Document:

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                                   EXHIBIT 4.2

                      AMENDMENT TO RETAINER AGREEMENT WITH

                                 HORWITZ & BEAM,

                             DATED JANUARY 24, 2000

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                                 LAW OFFICES OF
                                 HORWITZ & BEAM
                          TWO VENTURE PLAZA, SUITE 350
                            IRVINE, CALIFORNIA 92618
                                 (949) 453-0300
                                 (310) 842-8574
                               FAX: (949) 453-9416

Gregory B. Beam, Esq.                                 Patti L.W. McGlasson, Esq.
Lawrence W. Horwitz, Esq.                              K. William Pergande, Esq.
Lynne Bolduc, Esq.                                        John Y. Igarashi, Esq.
Lawrence M. Cron, Esq.                                 Christopher T. Jain, Esq.
Ralph R. Loyd, Esq.                                        Matteo G. Daste, Esq.

                                                             Mark S. Dodge, Esq.
 E-mail: lbolduc@h-blaw.com                                           of Counsel

                                January 24, 2000
Mr. Tony Shahbaz
I/OMagic Corporation
6B Autry
Irvine, CA  92618

         RE:  LEGAL REPRESENTATION

Dear Mr. Shahbaz:

         On September 28, 1993, the Company entered into a Retainer Agreement
(the "Retainer Agreement") with Horwitz & Beam pursuant to which Horwitz & Beam
agreed to provide legal services to the Company commencing as of the date of the
agreement. The term of the Retainer Agreement shall be until either party
terminates the agreement. Under the terms of the Retainer Agreement, Horwitz &
Beam is to represent, advise, and counsel the Company concerning general
business and corporate matters.

         The Company wishes to continue the engagement of Horwitz &Beam in a
proposed arbitration proceeding by the Company (the "Matter") and wishes to pay
for some of the services rendered in the Matter with Shares of Common Stock with
registration rights on Form S-8. Therefore, this Agreement shall amend our
Retainer Agreement to provide for the registration of Form S-8 of 40,000 Shares
payable to Horwitz &Beam under the same terms as contained in the Retainer
Agreement.

COMPENSATION

         In connection with the Retainer Agreement, the Company has agreed to
register on Form S-8 40,000 shares of Common Stock of the Company over the term
of the Retainer Agreement and which are not being administered by either the
Board of Directors of the Company or any committee of the Board of Directors
organized for that purpose. The Company agrees to compensate Horwitz & Beam for
services rendered in connection with the Matter in accordance with the following
terms:

         $100 per hour payable in the form of stock issuable at $2.00 per share,
up to a maximum of 40,000 Share with Form S-8 registration rights ("Compensation
Shares"). All Compensation Shares shall have no lock-up period and Horwitz &
Beam shall have the right to immediately trade such Compensation Shares on the
public securities markets.

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                                 HORWITZ & BEAM
January 24, 2000
Page 2

RESTRICTIONS UNDER SECURITIES LAWS

         The sale of any shares of Common Stock must be made in compliance with
federal and state securities laws. Officers, directors and 10% or greater
stockholders of the Company, as well as certain other persons or parties who may
be deemed to be "affiliates" of the Company under the Federal Securities Laws,
should be aware that resales by affiliates can only be made pursuant to an
effective Registration Statement, Rule 144 or any other applicable exemption.
Officers, directors and 10% and greater stockholders are also subject to the
"short swing" profit rule of Section 16(b) of the Securities Exchange Act of
1934. Section 16(b) of the Exchange Act generally provides that if an officer,
director or 10% and greater stockholder sold any Common Stock of the Company
acquired pursuant to the exercise of a stock option or warrant, he would
generally be required to pay to the Company and "profits" resulting from the
sale of the stock and receipt of the stock option. Section 16(b) exempts all
option exercises from being treated as purchases and, instead, treats an option
grant as a purchase of the underlying security, which grant/purchase may be
matched with any sale of the underlying security within six months of the date
of grant.

         If this letter correctly sets forth your understanding and agreement
with respect to the matters mentioned above, please execute and return one copy
of this letter.

                                       Very truly yours,

                                       HORWITZ & BEAM

                                       /s/  Lawrence W. Horwitz
                                       ---------------------------
                                       Lawrence W. Horwitz

The undersigned hereby confirms and agrees that this letter, executed and
effective this 24th day of January, 2000, sets forth my understanding and
agreement.

I/OMAGIC CORPORATION

By: /s/  Tony Shahbaz
    --------------------------
    Tony Shahbaz
Title: President<PAGE>

                                 PROMISSORY NOTE

December 31, 1998                Daphne, Alabama
$290,448.17

Communitronics of America, Inc., referred to herein as "MAKER", agrees to pay
to the order of David R. Pressler, referred to herein as "HOLDER", or order,
the sum of $290,448.17, (two hundred eighty thousand two hundred fourteen &
17/100 Dollars), at 27955 Highway 98, Suite WWX, Daphne, Alabama, with interest
thereon at rate of 6.25% per annum, simple interest.

Said note shall be in due, unless earlier accelerated, in 59 installments
beginning January 31, 1999, payable every 30 days, in the amount of $1,608.72,
(one thousand six hundred eight & 72/100 Dollars) and one final installment on
December 31, 2003 of $285,317.93 (two hundred eighty-five thousand three hundred
seventeen & 93/100 Dollars). All payments received shall be credited first to
interest and then to principal. Should MAKER fail to pay any installment when
due, then HOLDER shall have the option to accelerate the payment of the full
principal sum and accrued interest payable. HOLDER shall have the right for
commercially reasonable causes, including but not limited to, the institution
of litigation, the filing of tax liens, or any other objective sign of
incapacity of the MAKER to pay the principal or interest due, to accelerate the
payment of the full principal sum and accrued interest payable.

This note is payable in U.S. Dollars. At any time the maximum rate of interest
applicable to this transaction shall not exceed the legal maximum rate of
interest for a note of this type. Any sums paid in excess of any lawful
limitation shall be applied to principal.

After default herein, this note will bear interest at the highest legal rate for
this type of note until paid in full. Upon any default, MAKER agrees to pay a
reasonable attorney's fee for any and all services of an attorney, whether in or
out of court, and for appeal and post-judgment collection legal services.

Dated:   December 31, 1998

/s/ David R. Pressler
---------------------------------------------------------
David R. Pressler, President and Chief Executive Officer
Communitronics of America, Inc.<PAGE>

                                                                     Exhibit 4.1

                              AMENDED AND RESTATED
                          REGISTRATION RIGHTS AGREEMENT

      THIS REGISTRATION RIGHTS AGREEMENT (the "Agreement") is made as of October
11, 1999, by and among Regeneration Technologies, Inc., a Florida corporation
(the "Company"), the investors set forth on Exhibit A to the Purchase Agreement
(as defined below) (the "Class C Investors"), the investors listed on Exhibit A
hereto (the "Class B Investors"), and the investors listed on Exhibit B hereto
(the "Class A Investors"). All parties to this Agreement shall be referred to
herein collectively as the "Parties." The Class A Investors, the Class B
Investors and the Class C Investors shall be referred to herein individually as
an "Investor" and collectively as the "Investors."

      WHEREAS, the Class A Investors own in the aggregate 1,777,348 outstanding
shares of the Class A Convertible Preferred Stock of the Company, par value
$0.001 per share (the "Class A Preferred");

      WHEREAS, the Class B Investors own in the aggregate 748,152 outstanding
shares of the Class B Convertible Preferred Stock of the Company, par value
$0.001 per share (the "Class B Preferred");

      WHEREAS, the Company and the Class C Investors are parties to that certain
convertible Class C Preferred Stock and Warrant Purchase Agreement of even date
herewith (the "Purchase Agreement"), pursuant to which the Class C Investors are
purchasing an aggregate of 368,990 shares of Class C Convertible Preferred Stock
of the Company, $0.001 par value per share (the "Class C Preferred"); and

      WHEREAS, as a condition to and to effect the transfer of assets to the
Company and the sale of the Class C Preferred, it is in the best interests of
the Company to grant to the Investors certain registration rights.

      NOW, THEREFORE, in consideration of the premises and mutual covenants
contained herein, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Parties agree as follows:

                                    ARTICLE I
                               REGISTRATION RIGHTS

            1.1 Certain Definitions. As used in this Article 1 and elsewhere in
this Agreement, the following terms shall have the following respective
meanings:

                  "Class A Registrable Shares" means (i) the shares of Common
Stock issued or issuable upon conversion of the Class A Preferred; (ii) any
shares of Common Stock of

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the Company acquired by the Class A Investors pursuant to Section 2 of that
certain Stockholders' Agreement by and among the Parties and of even date
herewith (the "Stockholders' Agreement"); and (iii) any other shares of Common
Stock of the Company issued in respect of such shares described in clauses (i)
and (ii) above (because of stock splits, stock dividends, reclassifications,
recapitalizations, or similar events); provided, however, that shares of Common
Stock which are Class A Registrable Shares shall cease to be Class A Registrable
Shares upon any sale pursuant to a Registration Statement, Section 4(1) of the
Securities Act or Rule 144 under the Securities Act. Wherever reference is made
in this Agreement to a request or consent of holders of a certain percentage of
Class A Registrable Shares, the determination of such percentage shall include
shares of Common Stock issuable upon conversion of the Class A Preferred even if
such conversion has not yet been effected.

