<PAGE>
                                                                               .
                                                                               .
                                                                               .

                                                                   EXHIBIT 10.25

                                 PROMISSORY NOTE

<TABLE>
<CAPTION>
PRINCIPAL         LOAN DATE         MATURITY      LOAN NO    CALL          COLLATERAL      ACCOUNT            OFFICER    INITIAL
<S>               <C>               <C>           <C>        <C>           <C>             <C>                <C>        <C>
$720,000.00        05-22-2001
</TABLE>

    References in the shaded area are for Lender's use only and do not limit
        the applicability of this document to any particular loan or item.

<TABLE>
<S>                                                    <C>
BORROWER: CELL & MOLECULAR TECHNOLOGIES, INC. (TIN:    LENDER:   PNC BANK, NATIONAL ASSOCIATION
          223512377)                                             201 PENN AVENUE
          580 MARSHALL STREET                                    SCRANTON, PA 18503
          PHILLIPSBURG, NJ 08865
</TABLE>

<TABLE>
<S>                                   <C>                          <C>
PRINCIPAL AMOUNT:  $720,000.00        INITIAL RATE:  7.500%        DATE OF NOTE:  MAY 22, 2001
</TABLE>

PROMISE TO PAY. CELL & MOLECULAR TECHNOLOGIES, INC. ("BORROWER") PROMISES TO PAY
TO PNC BANK, NATIONAL ASSOCIATION ("LENDER"), OR ORDER, IN LAWFUL MONEY OF THE
UNTIED STALES OF AMERICA, THE PRINCIPAL AMOUNT OF SEVEN HUNDRED TWENTY THOUSAND
& 00/100 DOLLARS ($720,000,00) OR SO MUCH AS MAY BE OUTSTANDING, TOGETHER WITH
INTEREST ON THE UNPAID PRINCIPAL BALANCE FROM MAY 23, 2001, UNTIL PAID IN FULL.

PAYMENT. SUBJECT TO ANY PAYMENT CHANGES RESULTING FROM CHANGES IN THE INDEX,
BORROWER WILL PAY THIS LOAN IN ACCORDANCE WITH THE FOLLOWING PAYMENT SCHEDULE:

