Document:

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                                                                    Exhibit 10.1

                              AMENDED AND RESTATED
                                 PROMISSORY NOTE

$155,000                                            Effective as of May 30, 2000

         For value received, the undersigned, Marc Douglas, ("Borrower"),
promises to pay to the order of Thrift Management, Inc. ("Lender"), the
principal sum of One Hundred, Fifty-Five Thousand ($155,000) or so much thereof
as may be advanced from time to time by the Lender in lawful money of the United
States of America, together with interest accruing thereon from the date hereof
at the rate hereinafter provided, calculated on the daily outstanding principal
balances from time to time based on a 360-day year.

         This Amended and Restated Note shall bear interest at a rate of 8% per
annum. Payments of accrued interest on the principal balance outstanding from
time to time on this Amended and Restated Note shall commence on the 1st day of
July, 2000, and on the same day of each month thereafter. The outstanding
principal balance of this Amended and Restated Note, and all accrued but unpaid
interest thereon, shall be payable on or before December 31, 2001. Borrower
hereby agrees that if not paid as provided herein, the principal balance and any
accrued but unpaid interest thereon may be offset against and deducted from any
amounts due to Borrower from Lender.

         This Amended and Restated Note is a restatement of and substitution of
that certain Promissory Note effective as of January 1, 1999, which Note was
executed by Borrower in favor of Lender.

         So long as no default exists under this Amended and Restated Note,
Borrower shall have the right to prepay the unpaid principal balance evidenced
by this Amended and Restated Note in whole or in part without premium or penalty
but with accrued interest to the date of such prepayment on any amount prepaid,
and to borrow and reborrow such amounts up to the aggregate principal amount of
this Note.

         All payments received hereunder shall be applied first to the payment
of any expenses or charges payable hereunder, then to interest due and payable,
with the balance applied to principal, or in such other order as Lender shall
determine at its option.

         Notwithstanding any provision of this Amended and Restated Note to the
contrary, the parties intend that no provision of this Amended and Restated Note
be interpreted, construed, applied or enforced so as to permit or require the
payment or collection of interest in excess of the highest rate of interest
permitted to be paid or collected by the laws of the State of Florida (or
federal law, in the event federal law preempts Florida law or is otherwise
applicable), with respect to this transaction ("Maximum Permitted Rate"). If the
rate of interest charged by Lender under the provisions of this Amended and
Restated Note exceeds the Maximum Permitted Rate, then Lender and any holders of
this Amended and Restated Note, and Borrower and any endorsers and guarantors,
do hereby agree that the provisions of this Amended and Restated Note
automatically shall be deemed reformed NUNC PRO TUNC so as to require payment
only of interest at the Maximum Permitted Rate; and if interest payments in
excess of such Maximum Permitted Rate have been received, the amount of such
excess shall be deemed credited NUNC PRO TUNC in reduction of the
then-outstanding principal amount of this obligation,

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together with interest at such Maximum Permitted Rate. In connection with all
calculations to determine the Maximum Permitted Rate, the parties intend: first,
that all charges be excluded to the extent they are properly excludable under
the usury laws of the State of Florida, as they from time to time are determined
to apply to this obligation; and, second, that all charges that may be "spread"
in the manner provided by Section 687.03(3), Florida Statutes, or any similar
successor law.

         Any payment not made when due shall constitute a default. If default be
made in the payment of any installment under this Amended and Restated Note, the
entire principal sum and accrued interest shall become due and payable without
notice at the option of the Lender. Failure to exercise this option shall not
constitute a waiver of the right to exercise the same at any other time. Upon
such default, the unpaid principal balance of this Amended and Restated Note,
and accrued and unpaid interest, if any, shall bear interest at 18% from the
date of default until the default is corrected. Lender's failure to exercise
this right with respect to any default shall not constitute a waiver of this
right as to any subsequent default. All parties liable for the payment of this
Amended and Restated Note agree to pay the Lender hereof reasonable attorneys'
fees for the services and expenses of counsel employed after default to collect
this Amended and Restated Note (including any appeals relating to such
enforcement proceedings), whether or not suit be brought.