                  "Class B Registrable Shares" means (i) the shares of Common
Stock issued or issuable upon conversion of the Class B Preferred; (ii) any
shares of Common Stock of the Company acquired by the Class B Investors pursuant
to Section 2 of that certain Stockholders' Agreement by and among the Parties
and of even date herewith (the "Stockholders' Agreement"); and (iii) any other
shares of Common Stock of the Company issued in respect of such shares described
in clauses (i) and (ii) above (because of stock splits, stock dividends,
reclassifications, recapitalizations, or similar events); provided, however,
that shares of Common Stock which are Class B Registrable Shares shall cease to
be Class B Registrable Shares upon any sale pursuant to a Registration
Statement, Section 4(1) of the Securities Act or Rule 144 under the Securities
Act. Wherever reference is made in this Agreement to a request or consent of
holders of a certain percentage of Class B Registrable Shares, the determination
of such percentage shall include shares of Common Stock issuable upon conversion
of the Class B Preferred even if such conversion has not yet been effected.

                  "Class C Registrable Shares" means (i) the shares of Common
Stock issued or issuable upon conversion of the Class C Preferred; (ii) any
shares of Common Stock of the Company acquired by the Class C Investors pursuant
to Section 2 of that certain Stockholders' Agreement by and among the Parties
and of even date herewith (the "Stockholders' Agreement"); (iii) any shares of
Common Stock of the Company issuable upon exercise of the Warrants (as defined
in that certain Convertible Class C Stock and Warrant Purchase Agreement of even
date herewith); and (iv) any other shares of Common Stock of the Company issued
in respect of such shares described in clauses (i) and (ii) above (because of
stock splits, stock dividends, reclassifications, recapitalizations, or similar
events); provided, however, that shares of Common Stock which are Class C
Registrable Shares shall cease to be Class C Registrable Shares upon any sale
pursuant to a Registration Statement, Section 4(1) of the Securities Act or Rule
144 under the Securities Act. Wherever reference is made in this Agreement to a
request or consent of holders of a certain percentage of Class C Registrable
Shares, the determination of such percentage shall include shares of Common
Stock issuable upon conversion of the Class C Preferred even if such conversion
has not yet been effected.

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                  "Commission" means the Securities and Exchange Commission, or
any other Federal agency at the time administering the Securities Act.

                  "Exchange Act" means the Securities Exchange Act of 1934, as
amended, or any similar Federal statute, and the rules and regulations of the
Commission issued under such Act, as they each may, from time to time, be in
effect.

                  "Registrable Shares" means the Class A Registrable Shares, the
Class B Registrable Shares and the Class C Registrable Shares, either
individually or collectively, depending upon the context.

                  "Registration Statement" means a registration statement filed
by the Company with the Commission for a public offering and sale of securities
of the Company (other than a registration statement on Form S-8 or Form S-4, or
their successors, or any other form for a limited purpose, or any registration
statement covering only securities proposed to be issued in exchange for
securities or assets of another corporation).

                  "Securities Act" means the Securities Act of 1933, as amended,
or any similar Federal statute, and the rules and regulations of the Commission
issued under such Act, as they each may, from time to time, be in effect.

                  "Shares" means the Class A Preferred, the Class B Preferred
and the Class C Preferred, either individually or collectively, depending upon
the context.

                  "Stockholders" means the Investors and any persons or entities
to whom the rights granted under this Article 1 are transferred by the
Investors, their successors or assigns pursuant to Section 3 of the
Stockholders' Agreement or Article II hereof.

            1.2 Sale or Transfer of Shares; Legend.

                  (a) The Shares and the Registrable Shares and shares issued in
respect of the Shares or the Registrable Shares shall not be sold or transferred
unless either (i) they first shall have been registered under the Securities
Act, or (ii) the Company first shall have been furnished with an opinion of
legal counsel, reasonably satisfactory to the Company, to the effect that such
sale or transfer is exempt from the registration requirements of the Securities
Act.

                  (b) Notwithstanding the foregoing, no registration or opinion
of counsel shall be required for a transfer made in accordance with Rule 144
under the Securities Act or with the terms of Section 3 of the Stockholders'
Agreement.

                  (c) Each certificate representing the Shares and the
Registrable Shares and shares issued in respect of the Shares or the Registrable
Shares shall bear legends substantially in the following forms:

                                     - 3 -
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            The shares represented by this certificate have not been registered
            under the Securities Act of 1933, as amended, and may not be
            offered, sold or otherwise transferred, pledged or hypothecated
            unless and until such shares are registered under such Act or an
            opinion of counsel satisfactory to the Company is obtained to the
            effect that such registration is not required.

            The shares of stock represented by this certificate are subject to
            the terms of a Stockholders' Agreement between the Company and the
            registered owner of this certificate (or the registered owner's
            predecessor in interest). Such Agreement is available for inspection
            without charge at the office of the Treasurer of the Company.

            The foregoing legends shall be removed from the certificates
representing any Registrable Shares, at the request of the holder thereof, at
such time as they become eligible for resale pursuant to Rule 144(k) under the
Securities Act.

                  (d) The Company agrees, upon the request of an Investor, to
make available to an Investor and to any prospective transferee of any Shares or
Registrable Shares of an Investor the information concerning the Company
described in Rule 144A(d)(4) under the Securities Act.

            1.3 Required Registrations.

                  (a) Class A Preferred.

                  (i) At any time after the earlier of four years from the date
of the Closing or the closing of the Company's first underwritten public
offering of shares of Common Stock pursuant to a Registration Statement, a
Stockholder or Stockholders holding in the aggregate at least 40% of the Class A
Registrable Shares may request, in writing, that the Company effect the
registration on Form S-1 or Form S-2 (or any successor form) of Class A
Registrable Shares owned by such Stockholder or Stockholders covering at least
33% of the then outstanding Class A Registrable Shares or any lesser percentage
provided that the anticipated aggregate offering price is at least $5,000,000
(based on the then current market price or fair value), provided, however, that
a Stockholder may not make such a request after such Stockholder has become
eligible to sell, transfer or otherwise convey all of such Stockholder's Class A
Registrable Shares pursuant to Rule 144 under the Securities Act in any
three-month period. If the holders initiating the registration intend to
distribute the Class A Registrable Shares by means of an underwriting, they
shall so advise the Company in their request. In the event such registration
involves an underwriting, the right of other Class A Stockholders to participate
shall be conditioned on such Stockholders' participation in such underwriting.
Upon

                                     - 4 -
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receipt of any such request, the Company shall promptly give written notice of
such proposed registration to all Class A Stockholders. Such Stockholders shall
have the right, by giving written notice to the Company within thirty (30) days
after the Company provides its notice, to elect to have included in such
registration such of their Class A Registrable Shares as such Stockholders may
request in such notice of election, subject to the approval of the underwriter
managing the offering. The Company shall, as expeditiously as possible, use its
best efforts to effect the registration, on Form S-1 or Form S-2 (or any
successor form), of all Class A Registrable Shares which the Company has been
requested to so register.

                  (ii) At any time after the Company becomes eligible to file a
Registration Statement on Form S-3 (or any successor form relating to secondary
offerings), holders of Common Stock issued or issuable upon conversion of the
Class A Preferred Stock will have the right to require the Company to effect an
unlimited number of Registration Statements on Form S-3 (or such successor form)
of Class A Registrable Shares having an aggregate offering price in each
registration on Form S-3 in excess of $500,000 (based on the then current public
market price). Such Stockholders shall have the right, by giving written notice
to the Company within thirty (30) days after the Company provides its notice, to
elect to have included in such registration such of their Class A Registrable
Shares as such Stockholders may request in such notice of election. The Company
shall, as expeditiously as possible, use its best efforts to effect the
registration on Form S-3, or such successor form, of all Class A Registrable
Shares which the Company has been requested to register.

                  (iii) Subject to the terms of Section 1.4(b) hereof, the
Company shall be required to effect two registrations pursuant to paragraph (a)
above and an unlimited number of registrations pursuant to paragraph (b) above;
provided, however, that the Company shall not be required to effect any
registration (other than on Form S-3 or any successor form relating to secondary
offerings) within six (6) months after the effective date of any other
Registration Statement of the Company, provided that the Class A Stockholders
were provided an opportunity to effect the sale of Class A Registrable Shares
pursuant to such Registration Statement; and provided further that the Company
shall not be required to effect more than two registrations pursuant to
paragraph (b) above in any 12-month period.

                  (iv) If a the time of any request to register Class A
Registrable Shares pursuant to this subsection 1.3(a), the Company is engaged or
has fixed plans to engage within thirty (30) days of the time of the request in
a registered public offering as to which the Stockholders may include Class A
Registrable Shares pursuant to subsection 1.4 or is engaged in any other
activity which, in the good faith determination of the Company's Board of
Directors, would be adversely affected by the requested registration to the
material detriment of the Company, then the Company may at its option direct
that such request be delayed for a period not in excess of 180 days from the
effective date of such offering or the date of commencement of such other
material activity, as the case may be, such right to delay a request to be
exercised by the Company not more than once in any two year period.

