases.

WESTERN STATES GROUP, INC. - No material personal leases other than copier.
                           - See attached for facility lease.

AMERICAN PLASMA, INC. - Equipment lease for 12 PCS (plasma collection devices)
from Haemonetics Corp. at $3,347.86 per month. No other material personal leases
other than copiers.
                      - See attached for facility leases.

CONSOLIDATED TECHNOLOGIES:
Facilities - Teachers Realty Corporation
             Current Amendment Term: Shall end on November 14, 1999
             Renewal Option: One Additional Term of Five Years
             Monthly Rent Currently Paid: 48.6 cents per Sq. Ft. ($9,094.52)
             Location is the Home Office/Manufacturing Facility in Austin,
             Texas.

Machinery(*)   BT Finance, Inc.              - Various equipment       $  161.73
               Beckman Instruments           - Various equipment       $1,792.50
               GE Capital                    - Various equipment       $  796.00
               Trinity Capital Corp.         - Various equipment       $2,662.65
               Ionics Ahlfinger Water Co.    - Water purifier          $  100.00
               Abbott Laboratories           - Clinical Chemistry      $8,258.39
               Affiliated Corporate Services, Inc. - Various equipment $1,796.91

               (*)All above (except the Abbott Laboratories lease) are
renewable or have buyout provisions


                                       5
<PAGE>

                                  PLASMA OPERATIONS
                            SCHEDULE OF FACILITIES LEASES
<TABLE>
<CAPTION>
CENTER                      LANDLORD           CURRENT MNTHLY. RENT           TERM
-------------------------------------------------------------------------------------------------------

BINARY ASSOCIATES, INC.
-------------------------------------------------------------------------------------------------------
<S>                 <C>                         <C>                   <C>
BATON ROUGE, LA     RR Company of America, LLC      $3,500.00         12/1/98 - 11/30/03
                    PO Box 60100                                      with two 5-year options to renew
                    Lafayetta, LA 70596-0100

CLARKESVILLE, TN    Dale Gallinatti                 $4,653.98         12/24/92 - 12/24/2002
                    119 Calle La Mesa                                 with 5-year option to renew
                    Moraga, CA 94556

                    Larry Cary
                    32 Woodridge Drive
                    Colorado Springs, CO 80906

LAS VEGAS, NV       Hy Moss                         $5,200.00         6/1/93 - 5/31/99
                    6971 Monte Rosa                                   with 2-year option to renew
                    Las Vegas, NV 89120

                    610 LLC                         $2,000.00         Month-to-month (terminates
                    860 East Sahara Avenue                            effective 12/31/98)
                    Las Vegas, NV 89104                               Former center used as storage

RENO #1             Wu Investment Co.               $5,000.00         11/1/98 - 10/31/03
                    4829 Geary Blvd.                                  with 5-year option to renew
                    San Francisco, CA 94118

CORPORATE OFFICES   Watt Management Co.             $3,836.25         5/20/96 - 5/20/99
                    1875 Century Park East
                    Suite 1110
                    Los Angeles, CA 90067

AVRE, INC.
-------------------------------------------------------------------------------------------------------
COLORADO SPRINGS    Delta & Bijou Property Mgmt.    $2,370.69         8/1/95 - 7/31/2000
                    2140 Crystal River Drive                          Former center exchanged with
                    Colorado Springs, CO 80915                        Serological, Inc. attempting to
                                                                      sublease
</TABLE>


                                       6
<PAGE>

<TABLE>
<CAPTION>
CENTER                      LANDLORD            CURRENT MNTHLY. RENT           TERM
-------------------------------------------------------------------------------------------------------
<S>                 <C>                               <C>               <C>

PHOENIX             Harry Tang                        $2,000.00         6/1/98 - 5/30/03
                    20943 Brand Avenue                                  Two five year renewal options
                    Long Beach, CA 90810
                    (310) 537-6624

WESTERN STATES
GROUP, INC.
-------------------------------------------------------------------------------------------------------

OCEANSIDE, CA       Del Oro Gateway Partners, L.P.    $3,224.32         8/1/98 - 7/31/03
                    1947 Camino Vida Roble, Suite                       One five year renewal option
                    104, Carlsbad, California 92008

SERACARE
TECHNOLOGY, INC.
-------------------------------------------------------------------------------------------------------

AUSTIN, TX          TIAA Realty, Inc.                 $24,658.82        Lease expires 11/14/99
                    C/o Transwestern Property                           One five year renewal option
                    Company
                    901 S. MoPac, Bldg One, Suite 520
                    Austin, TX 78746

BHM LABS, INC.
-------------------------------------------------------------------------------------------------------

FT. SMITH, AR       Gene Wahl                         $1,200.00         1/7/96 - 6/30/2001
                    P.O. Box 2124                                       5 YEARS RENEWAL OPTION.
                    Fort Smith, AR 72902                                Vacant - attempting to sublease
                    (501) 782-3053

