Document:

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                                                                   EXHIBIT 10.24

                                                                  EXECUTION COPY

                                    GUARANTY

         To induce (i) The Beckman Family Trust, a revocable living trust
created pursuant to the laws of the State of California (the "Trust"); (ii)
David Alan Beckman, an individual resident of the State of California, in his
individual capacity and in his capacity as Co-Trustee of the Trust ("D.
Beckman"); (iii) Keiko Koga Beckman, an individual resident of the State of
California, in her individual capacity and in her capacity as Co-Trustee of the
Trust ("K. Beckman" and together with D. Beckman, the "Beckmans"); and (iv)
Falcon International Investment Holdings LLC, a Delaware limited liability
company (the "Shareholder" and together with the Trust and the Beckmans, the
"Sellers"), to enter into (x) that certain Securities Purchase Agreement, dated
the date hereof (the "US Purchase Agreement"), by and among Serologicals
Research Products, Inc., a Delaware corporation ("Serologicals"), and the
Shareholder; (y) that certain European Purchase Agreement, dated the date hereof
(the "European Purchase Agreement"), by and among Serologicals and the
Shareholder; and (z) that certain Indemnification Agreement, dated the date
hereof (the "Indemnification Agreement"), among Serologicals, the Trust, the
Beckmans and the Shareholder (the US Purchase Agreement, the European Purchase
Agreement and the Indemnification Agreement, as at any time modified or amended
in accordance with the terms thereof, are referred to hereinafter collectively
as the "Operative Documents."), and for other good and valuable consideration,
the receipt, adequacy and sufficiency of which are hereby acknowledged,
Serologicals Corporation, a Delaware corporation ("Guarantor"), intending to be
legally bound, hereby irrevocably guarantees to Sellers, and, without
duplication, each of them, the due and punctual payment of any and all amounts
payable, or that become payable, from Serologicals to Sellers pursuant to the
Operative Documents and the performance of all covenants and agreements of
Serologicals under the Operative Documents (such amounts, covenants and
agreements being hereinafter referred to as the "Obligations").

         This Guaranty shall be enforceable without Sellers, or any of them,
having to proceed first against Serologicals before proceeding against
Guarantor, and shall be effective regardless of the solvency or insolvency of
Serologicals or Guarantor (except to the extent that the obligation of the
Guarantor is discharged in a bankruptcy proceeding), any reorganization, merger
or consolidation of Serologicals or Guarantor, or any change in the ownership,
composition, nature, personnel or location of Serologicals or Guarantor. In any
proceeding regarding this Guaranty, Guarantor shall be entitled to all defenses
available to Serologicals under the Operative Documents; provided, however, that
Guarantor shall not assert any such defense to the extent it has been determined
by final judgment of a court of competent jurisdiction that such defense is not
available to Serologicals. Guarantor's obligations under this Guaranty are
independent of those of Serologicals and those of any other person.

         This Guaranty shall be binding upon Guarantor and its successors and
assigns and shall inure to the benefit of Sellers and their respective
successors and assigns.

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         Guarantor shall pay to (in immediately available funds) and perform,
for the benefit of Sellers, when due, on demand of Sellers, all Obligations.
This Guaranty is a guaranty of payment and not of collectibility.

         Guarantor acknowledges that it is relying upon its own knowledge of and
is fully informed with respect to Serologicals' financial condition. Guarantor
assumes full responsibility for keeping fully informed of Serologicals'
financial condition and all other circumstances affecting Serologicals' ability
to perform the Obligations, and agrees that Sellers will have no duty to report
to Guarantor any information which Sellers receive about Serologicals' financial
condition or any circumstances bearing on Serologicals' ability to perform all
or any portion of the Obligations, regardless of whether Sellers have reason to
believe that any such facts materially increase the risk beyond that which
Guarantor intends to assume or has reason to believe that such facts are unknown
to Guarantor or has a reasonable opportunity to communicate such facts to
Guarantor.