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                  (b) Class B Preferred.

                  (i) At any time after the earlier of four years from the date
of the Closing or the closing of the Company's first underwritten public
offering of shares of Common Stock pursuant to a Registration Statement, a
Stockholder or Stockholders holding in the aggregate at least 40% of the Class B
Registrable Shares may request, in writing, that the Company effect the
registration on Form S-1 or Form S-2 (or any successor form) of Class B
Registrable Shares owned by such Stockholder or Stockholders covering at least
33% of the then outstanding Class B Registrable Shares or any lesser percentage
provided that the anticipated aggregate offering price is at least $5,000,000
(based on the then current market price or fair value), provided, however, that
a Stockholder may not make such a request after such Stockholder has become
eligible to sell, transfer or otherwise convey all of such Stockholder's Class B
Registrable Shares pursuant to Rule 144 under the Securities Act in any
three-month period. If the holders initiating the registration intend to
distribute the Class B Registrable Shares by means of an underwriting, they
shall so advise the Company in their request. In the event such registration
involves an underwriting, the right of other Class B Stockholders to participate
shall be conditioned on such Stockholders' participation in such underwriting.
Upon receipt of any such request, the Company shall promptly give written notice
of such proposed registration to all Class B Stockholders. Such Stockholders
shall have the right, by giving written notice to the Company within thirty (30)
days after the Company provides its notice, to elect to have included in such
registration such of their Class B Registrable Shares as such Stockholders may
request in such notice of election, subject to the approval of the underwriter
managing the offering. The Company shall, as expeditiously as possible, use its
best efforts to effect the registration, on Form S-1 or Form S-2 (or any
successor form), of all Class B Registrable Shares which the Company has been
requested to so register.

                  (ii) At any time after the Company becomes eligible to file a
Registration Statement on Form S-3 (or any successor form relating to secondary
offerings), holders of Common Stock issued or issuable upon conversion of the
Class B Preferred Stock will have the right to require the Company to effect an
unlimited number of Registration Statements on Form S-3 (or such successor form)
of Class B Registrable Shares having an aggregate offering price in each
registration on Form S-3 in excess of $500,000 (based on the then current public
market price). Such Stockholders shall have the right, by giving written notice
to the Company within thirty (30) days after the Company provides its notice, to
elect to have included in such registration such of their Class B Registrable
Shares as such Stockholders may request in such notice of election. The Company
shall, as expeditiously as possible, use its best efforts to effect the
registration on Form S-3, or such successor form, of all Class B Registrable
Shares which the Company has been requested to register.

                  (iii) Subject to the terms of Section 1.4(b) hereof, the
Company shall be required to effect two registrations pursuant to paragraph (a)
above and an unlimited number of registrations pursuant to paragraph (b) above;
provided, however, that the Company shall not be required to effect any
registration (other than on Form S-3 or any

                                     - 6 -
<PAGE>

successor form relating to secondary offerings) within six (6) months after the
effective date of any other Registration Statement of the Company, provided that
the Class B Stockholders were provided an opportunity to effect the sale of
Class B Registrable Shares pursuant to such Registration Statement; and provided
further that the Company shall not be required to effect more than two
registrations pursuant to paragraph (b) above in any 12-month period.

                  (iv) If a the time of any request to register Class B
Registrable Shares pursuant to this subsection 1.3(b), the Company is engaged or
has fixed plans to engage within thirty (30) days of the time of the request in
a registered public offering as to which the Stockholders may include Class B
Registrable Shares pursuant to subsection 1.4 or is engaged in any other
activity which, in the good faith determination of the Company's Board of
Directors, would be adversely affected by the requested registration to the
material detriment of the Company, then the Company may at its option direct
that such request be delayed for a period not in excess of 180 days from the
effective date of such offering or the date of commencement of such other
material activity, as the case may be, such right to delay a request to be
exercised by the Company not more than once in any two year period.

            (c) Class C Preferred.

                  (i) At any time after the earlier of four years from the date
of the Closing or the closing of the Company's first underwritten public
offering of shares of Common Stock pursuant to a Registration Statement, a
Stockholder or Stockholders holding in the aggregate at least 40% of the Class C
Registrable Shares may request, in writing, that the Company effect the
registration on Form S-1 or Form S-2 (or any successor form) of Class C
Registrable Shares owned by such Stockholder or Stockholders covering at least
33% of the then outstanding Class C Registrable Shares or any lesser percentage
provided that the anticipated aggregate offering price is at least $5,000,000
(based on the then current market price or fair value), provided, however, that
a Stockholder may not make such a request after such Stockholder has become
eligible to sell, transfer or otherwise convey all of such Stockholder's Class C
Registrable Shares pursuant to Rule 144 under the Securities Act in any
three-month period. If the holders initiating the registration intend to
distribute the Class C Registrable Shares by means of an underwriting, they
shall so advise the Company in their request. In the event such registration
involves an underwriting, the right of other Class C Stockholders to participate
shall be conditioned on such Stockholders' participation in such underwriting.
Upon receipt of any such request, the Company shall promptly give written notice
of such proposed registration to all Class C Stockholders. Such Stockholders
shall have the right, by giving written notice to the Company within thirty (30)
days after the Company provides its notice, to elect to have included in such
registration such of their Class C Registrable Shares as such Stockholders may
request in such notice of election, subject to the approval of the underwriter
managing the offering. The Company shall, as expeditiously as possible, use its
best efforts to effect the registration, on Form S-1 or Form S-2 (or any
successor form), of all Class C Registrable Shares which the Company has been
requested to so register.

                                     - 7 -
<PAGE>

                  (ii) At any time after the Company becomes eligible to file a
Registration Statement on Form S-3 (or any successor form relating to secondary
offerings), holders of Common Stock issued or issuable upon conversion of the
Class C Preferred Stock will have the right to require the Company to effect an
unlimited number of Registration Statements on Form S-3 (or such successor form)
of Class C Registrable Shares having an aggregate offering price in each
registration on Form S-3 in excess of $500,000 (based on the then current public
market price). Such Stockholders shall have the right, by giving written notice
to the Company within thirty (30) days after the Company provides its notice, to
elect to have included in such registration such of their Class C Registrable
Shares as such Stockholders may request in such notice of election. The Company
shall, as expeditiously as possible, use its best efforts to effect the
registration on Form S-3, or such successor form, of all Class C Registrable
Shares which the Company has been requested to register.

                  (iii) Subject to the terms of Section 1.4(b) hereof, the
Company shall be required to effect two registrations pursuant to paragraph (a)
above and an unlimited number of registrations pursuant to paragraph (b) above;
provided, however, that the Company shall not be required to effect any
registration (other than on Form S-3 or any successor form relating to secondary
offerings) within six (6) months after the effective date of any other
Registration Statement of the Company, provided that the Class C Stockholders
were provided an opportunity to effect the sale of Class C Registrable Shares
pursuant to such Registration Statement; and provided further that the Company
shall not be required to effect more than two registrations pursuant to
paragraph (b) above in any 12-month period.

                  (iv) If a the time of any request to register Class C
Registrable Shares pursuant to this subsection 1.3(c), the Company is engaged or
has fixed plans to engage within thirty (30) days of the time of the request in
a registered public offering as to which the Stockholders may include Class C
Registrable Shares pursuant to subsection 1.4 or is engaged in any other
activity which, in the good faith determination of the Company's Board of
Directors, would be adversely affected by the requested registration to the
material detriment of the Company, then the Company may at its option direct
that such request be delayed for a period not in excess of 180 days from the
effective date of such offering or the date of commencement of such other
material activity, as the case may be, such right to delay a request to be
exercised by the Company not more than once in any two year period.

            1.4 Incidental Registration.

                  (a) Whenever the Company proposes to file a Registration
Statement (including pursuant to subsection 1.3) at any time and from time to
time, it will, prior to such filing, give written notice to all Stockholders of
its intention to do so and, upon the written request of a Stockholder or
Stockholders given within twenty (20) days after the Company provides such
notice (which request shall state the intended method of disposition of such
Registrable Shares), the Company shall use its best efforts to cause all
Registrable Shares which the Company has been requested by such Stockholder or
Stockholders to register to be registered

                                     - 8 -
<PAGE>

under the Securities Act to the extent necessary to permit their sale or other
disposition in accordance with the intended methods of distribution specified in
the request of such Stockholder or Stockholders; provided that the Company shall
have the right to postpone or withdraw any registration effected pursuant to
this subsection 1.4 without obligation to any Stockholder.