         The remedies of Lender as provided herein shall be cumulative and
concurrent, and may be pursued singly, successively or together, at the sole
discretion of Lender, and may be exercised as often as occasion therefor shall
arise. No act of omission or commission of Lender, including specifically any
failure to exercise any right, remedy or recourse, shall be effective as a
waiver thereof unless it is set forth in a written document executed by Lender
and then only to the extent specifically recited therein. A waiver or release
with reference to one event shall not be construed as continuing, as a bar to,
or as a waiver or release of, any subsequent right, remedy or recourse as to any
subsequent event.

         Borrower and all sureties, endorsers and guarantors of this Amended and
Restated Note hereby: (a) waive demand, presentment for payment, notice of
nonpayment, protest, notice of protest and all other notice, filing of suit and
diligence in collecting this Amended and Restated Note, in enforcing any of its
rights; (b) agree to any addition or release of any party or person primarily or
secondarily liable hereon; (c) agree that Lender shall not be required first to
institute any suit, or to exhaust his, their or its remedies against Borrower or
any other person or party to become liable hereunder in order to enforce payment
of this Amended and Restated Note; (d) consent to any extension, rearrangement,
renewal or postponement of time of payment of this Amended and Restated Note and
to any other indulgence with respect hereto without notice, consent or
consideration to any of the foregoing; (e) agree to the right to set off against
any deposits, funds or monies owing; and (f) agree that, notwithstanding the
occurrence of any of the foregoing (except the express written release of Lender
of any such person), they shall be and remain jointly and severally, directly
and primarily, liable for all sums due under this Amended and Restated Note.

         BORROWER KNOWINGLY, INTENTIONALLY AND VOLUNTARILY WAIVES ANY RIGHT
BORROWER HAS TO A TRIAL BY JURY IN CONNECTION WITH ANY MATTER DIRECTLY OR
INDIRECTLY RELATING TO THIS AMENDED AND RESTATED NOTE. BORROWER ACKNOWLEDGES
THAT NEITHER LENDER NOR

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ANY PERSON ACTING ON BEHALF OF LENDER HAS MADE ANY REPRESENTATIONS OF FACT TO
INDUCE THIS WAIVER OF TRIAL BY JURY OR IN ANY WAY MODIFY OR NULLIFY ITS EFFECT.

         As used herein, the words "Borrower" and "Lender" shall be deemed to
include Borrower and Lender as defined herein and their respective heirs,
personal representatives, successors and assigns.

                                                                /s/ Marc Douglas
                                                                ----------------
                                                                Marc Douglas

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                                                                   EXHIBIT 10.28

                                                              September 28, 2000

Mr. Jeffrey D. Linton
414 Hickory Fairway Court
Woodstock, GA 30188

Dear Mr. Linton:

I am pleased on behalf of Serologicals Corporation (the "Corporation") to offer
you ("you" or the "Executive") employment (the "Employment") on the terms set
forth herein (the "Offer").

1. Position, Duties and Responsibilities.

         a. You shall serve as the Vice President, Corporate Business
Development, Legal and Public Affairs responsible for the duties outlined in the
attached Job Description.

         b. You will devote all your business time and attention to the business
and affairs of the Corporation and its subsidiaries consistent with your
position. 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.

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

         d. Following any termination of the your employment, upon the request
of the Corporation, you shall reasonably cooperate with the Corporation in all
matters relating to the winding up of pending work on behalf of the Corporation
and the orderly transfer of work to other employees of the Corporation. You
shall also reasonably cooperate in the defense of any action brought by any
third party against the Corporation that relates in any way to your acts or
omissions while employed by the Corporation. The Corporation shall reimburse you
for your reasonable out-of-pocket costs, if any, as permitted by law, incurred
in cooperating with the Corporation.

2. Term.

         Your Employment shall commence hereunder effective on or about October
16, 2000 (the "Effective Date") and continue for successive one (1) year
periods, unless otherwise terminated pursuant to the provisions hereof.

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                                                               Jeffrey D. Linton
                                                              September 28, 2000

3. Compensation and Related Matters.

         a. Base Salary. You shall be paid a base salary (the "Base Salary")
equal to one hundred and eighty thousand dollars ($180,000) per year. The Base
Salary shall be payable to you in the manner and on the date(s) on which the
Corporation pays its other executives, but in no event less frequently than
monthly.

         b. Incentive Compensation. You shall be entitled to an annual bonus
target of forty percent (40%) of the Base Salary in accordance with and subject
to your achievement of the Bonus Milestone Requirements, to be developed and
mutually agreed upon by you and the Chief Executive Officer of the Corporation
(the "C.E.O."). You shall also be eligible to participate in such bonus and
incentive compensation plans of the Corporation, if any, in which other
executives of the Corporation are generally eligible to participate, as the
Corporation's Board of Directors ("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. It is understood that should you
commence Employment by October 16, you will be eligible for a pro-rated bonus
for the year 2000.