         The Guarantor waives and agrees not to assert or take advantage of: (a)
any right to require Sellers to proceed against Serologicals, any other
guarantor or any other person or any security now or hereafter held by Sellers
or to pursue any other remedy whatsoever, including any such right or any other
right set forth in or arising out of Sections 2845, 2850, 2899 or 3433 of the
California Civil Code; (b) any defense based upon any legal disability of
Serologicals or any guarantor or other person, or any discharge or limitation of
the liability of Serologicals or any guarantor or other person to Sellers (or
any of them), or any restraint or stay applicable to actions against
Serologicals or any guarantor or other person, whether such disability,
discharge, limitation, restraint or stay is consensual, or arising by order of a
court or other governmental authority, or arising by operation of law or any
liquidation, reorganization, insolvency, receivership, bankruptcy, assignment
for the benefit of creditors or other debtor-relief proceeding, or from any
other cause, including any defense to the payment of interest, attorneys' fees
and costs, and other charges that otherwise would accrue or become payable in
respect to the Obligations after the commencement of any such proceeding; (c)
setoff, counterclaim, presentment, demand, protest, notice of protest, notice of
nonpayment, or other notice of any kind; (d) any defense based upon the
modification, renewal, extension or other alteration of any of the Obligations,
or of the documents executed in connection therewith; (e) any defense based upon
the negligence of Sellers (or any of them), including the failure to record an
interest under a deed of trust, the failure to perfect any security interest,
the failure to file a claim in any bankruptcy of Serologicals or any guarantor
or other person or in other administration of the Obligations; (f) any defense
based upon a statute of limitations to the fullest extent permitted by law and
any defense based upon any of the Sellers' delay in enforcing this Guaranty or
any other agreement; (g) all rights of subrogation, reimbursement, indemnity and
contribution, all rights to enforce any remedy that Sellers may have against
Serologicals or other person, until the Obligations have been paid and performed
in full, and any defense based upon the impairment of any subrogation,
reimbursement, indemnity or contribution rights that Guarantor might have,; (h)
any defense based upon the death, incapacity, lack of authority or termination
of existence of, or purported revocation or rescission of this Guaranty or any
of the Obligations by, any person, or the substitution of any party hereto or
thereto; (i) any defense based upon or related to Guarantor's lack of knowledge
as to Serologicals' financial condition; (j) any right to revoke this Guaranty
or obligations hereunder and all rights and benefits of Section 2815 of the
California

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Civil Code; (k) any right to designate the order of application of any sums or
property received by Sellers (or any of them), and in connection therewith
Guarantor agrees that any amounts received by any of Sellers from any source on
account of the Obligations may be applied by Sellers toward payment thereof in
such order as Sellers may from time to time elect, notwithstanding any contrary
designation by Serologicals, Guarantor or any other person; (l) any defense
based upon any action taken or omitted by Sellers (or any of them) in any
bankruptcy or other insolvency proceeding involving Serologicals or any other
person, including any election to have any of Sellers' claim(s) allowed as
secured, partially secured or unsecured, any extension of credit by any of
Sellers to Serologicals in any such proceeding, and the taking and holding by
Sellers of any security for any such extension of credit; and (m) any right or
defense that is or may become available to Guarantor by reason of California
Civil Code Sections 2787 to and including 2855, 2899 and 3433.

         The obligations of Guarantor under this Guaranty shall not be altered,
limited, stayed or affected by any proceeding, voluntary or involuntary,
involving the bankruptcy, insolvency, receivership, reorganization, liquidation,
or arrangement of Serologicals, or by any defense Serologicals may have by
reason of any order, decree, or decision of any court or administrative body
resulting from any such proceeding. Any stay of enforcement or of acceleration
of the time for payment of any of the Obligations as against Serologicals or any
other person shall have no effect upon Guarantor's liability under this Guaranty
or the time for payment by Guarantor hereunder.