                  (b) In connection with any offering under this subsection 1.4
involving an underwriting, the Company shall not be required to include any
Registrable Shares in such underwriting unless the holders thereof accept the
terms of the underwriting as agreed upon between the Company and the
underwriters selected by it, and then only in such quantity as will not, in the
opinion of the underwriters, have a material adverse effect on the success of
the offering by the Company. If in the opinion of the managing underwriter the
registration of all, or part of, the Registrable Shares which the holders have
requested to be included would materially and adversely affect such public
offering, then the Company shall be required to include in the underwriting only
that number of Registrable Shares, if any, which the managing underwriter
believes may be sold without causing such adverse effect; provided that no
persons or entities other than the Company, the Stockholders and persons or
entities holding registration rights granted in accordance with subsection 1.11
hereof shall be permitted to include securities in the offering. If the number
of Registrable Shares to be included in the underwriting in accordance with the
foregoing is less than the total number of shares which the holders of
Registrable Shares have requested to be included, then the number of shares to
be offered shall be reduced or limited in the following order of priority: (x)
first, the securities proposed by the Company to be sold for its own account
(except where the Company is the party that initiated such registration); (y)
second, the number of shares to be offered by all other holders of securities of
the Company other than the holder of Registrable Shares or other holders who
have registration rights to the extent necessary to reduce the total number of
shares as recommended by such managing underwriters; and (z) third, if further
reduction or limitation is required, the number of shares to be offered for the
account of the Stockholders shall be reduced or limited on a pro rata basis in
proportion to the relative number of Registrable Shares of the Stockholders
participating in such registration. Notwithstanding the foregoing sentence, in
the case of the first registration affected pursuant to Section 1.3(a), 1.3(b)
or 1.3(c) hereof, if the number of Registrable Shares to be included in such
underwriting is less than the total number of shares which the holders of
Registrable Shares have requested to be included, then the number of shares to
be offered shall be reduced or limited on a pro rata basis in proportion to the
relative number of Registrable Shares of the Stockholders participating in such
registration (regardless of whether pursuant to Section 1.3 or this Section
1.4), provided, however, that if there is a such a reduction or limitation, then
the Stockholder that has not requested such a registration shall be deemed to
have expended one of their two registrations pursuant to Section 1.3(a)(i),
1.3(b)(i) or 1.3(c)(i), as the case may be, as long as such Stockholder has been
able to include in such registration at least 66 2/3% of the Registrable Shares
that such stockholder desired to include in such registration.

                  (c) Withdrawal Election. If, as a result of the proration
provisions of the Section 1.4, any Stockholder shall not be entitled to include
at least 50% of the Registrable

                                     - 9 -
<PAGE>

Shares in such Incidental Registration pursuant to Section 1.4(a) that such
Stockholder has requested to be included, such Stockholder may elect to withdraw
his, her or its request to include Registrable Shares in such registration (a
"Withdrawal Election") without incurring any liability for his, her or its fees
and expenses; provided, however, that a Withdrawal Election shall be irrevocable
and, after making a Withdrawal Election, a Stockholder shall no longer have any
right to include Registrable Shares in the Registration as to which such
Withdrawal Election is made.

            1.5 Registration Procedures. If and whenever the Company is required
by the provisions of this Agreement to use its best efforts to effect the
registration of any of the Registrable Shares under the Securities Act, the
Company shall:

            (a) Prepare and file with the Commission a Registration Statement
      with respect to such Registrable Shares and use its best efforts to cause
      such Registration Statement to become effective; provided that before
      filing a Registration Statement or prospectus or any amendment or
      supplement thereto, including documents incorporated by reference after
      the initial filing of any Registration Statement, the Company shall
      furnish to the Stockholders of the Registrable Shares covered by such
      Registration Statement (such shares, "Registered Shares") and the
      underwriters, if any, copies of all such documents proposed to be filed,
      which documents will be subject to the review of such Stockholders and
      underwriters.

            (b) Prepare and file with the Commission such amendments and
      post-effective amendments to a Registration Statement as may be necessary
      to keep such registration effective for a period of six (6) months or
      until the Stockholder or Stockholders have completed the distribution
      described in the Registration Statement relating thereto, whichever first
      occurs; provided, however, that the Company, in good faith, may delay the
      filing of any amendment or supplement to the Registration Statement for a
      reasonable period of time, not to exceed 120 days, in order to permit the
      Company (A) to effect disclosure or disposition or consummation of any
      transaction requiring confidential treatment which is being actively
      pursued at such time and which would require disclosure in the
      Registration Statement or (B) to negotiate, effect or complete any
      transaction which the Company reasonably believes might be jeopardized,
      delayed or made more costly to the Company by disclosure in the
      Registration Statement; and provided further, however, that (i) such 6
      month period shall be extended for a period of time equal to the period
      the Stockholder refrains from selling any securities included in such
      registration in accordance with the provisions of Section 1.10 hereof;
      (ii) such 6 month period shall be extended by the number of days during
      the period from and including the date of the giving of notice pursuant to
      Section 1.5(e) hereof to and including the date when each Stockholder of
      Registrable Shares covered by such Registration Statement shall have
      received the copies of the supplemented or amended prospectus contemplated
      by Section 1.5(e) hereof; and (iii) in the case of any registration of
      Registrable Shares on Form S-3 which are intended to be offered on a
      continuous or

                                     - 10 -
<PAGE>

      delayed basis, such 6 month period shall be extended, if necessary, to
      keep the Registration Statement effective until all such Registrable
      Shares are sold, provided that Rule 415, or any successor rule under the
      Securities Act, permits an offering on a continuous or delayed basis, and
      provided further that applicable rules under the Securities Act governing
      the obligation to file a post-effective amendment permit, in lieu of
      filing a post-effective amendment which (y) includes any prospectus
      required by Section l0(a)(3) of the Securities Act or (z) reflects facts
      or events representing a material or fundamental change in the information
      set forth in the Registration Statement, the incorporation by reference in
      the Registration Statement of periodic reports filed pursuant to Section
      13 or 15(d) of the Exchange Act that contain the information required to
      be included in (y) and (z) above;

            (c) Cause the related prospectus to be supplemented by any required
      prospectus supplement, and as so supplemented, to be filed pursuant to
      Rule 424 under the Securities Act; and comply with the provisions of the
      Securities Act with respect to the disposition of all securities covered
      by such Registration Statement during such period in accordance with the
      intended methods of disposition by the sellers thereof set forth in such
      Registration Statement or supplement to such prospects;

            (d) Furnish such number of prospectuses and other documents incident
      thereto, including any amendment of or supplement to the prospectus as a
      Stockholder from time to time may reasonably request;

            (e) Notify each seller of Registered Shares covered by such
      Registration Statement at any time when a prospectus relating thereto is
      required to be delivered under the Securities Act of the happening of any
      event as a result of which the prospectus included in such Registration
      Statement, as then in effect, includes an untrue statement of a material
      fact or omits to state a material fact required to be stated therein or
      necessary to make the statements therein, in the light of the
      circumstances under which they were made, not misleading, and at the
      request of any such seller, prepare and furnish to such seller a
      reasonable number of copies of a supplement to or an amendment of such
      prospectus as may be necessary so that, as thereafter delivered to the
      purchasers of such shares, such prospectus shall not include an untrue
      statement of a material fact or omit to state a material fact required to
      be stated therein or necessary to make the statements therein, in the
      light of the circumstances under which they were made, not misleading;

            (f) Cause all such Registered Shares to be listed on each securities
      exchange on which similar securities issued by the Company are then listed
      or, if not then listed, cause such Registered Shares to be included in
      whatever exchange or national automated quotation system the Board of
      Directors determines is appropriate;

                                     - 11 -
<PAGE>

            (g) Provide a transfer agent and registrar for all Registered Shares
      and a CUSIP number for all such Registered Shares, in each case not later
      than the effective date of such registration;

            (h) Make available for inspection during regular business hours by
      any seller of Registrable Shares, any underwriter participating in any
      disposition pursuant to such Registration Statement, and any attorney,
      accountant or other agent retained by any such seller or underwriter
      (collectively, the "Inspectors"), all financial and other records,
      pertinent corporate documents and properties of the Company (collectively
      the "Records") as shall be reasonably necessary to enable them to exercise
      their due diligence responsibility, and cause the Company's officers,
      directors, employees and independent accountants to supply all information
      reasonably requested by such seller, underwriter, attorney or accountant
      in connection with such Registration Statement. Records which the Company
      determines, in good faith, to be confidential and which it notifies the
      Inspectors are confidential shall not be disclosed by the Inspectors
      unless (A) the disclosure of such Records is, in the opinion of counsel
      for the selling Stockholders, reasonably necessary to avoid or correct any
      misstatement or omission in the Registration Statement, (B) the release of
      such Records is ordered pursuant to a subpoena or other order from a court
      of competent jurisdiction, or (C) the disclosure of such Records is
      required by any governmental regulatory body with jurisdiction over any
      seller of Registrable Shares. Such seller, upon learning, that disclosure
      of such Records is sought in a court of competent jurisdiction, shall
      notify the Company and allow the Company, at its expense, to undertake
      appropriate action to prevent disclosure of the Records deemed
      confidential;

            (i) Cooperate with the sellers of Registered Shares and the managing
      underwriter(s), if any, to facilitate the timely preparation and delivery
      of certificates representing the Registered Shares to be sold, without any
      restrictive legends, in such denominations and registered in such names as
      the managing underwriter(s) may request at least two business days prior
      to any sale thereof to the underwriters, if applicable;

            (j) Participate, to the extent reasonably requested by the managing
      underwriter for the offering or the selling Stockholders, in efforts to
      sell the Registrable Shares under the offering (including, without
      limitation, participating in "roadshow" meetings with prospective
      investors) that would be customary for underwritten primary offerings of a
      comparable percent of equity securities by the Company;