                    Simi Biological Resources, Inc.   $1,990.00         5/1/98 - 4/30/03
                    1590 South Ocean Line, Unit 123                     5-year renewal option
                    Ft. Lauderdale, FL 33316

SERACARE
ACQUISITIONS, INC.
-------------------------------------------------------------------------------------------------------

MACON, GA           Thornton Realty Co.               $3,750.00         9/1/96 - 8/31/2001
                    686 Poplar St. Box T                                10 YEARS RENEWAL OPTION
                    Macon, GA 31202
                    (912) 745-1677

TOLEDO, OHIO        Eugene L. Buckland                $1,895.00         10/1/96 - 9/30/2001
                    1717 Green Valley                                   10 YEARS RENEWAL OPTION
                    Toledo, OH 43614
                    (419) 513-9977
</TABLE>


                                       7

<PAGE>

<TABLE>
<CAPTION>
CENTER                      LANDLORD            CURRENT MNTHLY. RENT           TERM
-------------------------------------------------------------------------------------------------------
<S>                 <C>                             <C>                 <C>
CLEARFIELD, UT      The Kier Corporation              $4,391.25         9/20/96 - 9/20/2006
                    3710 Quincy, Avenue                                 5 YEARS RENEWAL OPTION
                    Ogden, UT 84403

RALEIGH, NC         James Levinson                    $2,500.00         6/1/98 - 5/30/03
                    P.O. Box 117
                    Benson, NC 27504

PASCO, WA           201 Associates                    $2,000-00         9/15/96 - 9/14/2001
                    c/o William Rill                                    5-year renewal option
                    P.O. Box 197                                        Option to Purchase
                    Port Orchard, WA 98366

SAVANAH, GA         Mr. Donald Amerson                $4,500.00         7/1/97 - 6/20/2002
                    P.O. Box 13354                                      10 YEARS RENEWAL OPTION
                    Savannah, GA 31416

POCATELLO, ID       Coldwell Banker Landmark          $1,860.00         7/11/97 - 4/30/2003
                    920 Dean Drive, Suite C
                    Pocatello, ID 83201

BOISE, ID           Larry Stevens                     $3,350.00         8/1/98 - 12/31/03
                    100 North 9th Street, Suite 200                     Two 5-year renewal options
                    Boise, ID 83702

RENO #2             Angelina Capurro                  $2,500.00         Month-to-month
                    5005 Longley Lane
                    Reno, NV 89511

WILMINGTON, DE      Leon N. Weiner & Associates,      $4,904.50         1/26/98 - 1/25/2003
                    Inc.                                                5 YEARS RENEWAL OPTION
                    4 Denny Road
                    Wilmington, DE 19809
                    (302) 764-9430

PORT ARTHUR, TX     Daryl Burke & Adrian Scallan      $3,000.00         7/1/98 - 6/30/03
                    1348 Ninth Avenue                                   Two five year renewal options
                    Port Arthur, Texas
</TABLE>

                                       8
<PAGE>

<TABLE>
<CAPTION>
CENTER                      LANDLORD            CURRENT MNTHLY. RENT           TERM
-------------------------------------------------------------------------------------------------------

AMERICAN PLASMA, INC.
-------------------------------------------------------------------------------------------------------
<S>                 <C>                               <C>               <C>
2219 CANAL STREET   Walter A. Smith                   $2,786.43         10/1/94 - 9/30/99
HOUSTON, TX         Paving Contractors
                    2111 Canal
                    Houston, Texas 77003

1223 WEST 43RD      Shocen, Ltd                       $5,192.34         2/1/97 - 1/31/04
STREET              5718 Westheimer, Suite 800
HOUSTON, TX         Houston, Texas 77057

3316 #1, SOUTH      Jerry J. Moore Investments        $6,230.00         11/1/96 - 8/31/07
SHAVER, SOUTH       7880 San Felipe Ste 100
HOUSTON, TX         Houston, Texas 77063

2209 CALDER         Ardmore Addition                  $1,881.00         9/7/96 - 9/6/00
AVENUE              240 Crockett Street
BEAUMONT, TX        Beaumont, Texas 77701

1725 SOUTH HIGH     Mrs. Naseep Thomas                $2,250.00         7/1/98 - 6/30/99
STREET              c/o Thomas A. Sweeny & Assoc.
LONGVIEW, TX        P.O. Box 3172
                    Longview, Texas 75606

8542 W. BELLFORT    Weingarten Realty Investors         $992.58         12/5/97 - 7/31/99
HOUSTON, TX         P.O. Box 924133
                    Houston, Texas 77292-4133