         The liability of Guarantor hereunder shall continue in effect
notwithstanding any payment or performance of the Obligations by Serologicals or
any other person, such that, if any such payment or performance is avoided or
recovered from Sellers (or any of them) or Sellers (or any of them) are
otherwise required to restore or return any such payment or performance in
connection with the bankruptcy, insolvency or reorganization of Serologicals or
otherwise, Guarantor shall remain liable hereunder as though such payment or
performance had not occurred. Sellers shall be under no obligation to return or
deliver this Guaranty to Guarantor, notwithstanding the payment or performance
of the Obligations. If this Guaranty is nevertheless returned to Guarantor or is
otherwise released, then the provisions herein shall survive such return or
release, and the liability of Guarantor under this Guaranty shall survive such
return or release, and Guarantor shall remain liable under this Guaranty under
the circumstances provided herein notwithstanding such return or release.

         This Guaranty has been made and delivered in the State of California
and shall be governed by the laws of that State without reference to its
conflict of laws principles. Whenever possible each provision of this Guaranty
shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Guaranty shall be prohibited by or
be invalid under such law, such provision shall be ineffective to the extent of
such prohibition or invalidity, without invalidating the remainder of such
provision or the remaining provisions of this Guaranty.

         Any notice, request, instruction or other document to be given
hereunder to the Guarantor shall be in writing and delivered personally or sent
by registered or certified mail or by any express mail or overnight courier
service, postage or fees prepaid to:

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                  Serologicals Corporation
                  5655 Spalding Drive
                  Norcross, Georgia 30092
                  Attention: Jeffrey Linton

         with a copy to:

                  King & Spalding LLP
                  191 Peachtree Street
                  Atlanta, Georgia 30303-1763
                  Attention: Philip A. Theodore, Esq.

or at such other address as shall be specified by like notice.

         Any notice that is delivered personally in the manner provided herein
shall be deemed to have been duly given to Guarantor upon actual receipt by
Guarantor or its agent. Any notice that is addressed and mailed or sent by
courier in the manner herein provided shall be conclusively presumed to have
been duly given to Guarantor at the close of business, Atlanta time, on the
fourth Business Day after the day it is so placed in the mail or, if earlier,
the time of actual receipt. "Business Day" means any day except Saturday, Sunday
or any day on which banks are generally not open for business in the City of
Atlanta.

         Guarantor hereby irrevocably consents and agrees that, except as
provided in the next sentence, any action, suit or proceeding arising in
connection with any disagreement, dispute, controversy or claim arising out of
or relating to this Guaranty or any related document (for purposes of this
paragraph, a "Legal Dispute") shall be brought only to the exclusive
jurisdiction of the courts of the State of California or the federal courts
located in the State of California, County of San Diego; provided, however, that
no party shall be prevented from raising an objection to subject matter
jurisdiction in such forum. Guarantor agrees that, after a Legal Dispute is
before a court as specified in this paragraph and during the pendency of such
Legal Dispute before such court, all actions, suits or proceedings with respect
to such Legal Dispute or any other Legal Dispute, including, any counterclaim,
cross-claim or interpleader, shall be subject to the exclusive jurisdiction of
such court. Guarantor hereby waives, and agrees not to assert, as a defense in
any Legal Dispute, that it is not subject thereto or that such action, suit or
proceeding may not be brought or is not maintainable in such court (other than
as set forth above with respect to subject-matter jurisdiction) or that its
property is exempt or immune from execution, that the action, suit or proceeding
is brought in an inconvenient forum or that the venue of the action, suit or
proceeding is improper (other than as set forth above with respect to
subject-matter jurisdiction). Guarantor agrees that a final judgment in any
action, suit or proceeding described in this paragraph after the expiration of
any period permitted for appeal and subject to any stay during appeal shall be
conclusive and may be enforced in other jurisdictions by suit on the judgment or
in any other manner provided by applicable laws.

         Any provision of this Guaranty which is prohibited or unenforceable in
any jurisdiction will, as to such jurisdiction, be ineffective to the extent of
such prohibition or unenforceability

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without invalidating the remaining provisions of this Guaranty, and any such
prohibition or unenforceability in any jurisdiction will not invalidate or
render unenforceable such provision in any other jurisdiction. To the extent
permitted by law, Guarantor waives any provision of law which renders any such
provision prohibited or unenforceable in any respect.

         This Guaranty supersedes all negotiations, agreements and
understandings with respect to the subject matter of this Guaranty and
constitutes the entire agreement of the Guarantor with respect thereto.