            (k) Obtain from its accountants "cold-comfort" letters, dated the
      effective date of the Registration Statement and the date of the closing
      of the sale of the Registered Shares, and addressed to the Company and the
      selling Stockholders, in form and substance as are customarily issued in
      connection with underwritten public offerings;

                                     - 12 -
<PAGE>

            (l) Obtain from its counsel an opinion, addressed to the selling
      Stockholders, with respect to the offering in form and substance
      reasonably satisfactory to a majority-in-interest of such Stockholders;

            (m) Otherwise use its best efforts to comply with all applicable
      rules and regulations of the Commission, and make available to its
      security Stockholders, as soon as reasonably practicable, an earnings
      statement covering the period of at least twelve months, but not more than
      eighteen months, beginning with the first month after the effective date
      of the Registration Statement, which earnings statement shall satisfy the
      provisions of Section 11(a) of the Securities Act;

            (n) In connection with any underwritten offering pursuant to a
      Registration Statement filed pursuant to Section 1 hereof, the Company
      will enter into any underwriting agreement reasonably necessary to effect
      the offer and sale of Common stock, provided such underwriting agreement
      contains customary underwriting, indemnification and contribution
      provisions; provided, however, that no Stockholder will be liable for
      indemnification or contribution in excess of the net proceeds such
      Stockholder received in the offering;

            (o) Use its best efforts to register or qualify such Registrable
      Shares under such other securities or blue sky laws of such jurisdictions
      as any seller reasonably requests and do any and all other acts and things
      which may be reasonably necessary or advisable to enable such seller to
      consummate the disposition in such jurisdictions of the Registrable Shares
      owned by such seller provided that the Company will not be required to (i)
      qualify generally to do business in any jurisdiction where it would not
      otherwise be required to qualify but for this subparagraph, (ii) subject
      itself to taxation in any such jurisdiction or (iii) consent to general
      service of process in any such jurisdiction);

            (p) Use its best efforts to cause such Registrable Shares covered by
      such Registration Statement to be registered with or approved by such
      other governmental agencies or authorities as may be necessary to enable
      the sellers thereof to consummate the disposition of such Registrable
      Shares; and

            (q) Take all such other actions as the underwriters, if any, and a
      majority-in-interest of the selling Stockholders reasonably request in
      order to expedite or facilitate the disposition of such Registrable Shares
      (including, without limitation, effecting a stock split or combination of
      shares).

            1.6 Allocation of Expenses. The Company will pay all Registration
Expenses of all registrations under this Agreement; provided, however, that if a
registration under subsection 1.3 is withdrawn at the request of the Class B or
Class C Stockholders, as applicable, requesting such registration (other than as
a result of information concerning the business or financial condition of the
Company which is made known to the Stockholders after

                                     - 13 -
<PAGE>

the date on which such registration was requested) and if the requesting
Stockholders, elect not to have such registration counted as a registration
requested under subsection 1.3, the requesting Stockholders shall pay the
Registration Expenses of such registration pro rata in accordance with the
number of their Registrable Shares included in such registration. For purposes
of this Section, the term "Registration Expenses" shall mean all expenses
incurred by the Company in complying with this Article 1, including, without
limitation, all registration and filing fees, exchange listing fees, printing
expenses, fees and disbursements of counsel for the Company and the fees and
expenses of one counsel selected by the selling Stockholders, as applicable, to
represent the selling Stockholders, as applicable, state Blue Sky fees and
expenses, and the expense of any special audits incident to or required by any
such registration, but excluding underwriting discounts, selling commissions and
the fees and expenses of the selling Stockholders' own counsel (other than the
counsel selected to represent all selling Stockholders).

            1.7 Indemnification and Contribution. In the event of any
registration of any of the Registrable Shares under the Securities Act pursuant
to this Agreement, the Company will indemnify and hold harmless the seller of
such Registrable Shares, each underwriter of such Registrable Shares, and each
other person, if any, who controls such seller or underwriter within the meaning
of the Securities Act or the Exchange Act against any losses, claims, damages or
liabilities, joint or several, to which such seller, underwriter or controlling
person may become subject under the Securities Act, the Exchange Act, state
securities or Blue Sky laws or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon any untrue statement or alleged untrue statement of any material fact
contained in any Registration Statement under which such Registrable Shares were
registered under the Securities Act, any preliminary prospectus or final
prospectus contained in the Registration Statement, or any amendment or
supplement to such Registration Statement, or arise out of or are based upon the
omission or alleged omission to state a material fact required to be stated
therein or necessary to make the statements therein not misleading; and the
Company will promptly reimburse such seller, underwriter and each such
controlling person upon demand for any legal or any other expenses reasonably
incurred by such seller, underwriter or controlling person in connection with
investigating or defending any such loss, claim, damage, liability or action;
provided, however, that the Company will not be liable in any such case to the
extent that any such loss, claim, damage or liability arises out of or is based
upon any untrue statement or omission made in such Registration Statement,
preliminary prospectus or prospectus, or any such amendment or supplement, in
reliance upon and in conformity with information furnished to the Company, in
writing, by or on behalf of such seller, underwriter or controlling person
specifically for use in the preparation thereof.

            In the event of any registration of any of the Registrable Shares
under the Securities Act pursuant to this Agreement, each seller of Registrable
Shares, severally and not jointly, will indemnify and hold harmless the Company,
each of its directors and officers and each underwriter (if any) and each
person, if any, who controls the Company or any such underwriter within the
meaning of the Securities Act or the Exchange Act, against any losses, claims,
damages or liabilities, joint or several, to which the Company, such directors
and

                                     - 14 -
<PAGE>

officers, underwriter or controlling person may become subject under the
Securities Act, Exchange Act, state securities or Blue Sky laws or otherwise,
insofar as such losses, claims, damages or liabilities (or actions in respect
thereof) arise out of or are based upon any untrue statement or alleged untrue
statement of a material fact contained in any Registration Statement under which
such Registrable Shares were registered under the Securities Act, any
preliminary prospectus or final prospectus contained in the Registration
Statement, or any amendment or supplement to the Registration Statement, or
arise out of or are based upon any omission or alleged omission to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading, if but only if, the statement or omission was made in
reliance upon and in conformity with information furnished in writing to the
Company by or on behalf of such seller, specifically for use in connection with
the preparation of such Registration Statement, prospectus, amendment or
supplement; provided, however, that the obligations of such Stockholders
hereunder shall be limited to an amount equal to the proceeds to each
Stockholder of Registrable Shares sold as contemplated herein.

            Each party entitled to indemnification under this subsection 1.7
(the "Indemnified Party") shall give notice to the party required to provide
indemnification (the "Indemnifying Party") promptly after such Indemnified Party
has actual knowledge of any claim as to which indemnity may be sought, and shall
permit the Indemnifying Party to assume the defense of any such claim or any
litigation resulting therefrom; provided, that counsel for the Indemnifying
Party, who shall conduct the defense of such claim or litigation, shall be
approved by the Indemnified Party (whose approval shall not be unreasonably
withheld); and, provided, further, that the failure of any Indemnified Party to
give notice as provided herein shall not relieve the Indemnifying Party of its
obligations under this Article 1. The Indemnified Party may participate in such
defense at such party's expense; provided, however, that the Indemnifying Party
shall pay such expense if representation of such Indemnified Party by the
counsel retained by the Indemnifying Party would be inappropriate due to actual
or potential differing interests between the Indemnified Party and any other
party represented by such counsel in such proceeding. No Indemnifying Party in
the defense of any such claim or litigation shall, except with the consent of
each Indemnified Party, consent to entry of any judgment or enter into any
settlement which does not include as an unconditional term thereof the giving by
the claimant or plaintiff to such Indemnified Party of a release from all
liability in respect of such claim or litigation, and no Indemnified Party shall
consent to entry of any judgment or settle such claim or litigation without the
prior written consent of the Indemnifying Party.

            In order to provide for just and equitable contribution to joint
liability under the Securities Act in any case in which either (i) any holder of
Registrable Shares exercising rights under this Agreement, or any controlling
person of any such holder, makes a claim for indemnification pursuant to this
subsection 1.7 but it is judicially determined (by the entry of a final judgment
or decree by a court of competent jurisdiction and the expiration of time to
appeal or the denial of the last right of appeal) that such indemnification may
not be enforced in such case notwithstanding the fact that this subsection 1.7
provides for indemnification in such case, or (ii) contribution under the
Securities Act may be required on the part of any such selling

                                     - 15 -
<PAGE>

Stockholder, as applicable, or any such controlling person in circumstances for
which indemnification is provided under this subsection 1.7; then, in each such
case, the Company and such Stockholder will contribute to the aggregate losses,
claims, damages, or liabilities to which they may be subject (after contribution
from others) in such proportion as is appropriate to reflect the relative fault
of the Stockholder on the one hand and the Company on the other in connection
with the action that resulted in such loss, claim, damage or liability, as well
as any other relevant equitable considerations. The relative fault of the
indemnifying party and of the indemnified party shall be determined by a court
of law by reference to, among other things, whether the untrue or alleged untrue
statement of a material fact or the omission to state a material fact relates to
information supplied by the indemnifying party or the indemnified party and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such statement or omission; provided, that in no event shall
any contribution by a holder exceed the proceeds to it of all Registrable Shares
sold by it pursuant to such Registration Statement, and (B) no person or entity
guilty of fraudulent misrepresentation, within the meaning of Section 11(f) of
the Securities Act, shall be entitled to contribution from any person or entity
who is not guilty of such fraudulent misrepresentation.