8550 W. BELFFORT    Weingarten Realty Investors       $3,449.00         8/1/98 - 7/31/99
HOUSTON, TX         P.O. Box 924133
                    Houston, Texas 77292-4133

719 SAWDUST ROAD    Gazal Development Corporation     $3,890.00         11/1/96 - 10/31/99
SUITE 205           719 Sawdust Road, Suite 100
SPRING, TX          Spring, Texas 77380

565 SOUTH DOBSON    Dobson Road Partners              $4,973.00         4/1/98 - 3/31/03
ROAD, SUITES 13-16  c/o Hannay Investment Properties
MESA, AZ            4651 East Palomino
                    Phoenix, Arizona 85018

3701 PLAINS BLVD.   Omni Capital Corporation          $2,200.00         9/1/98 - 8/31/00
#21, AMARILLO, TX   1715 West 58th
                    Amarillo, Texas 79110
</TABLE>


                                       9
<PAGE>

<TABLE>
<CAPTION>
CENTER                      LANDLORD            CURRENT MNTHLY. RENT           TERM
-------------------------------------------------------------------------------------------------------
<S>                 <C>                               <C>               <C>
417 NORTH           Barnes & Halliburton              $1,312.41         1/1/97 - 12/31/99
FLORENCE STREET     1577 North Pinal Avenue
CASE GRANDE, AZ     Case Grande, Arizona 85222

4014-4020 N. 19TH   Samuel & Jeanie Summer            $4,781.43         4/23/96 - 4/22/06
AVE-, PHOENIX, AZ   6058 E. Evening Glow Dr.
                    Scottsdale, Arizona 85262

12734 WOODFOREST    Vezcor, Inc.                      $4,271.25         11/1/95 - 10/31/00
BOULEVARD           c/o Tarantino Properties, Inc.
HOUSTON, TX         7887 San Felipe #237
                    Houston, Texas 77063
</TABLE>


                                      10

<PAGE>

                                 SCHEDULE 5.7


1.     American Plasma Services, L.P. has granted a security interest in
certain of its collateral to Plasmalab Donor Centers, Inc., pursuant to that
certain Security Agreement, dated April 23, 1996, by and between American Plasma
Services, L.P. and Plasmalab Donor Centers. Inc. (the "PLASMALAB SECURITY
AGREEMENT"). American Plasma, Inc. is the successor to American Plasma Services,
L.P. Sections 1, 2 and 3 of the Plasmalab Security Agreement prohibit and/or
require the prior consent of Plasmalab Donor Centers, Inc. (which consent shall
not be unreasonably withheld) before granting additional security interests (or
authorizing, executing or filing financing, statements with respect to such
additional security interests) in the collateral which is subject to the
Plasmalab Security Agreement.

2.     American Plasma Services, L.P. has granted a security interest in
certain of its collateral to Nathaniel Summer, pursuant to that certain Security
Agreement, dated June 10, 1996, by and between American Plasma Services, L.P.
and Nathaniel Summer (the "SUMMER SECURITY AGREEMENT"). American Plasma, Inc. is
the successor to American Plasma Services, L.P. Sections 1, 2 and 3 of the
Summer Security Agreement prohibit and/or require the prior consent of Nathaniel
Summer (which consent shall not be unreasonably withheld) before granting
additional security interests (or authorizing, executing or filing financing
statements with respect to such additional security interests) in the collateral
which is subject to the Summer Security Agreement.

               Except as disclosed in Items 1 and 2 to this SCHEDULE 5.7, there
is no provision in any indenture, contract or agreement to which any Obligor is
a party which prohibits the execution, delivery or performance of the Loan
Documents. However, the contracts and agreements set forth on Schedule 5.4(a)
provide for liens and encumbrances on certain of the Collateral, as set forth on
such Schedule.


                                      11
<PAGE>

                                 SCHEDULE 5.8

1.     SeraCare Acquisitions. Inc. does not currently have a FDA license for
its Toledo. Ohio or Pasco, Washington facilities. Both facilities are currently
operating under a reference number pending the issuance of the FDA license for
each entity.

1.     SeraCare Acquisitions. Inc. does not currently have QPP certification
for its Port Arthur, Texas or Savanah, Georgia facilities. SeraCare
Acquisitions, Inc. is in the process of obtaining such certification for both
such facilities, however, six months of operations are required before a
facility can receive QPP certification.

                                      12
<PAGE>

                                 SCHEDULE 5.12

TITLE TO COLLATERAL

1.  SCHEDULES 5.4, 5.4a and 5.4b are incorporated herein by reference.

          -    Following the grant of a security interest in the Collateral to
               the Lender as contemplated by the Loan Documents, the Borrower
               will be required to grant to Pecks Management Partners, Ltd., as
               agent for the holders of the Borrower's 12% Senior Subordinated
               Debentures due 2005, a security interest in the Borrower's and
               each other Obligor's assets.