         c. Employee Benefit Programs. You shall be eligible to participate in
the employee benefit programs (subject to their respective terms) now provided
or as may hereinafter be provided by the Corporation to its executives. Current
benefit programs include:

         -        Group Health Insurance

         -        Corporation Paid Life Insurance (two times your annual salary)

         -        Supplemental and Dependent Life Insurance

         -        Serologicals, Inc.'s Employees' Retirement Plan - 401(k)

         -        Short-term Disability Insurance

         -        Long-term Disability Insurance

         -        Flexible Spending Account (Medical and Dependent Care)

         -        Serologicals Corporation's Employee Stock Purchase Plan

         d. Stock Options. You are hereby granted a non-qualified employee stock
option under the Corporation's Second Amended and Restated 1994 Omnibus
Incentive Plan (the "Omnibus Incentive Plan") (subject to final approval by the
Compensation Committee of the Board) to purchase seventy-five thousand (75,000)
shares of the Corporation's $.01 par value common stock at an initial exercise
price equal to the fair market value of such stock on the Effective Date
("Options"). The Options shall have a term of six (6) years and, so long as you
are then employed by the Corporation, the right to exercise the Options shall
vest and be fully exercisable at the rate of twenty-five percent (25%) per year
commencing on the first anniversary of the Effective Date. Such Options shall be
issued pursuant to a stock option

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                                                               Jeffrey D. Linton
                                                              September 28, 2000

agreement entered into by you and the Corporation and shall be subject to all
the other terms and conditions contained in the Omnibus Incentive Plan, the
provisions of which shall be determined in the sole discretion of the Board or a
committee thereof.

         e. 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.

         f. 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 four (4) 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 forty (40) hours
of family/medical paid time off and forty (40) hours of sick leave per calendar
year (pro-rated, as necessary, for partial calendar years during your
Employment). You shall also be entitled to all paid holidays given by the
Corporation to its executives.

4. Termination.

         a. Disability of the Executive. In the event of your incapacity or
inability to perform your services as contemplated herein for an aggregate of
ninety (90) days during any twelve (12) month period due to the fact that your
physical or mental health shall have become impaired so as to make it impossible
in the judgment of the Corporation for you to perform the duties and
responsibilities contemplated for you hereunder, the Corporation shall have the
right to declare, upon two (2) weeks prior written notice rendered to you, a
disability termination, whereupon you shall receive (if you are entitled
thereto) the short and/or long-term disability benefits provided by the
Corporation. In the event you have commenced receiving benefits under the
Corporation's disability plans, until termination of your employment under this
Section 4(a), the Corporation shall not be obligated to pay to you with regard
to Base Salary an amount greater than the difference between your Base Salary
then in effect and any such disability benefits you are then receiving.

         b. Death of the Executive. In the event you die during your Employment
hereunder, your Employment shall automatically terminate without notice on the
date of your death, except that your estate shall receive the death benefits, if
any, provided by the Corporation.

         c. Termination by the Corporation for Cause. Nothing herein shall
prevent the Corporation from terminating your Employment for Cause (as defined
below). From and after the date of such termination, you shall no longer be
entitled to receive the Base Salary or any other compensation which would have
otherwise been due and all Options shall terminate immediately. Any rights and
benefits that you may have in respect to any other compensation or any employee
benefit plans or programs of the Corporation shall be determined in accordance
with the terms of such other compensation arrangements, plans or programs, and
in any event, you shall have no rights or benefits under any arrangement, plan
or program

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                                                               Jeffrey D. Linton
                                                              September 28, 2000

unless such arrangement, plan or program is in writing and you are specified as
a participant therein. The term "for Cause", as used herein, shall mean (i) your
willful misconduct, gross negligence or dishonesty in the performance of your
duties on behalf of the Corporation, (ii) your willful neglect, failure or
refusal to carry out any reasonable request of the Board or President/C.E.O. of
the Corporation consistent with your obligations contemplated hereunder, (iii)
the material breach of any provision of this letter by you or (iv) the entering
of a plea of guilty or nolo contendere to, or your conviction of, a felony or
other crime involving moral turpitude, dishonesty, theft or unethical business
conduct. Termination of employment pursuant to this Section 4(c) shall be made
to the Executive by, and be effective upon, written notice from the
President/C.E.O. or the Board.

         d. All Other Terminations by the Company. Notwithstanding the
foregoing, the Corporation may terminate your employment at any time. If your
employment is terminated for any reason other than "for Cause", death or
disability, you shall continue to receive your current Base Salary and benefits
for a period of twelve (12) months from the date of such termination.