         IN WITNESS WHEREOF, Guarantor has executed this Guaranty as of the 11th
day of February, 2003.

                                       SEROLOGICALS CORPORATION

                                       By: /s/ David A. Dodd
                                           President and Chief Executive Officer

                                       5<PAGE>
                                                                   EXHIBIT 10.25

                                                          [LOGO]

January 2, 1998

Keith Thompson
55 Caiyside Fairmilehead
Edinburgh,
EH10 7HW
UK

Dear Keith:

I am pleased to offer you ("you" or the "Executive") employment (the
"Employment") with Bioscot, Ltd. on behalf of Serologicals Corporation (the
"Corporation"), on the terms set forth herein (the "Offer"). This Offer extends
your present employment with Bioscot, Ltd. which commenced on May 1, 1985.

1. Position, Duties and Responsibilities.

    a. You shall serve as the Vice President, Diagnostic Operations,
responsible for the duties outlined in the attached Job Description. Your
primary location will be at Bioscot's Livingston facility, but you will be
required to visit the facilities of the Corporation in the U.S.A. and carry out
other duties outside of Scotland, as required.

    b. You will devote all your business time and attention to the business and
affairs of the Corporation consistent with your position with the Corporation.
Nothing herein, however, shall preclude you from engaging in charitable and
community affairs, or giving attention to your investments provided that such
activities do not interfere with the performance of your duties and
responsibilities enumerated herein. You will maintain Directorship on the
Bioscot, Ltd. board and carry out the duties of Managing Director where
required for no additional compensation.

    c. Except as otherwise specifically stated herein, you shall be subject to
all of the requirements and provisions described in the employee handbook, as
it may be amended from time to time.

    d. This Employment Agreement shall commence on January 2, 1998 (the
"Effective Date") and continue for successive one (1) year periods, unless
otherwise terminated pursuant to the provisions hereof.

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2. Compensation and Related Matters.

    a. Base Salary.  You shall be paid a base salary (the "Base Salary") equal
to $125,000 per year. The Base Salary shall be payable to you by Bioscot, Ltd.
in the manner and on the date(s) on which the Corporation pays its other
executives, but in no event less frequently than monthly. The salary will be
translated into UK currency at the prevailing rate of exchange or by a
mechanism that will be agreed from time to time.

    b. Incentive Compensation.  You shall be eligible to participate in such
bonus and incentive compensation plans of the Corporation in which other
officers of the Corporation are generally eligible to participate, as the Board
or a Committee thereof shall determine from time to time in its sole discretion,
subject to and in accordance with the terms and provisions of such plans.

    c. Employee Benefit Programs.  You shall be eligible to receive fringe
benefits now provided or may hereinafter be provided by the Corporation to its
executives. You will be eligible for all benefits normally provided for
employees of Bioscot and Bioscot rules will apply.

    d. Reimbursement of Expenses.  It is contemplated that in connection with
your Employment hereunder, you may be required to incur business, entertainment
and travel expenses. The Corporation agrees to promptly reimburse you in full
for all reasonable out-of-pocket business, entertainment and other related
expenses (including all expenses of travel and living expenses while away from
home on business or at the request of, and in service of, the Corporation)
incurred or expended by you incident to the performance of your duties
hereunder; provided that you properly account for such expenses in accordance
with the policies and procedures established by the Board and applicable to the
executives of the Corporation.

    e. Paid Time Off.  You shall be entitled, in each calendar year of your
Employment, to the number of paid vacation days determined by the Corporation
from time-to-time to be appropriate for its executives, but in no event less
than five (5) weeks in any such year during your Employment (pro-rated, as
necessary for partial calendar years during your Employment). You may take your
allotted vacation days at such times as are mutually convenient for the
Corporation and you, consistent with the Corporation's vacation policy in
effect with respect to its executives. You shall also be entitled to all nine
(9) statutory or public holidays recognized by Bioscot, Ltd.

3. Termination by the Company. Notwithstanding the foregoing, the Corporation
may terminate your employment at any time. In the event of termination resulting
from the elimination of your position, you shall be entitled to continue to
receive your Base Salary for a nine (9) month period from the date of
termination. Under no other termination circumstances will you be eligible for
any form of salary continuation.