            1.8 Indemnification with Respect to Underwritten Offering. In the
event that Registrable Shares are sold pursuant to a Registration Statement in
an underwritten offering pursuant to subsection 1.3(a), 1.3(b) or 1.3(c), the
Company agrees to enter into an underwriting agreement containing customary
representations and warranties of an issuer of the securities being registered
and customary covenants and agreements to be performed by such issuer, including
without limitation customary provisions with respect to indemnification by the
Company of the underwriters of such offering, provided that such agreement shall
not provide that the Stockholders are subject to indemnification obligations
greater than as set forth herein.

            1.9 Information by Holder. Each holder of Registrable Shares
included in any registration shall furnish to the Company such information
regarding such holder and the distribution proposed by such holder as the
Company may request in writing and as shall be required in connection with any
registration, qualification or compliance referred to in this Article 1.

            1.10 "Market Stand-Off Agreement.

                  (a) Each Stockholder, if requested by the Company and an
underwriter of Common Stock or other securities of the Company, shall agree not
to sell or otherwise transfer or dispose of any Registrable Shares or other
securities of the Company held by such Stockholder for a specified period of
time (not to exceed 180 days) following the effective date of a Registration
Statement; provided, that:

                  (i) such agreement shall only apply to the first such
            Registration Statement covering Common Stock of the Company to be
            sold on its behalf to the public in an underwritten offering; and

                                     - 16 -
<PAGE>

                  (ii) all Stockholders holding not less than the number of
            shares of Common Stock held by such Stockholder (including shares of
            Common Stock issuable upon the conversion of Shares, or other
            convertible securities, or upon the exercise of options, warrants or
            rights) and all officers and directors of the Company enter into
            similar agreements.

                  (c) The agreements described in subsection (a) above shall be
in writing in a form satisfactory to the Company and such underwriter. The
Company may impose stop-transfer instructions with respect to the Registrable
Shares or other securities subject to the foregoing restriction until the end of
the stand-off period.

            1.11 Limitations on Subsequent Registration Rights. The Company
shall not, without the prior written consent of Stockholders holding at least 66
2/3% of the Registrable Shares, enter into any agreement (other than this
Agreement) with any holder or prospective holder of any securities of the
Company which would allow such holder or prospective holder (a) to include
securities of the Company in any registration filed under subsection 1.3 or 1.4,
unless under the terms of such agreement, such holder or prospective holder may
include such securities in any such registration only on terms substantially
similar to the terms on which holders of Registrable Shares may include shares
in such registration, including the terms of Section 1.4(b) hereof; provided,
however, that under the terms of such agreement the number of Registrable Shares
to be included by the initiator of a demand registration pursuant to Section 1.3
hereof shall not be reduced to allow such holder or prospective holder to
include securities in such registration or (b) to make a demand registration
which could result in such registration statement being declared effective prior
to the initial public offering.

            1.12 Rule 144 Requirements. After the earliest of (i) the closing of
the sale of securities of the Company pursuant to a Registration Statement, (ii)
the registration by the Company of a class of securities under Section 12 of the
Exchange Act, or (iii) the issuance by the Company of an offering circular
pursuant to Regulation A under the Securities Act, the Company agrees to:

                  (a) Comply with the requirements of Rule 144(c) under the
Securities Act with respect to current public information about the Company;

                  (b) use its best efforts to file with the Commission in a
timely manner all reports and other documents required of the Company under the
Securities Act and the Exchange Act (at any time after it has become subject to
such reporting requirements); and

                  (c) furnish to any holder of Registrable Shares upon request
(i) a written statement by the Company as to its compliance with the
requirements of said Rule 144(c), and the reporting requirements of the
Securities Act and the Exchange Act (at any time after it has become subject to
such reporting requirements), (ii) a copy of the most recent annual

                                     - 17 -
<PAGE>

or quarterly report of the Company, and (iii) such other reports and documents
of the Company as such holder may reasonably request to avail itself of any
similar rule or regulation of the Commission allowing it to sell any such
securities without registration.

            1.13 Selection of Underwriter. In the case of any registration
effected pursuant to this Article I, the Company shall have the right to
designate the managing underwriter in any underwritten offering, subject to the
approval of the holders of a majority of the Registrable Shares requested to be
included in such offering, which approval shall not be unreasonably withheld.

            1.14 Mergers, Etc. The Company shall not, directly or indirectly,
enter into any merger, consolidation, or reorganization in which the Company
shall not be the surviving corporation unless the proposed surviving corporation
shall, prior to such merger, consolidation, or reorganization, agree in writing
to assume the obligations of the Company under this Article 1, and for that
purpose references hereunder to "Registrable Shares" shall be deemed to be
references to the securities that each Stockholder would be entitled to receive
in exchange for Registrable Shares under any such merger, consolidation, or
reorganization; provided, however, that the provisions of this Article I shall
not apply in the event of any merger, consolidation, or reorganization in which
the Company is not the surviving corporation if all Stockholders are entitled to
receive in exchange for their Registrable Shares consideration consisting solely
of (i) cash, (ii) securities of the acquiring corporation that may be
immediately sold to the public without registration under the Securities Act, or
(iii) securities of the acquiring corporation that the acquiring corporation has
agreed to register within ninety (90) days of completion of the transaction for
resale to the public pursuant to the Securities Act.

                                   ARTICLE II
                           TRANSFERS OF CERTAIN RIGHTS

            2.1 The rights granted to the Investors under this Agreement may be
transferred by such Investor to an affiliate, partner, shareholder or immediate
family member of such Investor or any transferee who after such transfer holds
at least 20% of the Investor's Registrable Shares; provided, however, that the
Company is given written notice by the transferee at the time of such transfer
stating the name and address of the transferee and identifying the securities
with respect to which such rights are being transferred, and that the Company
gives its consent to the transfer of rights to any transferee which is not an
affiliate, partner, shareholder, or immediate family member of the Investor,
which consent shall not be unreasonably withheld.

            2.2 Transferees. Any transferee to whom rights under this Agreement
are transferred shall, as a condition to such transfer, deliver to the Company a
written instrument by which such transferee agrees to be bound by the
obligations imposed upon the Investor under this Agreement to the same extent as
if such transferee were the Investor.

                                     - 18 -
<PAGE>

            2.3 Subsequent Transferees. A transferee to whom rights are
transferred pursuant to this Section 2 may not again transfer such rights to any
other person or entity, other than as provided in Subsection 2.1 or Subsection
2.2 above

                                   ARTICLE III
                                  MISCELLANEOUS

            3.1 No Inconsistent Agreements. The Company will not hereafter enter
into any agreement with respect to its securities which is inconsistent with or
violates the rights granted to the holders of Registrable Shares in this
Agreement.

            3.2 Adjustments Affecting Registrable Shares. The Company will not
take any action, or permit any change to occur, with respect to its securities
that would adversely affect the ability of the holders of Registrable Shares to
include such Registrable Shares in a registration undertaken pursuant to this
Agreement or that would adversely affect the marketability of such Registrable
Shares in any such registration (including, without limitation, effecting a
stock split or a combination of shares).

            3.3 Remedies. Any person having rights under any provision of this
Agreement will be entitled to enforce such rights specifically (without posting
any bond or other security), to recover damages caused by reason of any breach
of any provision of this Agreement and to exercise all other rights granted by
law.

            3.4 Amendments and Waivers. Except as otherwise provided herein, the
provisions of this Agreement may be amended and the Company may take action
herein prohibited, or omit to perform any act herein required to be performed by
it, if, but only if, the Company has obtained the written consent of holders of
at least 2/3 of each of the Class A, the Class B and the Class C Registrable
Shares then in existence.

            3.5 Successors and Assigns. All covenants and agreements in this
Agreement by or on behalf of any of the parties hereto will bind and inure to
the benefit of the respective successors and assigns of the parties hereto
whether so expressed or not. In addition, irrespective of whether any express
assignment has been made, the provisions of this Agreement that are for the
benefit of purchasers or holders of Registrable Shares are also for the benefit
of; and enforceable by, any subsequent holder permitted by Section 2.1.

            3.6 Governing Law. This Agreement shall be governed by, and
construed and enforced in accordance with, the laws of the State of Florida.
Each of the Company and each Investor hereby irrevocably and unconditionally
submit to the jurisdiction of the courts of the State of Florida and the United
States of America located in the State of Florida (the "Florida Courts") for
any litigation arising out of or relating to this Agreement and the transactions
contemplated hereby (and agree not to commence any litigation relating thereto
except in such courts), consent to service of process in such Florida Courts,
waive any objection to the laying of

                                     - 19 -
<PAGE>

venue of any such litigation in Alachua County, Florida, and agree not to plead
or claim in any Florida Court that such litigation brought therein has been
brought in any inconvenient forum.