5. Nondisclosure.

         You acknowledge and agree that, during your employment by the
Corporation hereunder, you have or 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,
donors, products, processes, financial conditions, policies and accounts of the
Corporation with respect to the business of the Corporation ("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. 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), (ii) was
available to you on a non-confidential 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.

6. 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
twenty-four (24) months after the termination of your Employment, you will not
(i) act in a capacity similar to that in which you shall have served in the
Corporation (including as vice president of corporate business development,
legal and/or public affairs) for any Competing Business or serve in a capacity
in any such Competing Business that would entail your developing or implementing
an acquisition strategy, establishing an internal legal function and/or acting
as a liaison to external legal resources, or managing a corporate
communications, public relations or investor relations function for a Competing
Business, or (ii) in any way, directly or indirectly, compete with the business
of the Corporation, solicit, divert, or take away or attempt to solicit, divert,
or take away customers of, the business of, or any of the donors of, the
Corporation that dealt with the Corporation during your Employment. Competing
Business means another business engaged in the business(es) engaged in by the
Corporation at any time within one year or at the time of your termination and
the business(es) specifically acknowledged in a separate writing by you and the
Corporation as conducted by the Corporation.

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                                                               Jeffrey D. Linton
                                                              September 28, 2000

You agree that during your Employment and for a period of twenty-four (24)
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 a
similar relationship with another business entity engaged in a business similar
to the Corporation's.

7. Executive Creation and Ideas

         a. You will maintain current and adequate written records on the
development of, and disclose to the Corporation all Creations (as herein
defined). "Creations" shall mean all ideas, potential marketing and sales
relationships, inventions, copyrightable expression, research, plans for
products or services, marketing plans, reports, strategies, processes, computer
software (including, without limitation, source code), computer programs,
original works of authorship, characters, know-how, trade secrets, information,
data, developments, discoveries, improvements, modifications, technology,
algorithms, database schema, designs, and drawings, whether or not subject to
patent or copyright protection, made, conceived, expressed, developed, or
actually or constructively reduced to practice by you solely or jointly with
others during your employment with the Corporation, which refer to, are
suggested by, or result from any work which you may perform during your
employment, or from any information obtained from the Corporation or any
affiliate of the Corporation. 'Creations,' however, shall not include the
general business planning concepts, strategies or processes, including, but not
limited to, those utilized by you in any prior employment.

         b. The Creations shall be the exclusive property of the Corporation,
and you acknowledge that all of said Creations shall be considered as "work made
for hire" belonging to the Corporation. To the extent that any such Creations,
under applicable law, may not be considered work made for hire by you for the
Corporation, you hereby agree to assign and, upon its creation, automatically
and irrevocably assign to the Corporation, without any further consideration,
all right, title and interest in and to such materials, including, without
limitation, any copyright, other intellectual property rights, moral rights, all
contract and licensing rights, and all claims and causes of action of any kind
with respect to such materials. The Corporation shall have the exclusive right
to use the Creations, whether original or derivative, for all purposes without
additional compensation to you. At the Corporation's expense, you will
reasonably assist the Corporation in every reasonably proper way to perfect the
Corporation's rights in the Creations and to protect the Creations throughout
the world, including, without limitation, executing in favor of the Corporation
or any designee(s) of the Corporation patent, copyright, and other applications
and assignments relating to the Creations.

         c. Should the Corporation be unable to secure your signature on any
document necessary to apply for, prosecute, obtain, or enforce any patent,
copyright, or other right or protection relating to any Creation, whether due to
your mental or physical incapacity or any other cause, you hereby irrevocably
designate and appoint the Corporation and each of its duly authorized officers
and agents as your agent and attorney in fact, to act for and in your behalf and
stead and to execute and file any such document, and to do all other lawfully
permitted acts to further the prosecution, issuance, and enforcement of patents,
copyrights, or other rights or protections with the same force and effect as if
executed and delivered by you.