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<PAGE>
4.  Nondisclosure.  You acknowledge and agree that during your employment by the
Corporation hereunder, and during your prior employment with Bioscot Ltd., you
will come to have knowledge and information with respect to trade secrets or
confidential or secret plans, projects, materials, business methods,
operations, techniques, customers, employees, financial conditions, policies
and accounts of the Corporation with respect to the business of the
Corporation, including, but not limited to, the identity of donors and donor
lists of the Corporation, its successors or assigns or any of its affiliates
("Confidential Information"). You agree that you will not at any time divulge,
furnish or make accessible to anyone (other than in the regular course of your
performance of services for the benefit of the Corporation, its successors or
assigns) any Confidential Information of the Corporation. Notwithstanding the
foregoing, Confidential Information shall not include any information which (i)
is known generally to the public (other than as a result of unauthorized
disclosure by you), (ii) was available to you on a nonconfidential basis prior
to its disclosure to you by the Corporation or (iii) is required to be
disclosed pursuant to the valid order of a governmental agency or a judicial
court of competent jurisdiction, in which case you shall give prompt written
notice to the Corporation of such requirement so that the Corporation may take
such action as it deems appropriate.

The Corporation may call upon you at any time to take out patents on work
carried out by you during your appointment and to assign such patents to the
corporation or a nominee of the corporation.

5.  Non-Compete and Non-Solicitation.  As a material inducement to the
Corporation to enter into this letter, you agree that at all times during your
Employment and for a period of twelve (12) months after the termination of your
Employment, you will not, in any way, directly and indirectly, solicit, divert,
or take away or attempt to solicit, divert, or take away customers, the
business, or any of the donors of the Corporation that dealt with the
Corporation in any capacity through its donor center or laboratory operations
during your Employment.

You agree that during your Employment and for a period of nine (9) months after
the termination for any reason of your Employment, you will not in a geographic
area in which the Corporation was conducting business during the term of your
Employment or at the date of termination thereof, directly, or indirectly
through any means, including a business entity in which you have an ownership
interest, request or induce any other employee of the Corporation or its
affiliates or any donor to the Corporation or its affiliates to terminate their
relationship with the Corporation or its affiliates and enter into an
employment or consulting relationship with another business entity engaged in a
business similar to the Corporation's.

6.  Miscellaneous.

         a.  Governing Law.  This letter is to be governed by and interpreted
in accordance with the laws of Scotland.

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         b.  No Attorney Provided.  The Corporation advises you that it is not
providing legal advice in connection with your acceptance and execution hereof
and that, if you so elect, you should consult with an attorney prior to such
execution.

         c.  Affiliate.  References to the "Corporation" hereunder shall
include "affiliates" thereof, as such term is defined in Rule 405 under the US
Securities Act of 1933, as amended. The Corporation shall have the right to
designate as your employer hereunder Serologicals, Inc., Seramed, Inc., any
affiliate of which the Executive shall have significant operating or managerial
responsibility or any other affiliate to which the Executive agrees; provided
that in the event of such designation, the Corporation shall remain responsible
for its obligations hereunder in the event that any such designee fails to
perform such obligation.

         d.  Severability.  If any provision of this Agreement shall be
determined to be invalid, illegal or unenforceable in whole or in part, all
other provisions hereof shall remain in full force and effect to the fullest
extent permitted by law.

Please indicate your acceptance of this Employment Agreement by signing in the
space provided below and returning to me no later than May 21, 1998.

                                        Very truly yours,

                                        SEROLOGICALS CORPORATION

                                        By: /s/ Harold J. Tenoso, Ph.D.
                                            ----------------------------------
                                                Harold J. Tenoso, Ph.D.
                                        Title: President/CEO Serologicals
                                               Corporation
                                               Director, Bioscot, Ltd.

ACKNOWLEDGED AND AGREED
this 6th day of May 1998.

/s/ Keith J. Thompson
--------------------------------------
    Keith J. Thompson

KJTCONTRACT                            4

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