            3.7 Term of Registration Rights. Notwithstanding anything to the
contrary contained herein, the registration rights of each holder of Registrable
Shares set forth in Section 1 shall terminate in their entirety on the fifth
anniversary of a Qualified Class A, Qualified Class B or Qualified Class C
Offering (each as defined in Article Fourth, Section B.5(a) of the Company's
Articles of Incorporation), as the case may be.

            3.8 Entire Agreement. This Agreement and the other documents
delivered pursuant hereto constitute the full and entire understanding and
agreement between the parties with regard to the subjects hereof and thereof.

            3.9 Notices. Any and all notices or elections permitted or required
to be made under this Agreement shall be in writing, signed by the party giving
such notice or election and shall be delivered personally, by courier or sent by
registered or certified mail, return receipt requested, to the Company and the
Stockholders at their respective addresses below:

      If to the Company to:

                  Regeneration Technologies, Inc.
                  One Innovation Drive
                  Alachua, Florida 32615
                  Attn: Richard R. Allen

                  with copy (which shall not constitute notice) to:

                  Piper & Marbury L.L.P.
                  1200 Nineteenth Street, N.W.
                  Washington, DC 20036
                  Attn: Theodore D. Segal, Esquire

      If to the Class C Investors to:

                  Medtronic Asset Management, Inc.
                  7000 Central Avenue, N.E.
                  Minneapolis, MN 55402
                  Attn: Vice President & Chief Development Officer

                  with copy to:

                                     - 20 -
<PAGE>

                  Medtronic Asset Management, Inc.
                  7000 Central Avenue, N.E.
                  Minneapolis, MN 55402
                  Attn: General Counsel

                  and

                  Stephens-Regeneration LLC
                  111 Center Street, Suite 2500
                  Little Rock, AR 72201
                  Attn: President

                  with copy to:

                  Stephens-Regeneration LLC
                  111 Center Street, Suite 2500
                  Little Rock, AR 72201
                  Attn: Jackson Farrow, Esquire

      If to the Class A or Class B Investors, to the addresses set forth below
their respective names in Exhibit A and Exhibit B hereto.

            3.10 Severability. In case any provision of this Agreement shall be
invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions of this Agreement or any provision of the other
Agreements shall not in any way be affected or impaired thereby.

            3.11 Titles and Subtitles. The titles of the sections and
subsections of this Agreement are for convenience of reference only and are not
to be considered in construing this Agreement.

            3.12 No Registration of Preferred Stock. The registration rights
contained herein apply only to the Company's Common Stock, and the Company shall
never be obligated to register any of the Class A Preferred, Class B Preferred
or the Class C Preferred.

            3.13 Counterparts. This Agreement may be executed in one or more
counterparts, each of which when so executed shall be deemed an original, and
all such counterparts taken together shall constitute one and the same
instrument.

                         [signatures begin on next page]

                                     - 21 -
<PAGE>

      IN WITNESS WHEREOF, this Agreement has been executed by the parties hereto
as of the day and year first written above.

      REGENERATION TECHNOLOGIES, INC.

By: /s/ James M. Grooms
   --------------------------------
Name: James M. Grooms
Its:  President

CLASS A STOCKHOLDERS

      JAMES M. GROOMS

      /s/ James M. Grooms
      ------------------------------

      UNIVERSITY OF FLORIDA TISSUE BANK

By:
   --------------------------------
Name: Nancy R. Holland
Its:  President

      UNIVERSITY OF FLORIDA RESEARCH FOUNDATION, INC.

By:
   --------------------------------
Name:
Its:

      LB I GROUP, INC.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 21 -
<PAGE>

      IN WITNESS WHEREOF, this Agreement has been executed by the parties hereto
as of the day and year first written above.

      REGENERATION TECHNOLOGIES, INC.

By: /s/ James M. Grooms
   --------------------------------
Name: James M. Grooms
Its:  President

CLASS A STOCKHOLDERS

      JAMES M. GROOMS

      /s/ James M. Grooms
      -----------------------------

      UNIVERSITY OF FLORIDA TISSUE BANK

By:
   --------------------------------
Name: Nancy R. Holland
Its:  President

      UNIVERSITY OF FLORIDA RESEARCH FOUNDATION, INC.

By: /s/ Thomas E. Walsh
   --------------------------------
Name: Thomas E. Walsh
Its:  Secretary 10-8-99

      LB I GROUP, INC.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 21 -
<PAGE>

      IN WITNESS WHEREOF, this Agreement has been executed by the parties hereto
as of the day and year first written above.

      REGENERATION TECHNOLOGIES, INC.

By: /s/ James M. Grooms
   --------------------------------
Name: James M. Grooms
Its:  President

CLASS A STOCKHOLDERS

      JAMES M. GROOMS

      /s/ James M. Grooms
      -----------------------------

      UNIVERSITY OF FLORIDA TISSUE BANK, INC. [ILLEGIBLE] 10/6/99

By: /s/ Nancy R. Holland
   --------------------------------
Name: Nancy R. Holland
Its:  President

      UNIVERSITY OF FLORIDA RESEARCH FOUNDATION, INC.

By:
   --------------------------------
Name:
Its:

      LB I GROUP, INC.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 21 -
<PAGE>

      IN WITNESS WHEREOF, this Agreement has been executed by the parties hereto
as of the day and year first written above

      REGENERATION TECHNOLOGIES, INC.

By:
   --------------------------------
Name: James M. Grooms
Its:  President

CLASS A STOCKHOLDERS

      JAMES M. GROOMS

      ------------------------------

      UNIVERSITY OF FLORIDA TISSUE BANK

By:
   --------------------------------
Name: Nancy R. Holland
Its:  President

      UNIVERSITY OF FLORIDA RESEARCH FOUNDATION, INC.

By:
   --------------------------------
Name:
Its:

      LB I GROUP, INC.

By: /s/ Fred Steinberg
   --------------------------------
Name: Fred Steinberg
     ------------------------------
Its: Vice President
    -------------------------------

                                     - 21 -
<PAGE>

By: /s/ [ILLEGIBLE]                         DESIGNATED SIGNATORY
   ---------------------------------            Pursuant to
Name:                                        Power of Attorney
     ------------------------------
Its:
    -------------------------------

      FREDERICK R. ADLER

      /s/ [ILLEGIBLE]                        DESIGNATED SIGNATORY
      -----------------------------              Pursuant to
                                              Power of Attorney

      2001 PARTNERS, L.P.

By: /s/ [ILLEGIBLE]                         DESIGNATED SIGNATORY
   ---------------------------------            Pursuant to
Name:                                        Power of Attorney
     ------------------------------
Its:
    -------------------------------

      SIPAREX PME

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      MICHEAL LEWIS, M.D.

     ------------------------------

      SIPAREX DEVELOPMENT

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      PHILIP R. CHAPMAN

                                     - 22 -
<PAGE>

      EURO-AMERICA II, L.P.

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      FREDERICK R. ADLER

      -----------------------------

      2001 PARTNERS, L.P.

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      SIPAREX PME

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      MICHEAL LEWIS, M.D.

     ------------------------------

      SIPAREX DEVELOPMENT

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 22 -
<PAGE>

      PHILIP R. CHAPMAN

      -----------------------------

      JACQUES VALLEE

      /s/ Jacques Vallee
      -----------------------------

      RTI ADVISORY GROUP, L.L.C.

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 23 -
<PAGE>

      PHILIP R. CHAPMAN

      -----------------------------

      JACQUES VALLEE

      -----------------------------

      RTI ADVISORY GROUP, L.L.C.

By: /s/ Kevin T. Foley, M.D.
   ---------------------------------
Name: Kevin T. Foley, M.D.
     ------------------------------
Its:
    -------------------------------

                                     - 23 -
<PAGE>

      /s/ [ILLEGIBLE]                        DESIGNATED SIGNATORY
      -----------------------------              Pursuant to
                                              Power of Attorney

      JACQUES VALLEE

     ------------------------------

      RTI ADVISORY GROUP, L.L.C.

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 23 -
<PAGE>

      PHILIP R. CHAPMAN

      /s/ Philip R. Chapman
      -----------------------------

      JACQUES VALLEE

     ------------------------------

      RTI ADVISORY GROUP, L.L.C.

By:
   ---------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 23 -
<PAGE>

CLASS B STOCKHOLDERS

      FREDERICK R. ADLER

      -----------------------------

      PHILIP R. CHAPMAN

      -----------------------------

      ADLER CHILDREN TRUST

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      EURO-AMERICA-II, L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB I GROUP INC.

By: /s/ Fred Steinberg
   --------------------------------
Name: Fred Steinberg
     ------------------------------
Its: Vice President
    -------------------------------

      LB MBG VC PARTNERS 1998 (A) L.P.