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                                                               Jeffrey D. Linton
                                                              September 28, 2000

         d. Because of the difficulty of establishing when any idea, process or
invention is first conceived or developed by you, or whether it results from
access to Confidential Information or the Corporation's equipment, supplies,
facilities, and data (collectively, "Corporation Information"), you agree that
any idea, invention, research, plan for products or services, marketing plan,
computer software (including, without limitation, source code), computer
program, original work of authorship, character, know-how, trade secret,
information, data, developments, discoveries, technology, algorithm, design,
patent or copyright, or any improvement, rights, or claims (an "Idea") related
to the foregoing, which refer to, are suggested by, or result from any work
which you performed during your employment with the Corporation or from any
Corporation Information, shall be presumed to be a Creation if it is conceived,
developed, used, sold, exploited or reduced to practice by you or with your aid
within one (1) year after termination of employment. This paragraph, however,
shall not apply to anything that is specifically excepted from the definition of
"Creations" in the last sentence of Section 7(a). You can rebut the above
presumption if you prove that the idea, process or invention (a) was first
conceived or developed after termination of employment, (b) was conceived or
developed entirely on your own time without using any Corporation Information,
and (c) did not result from any work performed by you for the Corporation.

8. Injunctive Relief/Survival.

         You agree that any breach of this Section 5, 6 or 7 will cause
irreparable damage to the Corporation and that, in the event of such breach, the
Corporation will have, in addition to any and all remedies of law, including
rights which the Corporation may have to damages, the right to equitable relief
including, as appropriate, all injunctive relief or specific performance or
other equitable relief. You understand and agree that the rights and obligations
set forth in Sections 5 through 10 of this Agreement shall survive the
termination or expiration of this Agreement.

9. Corporation Resources.

         You may not use any of the Corporation's equipment for personal
purposes without written permission from the Corporation. You may not give
access to the Corporation's offices or files to any person not in the employ of
the Corporation without written permission of the Corporation.

10. Miscellaneous.

         a. General. This Agreement supersedes and replaces any existing
agreement between the Executive and the Corporation relating generally to the
same subject matter, and may be modified only in a writing signed by the parties
hereto. Failure to enforce any provision of the Agreement shall not constitute a
waiver of any term herein. The Executive agrees that he will not assign,
transfer, or otherwise dispose of, whether voluntarily or involuntarily, or by
operation of law, any rights or obligations under this Agreement. Any purported
assignment, transfer, or disposition shall be null and void. Nothing in this
Agreement shall prevent the consolidation of the Corporation with, or its merger
into, any other corporation, or the sale by the Corporation of all or
substantially all of its properties or assets, or the assignment by the
Corporation of this Agreement and the performance of its obligations hereunder.
Subject to the foregoing, this Agreement shall be binding upon and shall inure
to the benefit of the parties and their respective heirs, legal representatives,
successors, and permitted assigns, and shall not benefit any person or entity
other than those enumerated above.

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                                                               Jeffrey D. Linton
                                                              September 28, 2000

         b. Governing Law. This letter is to be governed by and interpreted in
accordance with the laws of the State of Georgia applicable to agreements made
and to be performed within that State except as provided herein.

         c. No Attorney Provided. The Corporation advises you that it is not
providing legal advice in connection with your acceptance and execution hereof.
You acknowledge (a) that you have consulted with or have had the opportunity to
consult with independent counsel of your own choice concerning this Agreement
and have been advised to do so by the Corporation, and (b) that you have read
and understand the Agreement, are fully aware of its legal effect, and have
entered into it freely based on your own judgment.

         d. Affiliate. References to the "Corporation" hereunder shall include
"affiliates" thereof, as such term is defined in Rule 405 under the Securities
Act of 1933, as amended. The Corporation shall have the right to designate as
your employer hereunder any affiliate of which the Executive shall have
significant operating or managerial responsibility or any other affiliate to
which the Executive agrees.

         e. Severability. If any provision of this letter 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 Offer by signing in the space
provided below.

                                              Very truly yours,

                                              SEROLOGICALS CORPORATION

                                              By: /s/ David A. Dodd
                                                 -------------------------------
                                                  David A. Dodd
                                                  President and C.E.O.

         ACKNOWLEDGED AND AGREED this 29th day of September, 2000

         /s/ Jeffrey D. Linton
         -------------------------------
         Jeffrey D. Linton

                                       7

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