         PRIOR TO MAY 22, 2002 (THE "CONVERSION DATE"), INTEREST ONLY SHALL BE
         DUE AND PAYABLE COMMENCING JUNE 22, 2001 AND CONTINUING ON THE SAME DAY
         OF EACH MONTH THEREAFTER UNTIL THE CONVERSION DATE, WITH INTEREST
         CALCULATED ON THE UNPAID PRINCIPAL BALANCE AT A RATE EQUAL TO THE INDEX
         (AS DEFINED BELOW). FROM AND AFTER THE CONVERSION DATE, PRINCIPAL AND
         INTEREST WILL BE PAYABLE AS FOLLOWS: (I) COMMENCING ON JUNE 22, 2002,
         AND CONTINUING ON THE SAME DAY OF EACH MONTH THEREAFTER TO AND
         INCLUDING APRIL 22, 2009, PAYMENTS OF PRINCIPAL TOGETHER WITH INTEREST
         CALCULATED ON THE UNPAID BALANCE OF THIS NOTE AT THE AS OFFERED
         INTEREST RATE (AS HEREINAFTER DEFINED) IN EFFECT ON THE CONVERSION DATE
         IN AN AMOUNT (THE "LEVEL PAYMENT AMOUNT") SUFFICIENT TO AMORTIZE THE
         OUTSTANDING PRINCIPAL BALANCE OF THIS NOTE ON THE CONVERSION DATE, ON A
         MORTGAGE STYLE AMORTIZATION SCHEDULE, OVER A SEVEN (7) YEAR TERM; AND
         (II) A FINAL PAYMENT ON MAY 22,2009 (THE "MATURITY DATE") EQUAL TO ALL
         PRINCIPAL, ACCRUED AND UNPAID INTEREST, AND OTHER CHARGES THEN UNPAID.
         THE "AS-OFFERED INTEREST RATE" SHALL MEAN A RATE OF INTEREST PER ANNUM,
         AS OFFERED BY LENDER TO THE BORROWER IN ITS SOLE DISCRETION, AS THE
         RATE AT WHICH LENDER WOULD ADVANCE FUNDS TO THE BORROWER FOR THE THEN
         REMAINING TERM OF THIS NOTE IN THE PRINCIPAL AMOUNT OF THIS NOTE THEN
         OUTSTANDING. THE AS-OFFERED INTEREST RATE SHALL BE AGREED TO BY THE
         BORROWER AND LENDER NO LATER THAN THIRTY (30) DAYS PRIOR TO THE
         CONVERSION DATE. IF THE BORROWER AND LENDER CANNOT AGREE UPON AN
         AS-OFFERED INTEREST RATE AT LEAST THIRTY (30) DAYS PRIOR TO THE
         CONVERSION DATE, INTEREST WILL ACCRUE ON THIS NOTE FOLLOWING THE
         CONVERSION DATE AT A RATE (THE "BASE RATE") EQUAL TO THE INDEX (AS
         DEFINED HEREIN) AND THE BASE RATE SHALL BE SUBSTITUTED FOR THE
         AS-OFFERED RATE IN DETERMINING THE LEVEL PAYMENT AMOUNT. IF THE LEVEL
         PAYMENT AMOUNT IS CALCULATED USING THE BASE RATE, SUCH LEVEL PAYMENT
         AMOUNT MAY BE ADJUSTED UPWARD FROM TIME TO TIME BY LENDER IN ITS
         DISCRETION IF: (a) BECAUSE OF CHANGES IN THE INDEX, THE LEVEL PAYMENT
         AMOUNT BECOMES INSUFFICIENT TO REPAY ALL ACCRUED INTEREST FOR ANY
         PAYMENT PERIOD; OR (b) ANY PAYMENT(S) ARE MADE BY BORROWER AFTER THEIR
         RESPECTIVE DUE DATE(S). OTHERWISE ANY LEVEL PAYMENT AMOUNT MAY BE
         ADJUSTED (UPWARD OR DOWNWARD) BY LENDER AS OF JANUARY 1ST OF EACH YEAR
         TO REFLECT CHANGES IN THE APPLICABLE INTEREST RATE. THE LEVEL PAYMENT
         AMOUNT AS ADJUSTED BY LENDER FROM TIME TO TIME SHALL, AT THE TIME OF
         SUCH ADJUSTMENT, BE IN AN AMOUNT SUFFICIENT TO FULLY AMORTIZE THE THEN
         OUTSTANDING BALANCE OF THIS NOTE BASED ON THE THEN REMAINING TERM OF
         THIS NOTE. THE "INDEX" SHALL MEAN THE RATE PUBLICLY ANNOUNCED BY LENDER
         FROM TIME TO TIME AS ITS PRIME RATE. THE PRIME RATE IS NOT TIED TO ANY
         EXTERNAL RATE OR INDEX AND DOES NOT NECESSARILY REFLECT THE LOWEST RATE
         OF INTEREST ACTUALLY CHARGED BY LENDER TO ANY PARTICULAR CLASS OR
         CATEGORY OF CUSTOMERS. IF AND WHEN THE PRIME RATE CHANGES, THE INDEX
         WILL CHANGE AUTOMATICALLY WITHOUT NOTICE TO THE BORROWER, EFFECTIVE ON
         THE DATE OF ANY SUCH CHANGE. UNDER NO CIRCUMSTANCES WILL THE INTEREST
         RATE ON THIS NOTE BE MORE THAN THE MAXIMUM RATE ALLOWED BY APPLICABLE
         LAW.

The annual interest rate for this Note is computed on a 365/360 basis; that is,
by applying the ratio of the annual interest rate over a year of 360 days,
multiplied by the outstanding principal balance, multiplied by the actual number
of days the principal balance is outstanding. Borrower will pay Lender at
Lender's address shown above or at such other place as Lender may designate in
writing. Unless otherwise agreed or required by applicable law, payments will be
applied first to accrued unpaid interest, then to principal, and any remaining
amount to any unpaid collection costs and late charges.