2.  See Item 5 of SCHEDULE 5.4(a) which is incorporated herein by reference.


                                      13
<PAGE>

                                  SCHEDULE 5.13

                              LOCATION OF COLLATERAL

See Item 5 of Schedule 5.4(a) which is incorporated herein by reference.

LOCATION

SERACARE, INC.

CORPORATE OFFICES (this is also the location of the corporate records of each of
Avre, Inc., BHM Labs, Inc., Binary Associates, Inc. and SeraCare Acquisitions,
Inc.)
1925 Century Park East
Suite 1970
Los Angeles, CA 90067

BINARY ASSOCIATES, INC.

LAS VEGAS
611 N. Las Vegas Blvd.
Las Vegas, NV 89101

CLARKESVILLE
1174 Ft. Campbell Blvd.
Clarkesville, TN 37042

RENO #1
513 E. 2nd Street
Reno, NV 89502

BATON ROUGE
4226 Plank Road
Baton Rouge, Louisiana 70805

BHM LABS, INC.

FORT SMITH
910 N. 32nd Street
Ft. Smith, AR 72903

AVRE, INC.

PHOENIX
3529 McDowell
Phoenix, AZ 85029


                                      14
<PAGE>

SERACARE ACQUISITIONS, INC.

CLEARFIELD
375 South State
Clearfield, UT 84015

RALEIGH
1 Maiden Lane
Raleigh, NC 27607

MACON
542 First Street
Macon, GA 31201

PASCO
745 W. Court Street
Pasco, WA 99301

TOLEDO
2540 Dorr Street
Toledo, OH 43607

POCATELLO
425 E. Center Street
Pocatello, ID 83706

SALT LAKE CITY
606 W. North Temple
Salt Lake City, UT 84116

RENO #2
785 E. 2nd Street
Reno, NV 89502

SOUTH BEND
515 Lincoln Way Street
South Bend, IN 46601

BOISE
4017 Overland
Boise, ID 83705

KALAMAZOO
705 North Park Street
Kalamazoo, MI 49007


                                      15
<PAGE>

SAVANAH
8805 White Bluff Road
Suite G, H & J
Savanah, GA 31406

WILMINGTON
Adams Four Shopping Center
4th & Adams Streets
Wilmington, DE 19801

PORT ARTHUR
1348 9th Avenue
Port Arthur, Texas 77642

SERACARE TECHNOLOGY, INC.

2170 Woodward Street
Austin, TX 78744

WESTERN STATES GROUP, INC.

1935 Avenida del Oro
Suite F
Oceanside, CA 92056

AMERICAN PLASMA, INC.

CANAL STREET
2219 Canal Street
Houston, Texas 77003

WEST 43RD
1223 West 43rd Street
Houston, Texas 77018

SOUTH SHAVER
3316 #1, South Shaver
South Houston, Texas 77504

CALDER AVENUE
2209 Calder Avenue
Beaumont, Texas 77702

SOUTH HIGH STREET
1725 South High Street
Longview, Texas 75602


                                      16
<PAGE>


8542 W. BELLFORT
8542 W. Belfort
Houston, Texas 77071

8550 W. BELLFORT
8550 W. Belfort
Houston, Texas 77071

SAWDUST ROAD
719 Sawdust Road, Suite 205
Spring, Texas 77380

SOUTH DOBSON ROAD
565 South Dobson Road
Suites 13-16
Mesa, Arizona 85202

PLAINS BLVD.
3701 Plains Blvd.
#21 Amarillo, Texas 79102

NORTH FLORENCE STREET
417 North Florence Street
Case Grande, Arizona 85222

N. 19TH AVE.
4014-4020 N. 19th Ave.
Phoenix, Arizona 85015

WOODFOREST BOULEVARD
12734 Woodforest Boulevard
Houston, Texas 77015

PUBLIC WAREHOUSE (USED BY SERACARE ACQUISITIONS, INC., THE WESTERN STATES GROUP,
INC., BINARY ASSOCIATES, INC., AVRE, INC. AND BHM LABS, INC.):

AMERICAN COLD STORAGE
Louisville Division
607 Industry Road
Louisville, KY 40201-2287


                                      17
<PAGE>

                                  SCHEDULE 5.17

            On June 29, 1998, SeraCare, Inc. filed a Registration Statement
on Form S-3 under the Securities Act of 1933 with the Securities and Exchange
Commission.


                                       18
<PAGE>

                                  SCHEDULE 5.21

            SeraCare, Inc. has an application pending with the U.S. Patent
and Trademark Office for a trademark to the name "SeraCare" and design.


                                        19