By: /s/ Fred Steinberg
   --------------------------------
Name: Fred Steinberg
     ------------------------------
Its: Vice President of LBI Group Inc.
    ---------------------------------
     Its General Partner

                                     - 24 -
<PAGE>

CLASS B STOCKHOLDERS

      FREDERICK R. ADLER

      /s/ [ILLEGIBLE]                  DESIGNATED SIGNATORY
      ------------------------------       Pursuant To
                                        Power of Attorney

      PHILIP R. CHAPMAN

      /s/ [ILLEGIBLE]                 DESIGNATED SIGNATORY
      ------------------------------      Pursuant To
                                       Power of Attorney

      ADLER CHILDREN TRUST

By: /s/ [ILLEGIBLE]                  DESIGNATED SIGNATORY
   --------------------------------      Pursuant To
Name:                                 Power of Attorney
     ------------------------------
Its:
    -------------------------------

      EURO-AMERICA-II, L.P.

By: /s/ [ILLEGIBLE]                  DESIGNATED SIGNATORY
   --------------------------------      Pursuant To
Name:                                 Power of Attorney
     ------------------------------
Its:
    -------------------------------

      LB I GROUP INC.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB MBG VC PARTNERS (A) L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB MBG VC PARTNERS (B) L.P.

                                     - 24 -
<PAGE>

CLASS B STOCKHOLDERS

      FREDERICK R. ADLER

      -----------------------------

      PHILIP R. CHAPMAN

      /s/ Philip R. Chapman
      -----------------------------

      ADLER CHILDREN TRUST

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      EURO-AMERICA-II, L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB I GROUP INC.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB MBG VC PARTNERS 1998 (A) L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 24 -
<PAGE>

      LB MBG VC PARTNERS 1998 (B) L.P.

By: /s/ Fred Steinberg
   --------------------------------
Name: Fred Steinberg
     ------------------------------
Its: Vice President of LB I Group Inc.
    ---------------------------------
     Its General Partner

      LB MGB VC PARTNERS 1998 (C) L.P.

By: /s/ Fred Steinberg
   --------------------------------
Name: Fred Steinberg
     ------------------------------
Its: Vice President of LB I Group Inc.
    ---------------------------------
     Its General Partner

      LB MGB VC PARTNERS 1998 (D) L.P.

By: /s/ Fred Steinberg
   --------------------------------
Name: Fred Steinberg
     ------------------------------
Its: Vice President of LB I Group Inc.
    ---------------------------------
     Its General Partner

      MICHAEL LEWIS, M.D.

      -----------------------------

      2001 PARTNERS, L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 25 -
<PAGE>

      LB MBG VC PARTNERS (B) L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB MGB VC PARTNERS (C) L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB MGB VC PARTNERS (D) L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      MICHAEL LEWIS, M.D.

      -----------------------------

      2001 PARTNERS, L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 25 -
<PAGE>

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB MGB VC PARTNERS (C) L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      LB MGB VC PARTNERS (D) L.P.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      MICHAEL LEWIS, M.D.

      -----------------------------

      2001 PARTNERS, L.P.

By: /s/ [ILLEGIBLE]                  DESIGNATED SIGNATORY
   --------------------------------      Pursuant To
Name:                                 Power of Attorney
     ------------------------------
Its:
    -------------------------------

                                     - 25 -
<PAGE>

      SIPAREX PME

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      SIPAREX DEVELOPMENT

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      JACQUES VALLEE

      /s/ Jacques Vallee
      -----------------------------

      RTI ADVISORY GROUP, L.L.C.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

CLASS C STOCKHOLDERS

      MEDTRONIC ASSET MANAGEMENT, INC.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

     ------------------------------

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 26 -
<PAGE>

      SIPAREX PME

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      SIPAREX DEVELOPMENT

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      JACQUES VALLEE

      -----------------------------

      RTI ADVISORY GROUP, L.L.C.

By: /s/ Kevin T. Foley, M.D.
   --------------------------------
Name: Kevin T. Foley, M.D.
     ------------------------------
Its:
    -------------------------------

CLASS C STOCKHOLDERS

      MEDTRONIC ASSET MANAGEMENT, INC.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

     ------------------------------

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 26 -
<PAGE>

      SIPAREX PME

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      SIPAREX DEVELOPMENT

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      JACQUES VALLEE

      -----------------------------

      RTI ADVISORY GROUP, L.L.C.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

CLASS C STOCKHOLDERS

      MEDTRONIC ASSET MANAGEMENT, INC.

By: /s/ Michael D. Ellwein
   --------------------------------
Name: Michael D. Ellwein
     ------------------------------
Its: Vice President and Chief Development Officer
    -------------------------------

     STEPHENS-REGENERATION LLC

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

                                     - 27 -
<PAGE>

      SIPAREX PME

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      SIPAREX DEVELOPMENT

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

      JACQUES VALLEE

      -----------------------------

      RTI ADVISORY GROUP, L.L.C.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

CLASS C STOCKHOLDERS

      MEDTRONIC ASSET MANAGEMENT, INC.

By:
   --------------------------------
Name:
     ------------------------------
Its:
    -------------------------------

     STEPHENS-REGENERATION LLC

By: /s/ Jackson Farrow, Jr.
   --------------------------------
Name: Jackson Farrow Jr.
Its: Vice-President of Stephens Group, Inc., its manager

                                     - 27 -
<PAGE>

                                    EXHIBIT A

Class B Investors:

Frederick R. Adler
C/O Jay Nickse
Venad Administrative Services, Inc.
Suite 807, 342 Madison Avenue
New York, NY 10173

Philip R. Chapman
Suite 807, 342 Madison Avenue
New York, NY 10173

Adler Children Trust
C/O Jay Nickse
Venad Administrative Services, Inc.
Suite 807, 342 Madison Avenue
New York, NY 10173

Euro-America-LI, L.P.
C/O Jay Nickse
Venad Administrative Services, Inc.
Suite 807, 342 Madison Avenue
New York, NY 10173

LB I Group Inc.
Attn: Fred E. Steinberg, Vice President
Lehman Brothers, Inc.
3 World Financial Center--8th Floor
New York, NY 10285-0800

LB MBG VC Partners (A) L.P.
Attn: Fred E. Steinberg, Vice President
Lehman Brothers, Inc.
3 World Financial Center--8th Floor
New York, NY 10285-0800
<PAGE>

LB MBG VC Partners (B) L.P.
Attn: Fred E. Steinberg, Vice President
Lehman Brothers, Inc.
3 World Financial Center--8th Floor
New York, NY 10285-0800

LB MBG VC Partners (C) L.P.
Attn: Fred E. Steinberg, Vice President
Lehman Brothers, Inc.
3 World Financial Center--8th Floor
New York, NY 10285-0800

LB MBG VC Partners (D) L.P.
Attn: Fred E. Steinberg, Vice President
Lehman Brothers, Inc.
3 World Financial Center--8th Floor
New York, NY 10285-0800

Michael Lewis, M.D.
Goldman, Sachs & Co.
Attn: IRA Department
10 Hanover Square
11th Floor
New York, NY 10005

2001 Partners, L.P.
C/O Jay Nickse
Venad Administrative Services, Inc.
Suite 807, 342 Madison Avenue
New York, NY 10173

Siparex PME
Attention: J. F. Puech
139, Rue Vendome
69477 Lyon - Cedex 06
FRANCE

                                     - 2 -
<PAGE>

Siparex Development
Attention: J. F. Puech
139, Rue Vendome
69477 Lyon - Cedex 06
FRANCE

Jacques Vallee
1835 Franklin Street
#1501
San Francisco, CA 94109

RTI Advisory Group L.L.C.
C/O Robert Hyde
530 Oak Court Drive, Suite 345
Memphis, TN 38117

                                     - 3 -
<PAGE>

                                    EXHIBIT B

Class A Investors:

James M. Grooms
One Innovation Drive
Alachua, FL 32615

University of Florida Tissue Bank
One Innovation Drive
Alachua, FL 32615

University of Florida Research Foundation, Inc.
Attn: General Counsel
P.O. Box 100215
Gainesville, FL 32610

LB I Group, Inc.
Attn: Fred E. Steinberg, Vice President
Lehman Brothers, Inc.
3 World Financial Center --8th Floor
New York, NY 10285-0800

Euro-America II, L.P.
C/O Jay Nickse
Venad Administrative Services, Inc.
Suite 807, 342 Madison Avenue
New York, NY 10173

Frederick R. Adler
C/O Jay Nickse
Venad Administrative Services, Inc.
Suite 807, 342 Madison Avenue
New York, NY 10173

2001 Partners, L.P.
C/O Jay Nickse
Venad Administrative Services, Inc.
Suite 807, 342 Madison Avenue
New York, NY 10173
<PAGE>

Siparex PME
Attention: J. F. Puech
139, Rue Vendome
69477 Lyon - Cedex 06
FRANCE

Michael Lewis, M.D.
Goldman, Sachs & Co.
Attn: IRA Department
10 Hanover Square
11th Floor
New York, NY 10005

Siparex Development
Attention: J. F. Puech
139, Rue Vendome
69477 Lyon - Cedex 06
FRANCE

Philip R. Chapman
Suite 807, 342 Madison Avenue
New York, NY 10173

Jacques Vallee
1835 Franklin Street
#1501
San Francisco, CA 94109

RTI Advisory Group, L.L.C.
C/O Robert Hyde
530 Oak Court Drive, Suite 345
Memphis, TN 38117

                                     - 2 -

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