VARIABLE INTEREST RATE. The interest rate on this Note is subject to change from
time to time based on changes in an index which is the Lender's Prime Rate (the
"Index"). The index is a rate per annum as publicly announced by Lender from
time to time as its Prime Rate. The Prime Rate is not tied to any external rate
or index and it does not necessarily reflect the lowest rate of interest
actually charged by Lender to any particular class or category of customers.
Lender will tell Borrower the current Index rate upon Borrower's request.
Borrower understands that Lender may make loans based on other rates as well.
The interest rate change will not occur more often than each day. THE INDEX
CURRENTLY IS 7.000% PER ANNUM. THE INTEREST RATE TO BE APPLIED TO THE UNPAID
PRINCIPAL BALANCE OF THIS NOTE WILL BE AT A RATE OF 0.500 PERCENTAGE POINTS OVER
THE INDEX, RESULTING IN A CURRENT RATE OF 7.500% PER ANNUM. NOTICE: Under no
circumstances will the interest rate on this Note be more than the maximum rate
allowed by applicable law. Whenever increases occur in the interest rate,
Lender, at its option, may do one or more of the following: (a) increase
Borrower's payments to ensure Borrower's loan will pay off by its original final
maturity date, (b) increase Borrower's payments to cover accruing interest, (c)
increase the number of Borrower's payments, and (d) continue Borrower's payments
at the same amount and increase Borrower's final payment.

PREPAYMENT PENALTY. UPON PREPAYMENT OF THIS NOTE, LENDER IS ENTITLED TO THE
FOLLOWING PREPAYMENT PENALTY: UPON PREPAYMENT OF THIS NOTE, LENDER IS ENTITLED
TO THE FOLLOWING PREPAYMENT PENALTY: ON ANY BUSINESS DAY, UPON PAYMENT OF ALL
ACCRUED UNPAID INTEREST ON THE NOTE, AND UPON FIVE (5) BUSINESS DAY'S PRIOR
WRITTEN NOTICE TO LENDER, THE BORROWER MAY PREPAY ALL OR PART OF THE OUTSTANDING
PRINCIPAL HEREUNDER; PROVIDED, HOWEVER, THAT IF THE PREPAYMENT IS MADE DURING
THE FIXED RATE PERIOD, THE BORROWER, WHERE NOT PROHIBITED BY LAW, ALSO AGREES TO
PAY LENDER AS COMPENSATION FOR THE COST OF BEING PREPARED TO ADVANCE FIXED RATE
FUNDS HEREUNDER AN AMOUNT EQUAL TO THE COST OF PREPAYMENT. "COST OF PREPAYMENT"
MEANS AN AMOUNT EQUAL TO THE PRESENT VALUE, IF POSITIVE, OF THE PRODUCT OF (a)
THE DIFFERENCE BETWEEN (I) THE YIELD, ON THE BEGINNING DATE OF THE APPLICABLE
INTEREST PERIOD, OF A U.S. TREASURY OBLIGATION WITH A MATURITY SIMILAR TO THE
APPLICABLE INTEREST PERIOD MINUS (II) THE YIELD ON THE PREPAYMENT DATE, OF A
U.S. TREASURY OBLIGATION WITH A MATURITY SIMILAR TO THE REMAINING MATURITY OF
THE APPLICABLE INTEREST PERIOD, AND (b) THE PRINCIPAL AMOUNT TO BE PREPAID, AND
(c) THE NUMBER OF YEARS, INCLUDING FRACTIONAL YEARS, FROM THE PREPAYMENT DATE TO
THE END OF THE APPLICABLE INTEREST PERIOD. THE YIELD ON ANY U.S. TREASURY
OBLIGATION SHALL BE DETERMINED BY REFERENCE TO FEDERAL RESERVE STATISTICAL
RELEASE H.15 (519) "SELECTED INTEREST RATES". FOR PURPOSES OF MAKING PRESENT
VALUE CALCULATIONS, THE YIELD TO MATURITY OF A SIMILAR MATURITY U.S. TREASURY
OBLIGATION ON THE PREPAYMENT DATE SHALL BE DEEMED THE DISCOUNT RATE. THE COST OF
PREPAYMENT SHALL ALSO APPLY TO ANY PAYMENTS MADE AFTER ACCELERATION OF THE
MATURITY OF THIS NOTE WHILE A FIXED RATE IS IN EFFECT. Except for the foregoing,
Borrower may pay all or a portion of the amount owed earlier than it is due.
Early payments will not, unless agreed to by Lender in writing, relieve Borrower
of Borrower's obligation to continue to make payments under the payment
schedule. Rather, they will reduce the principal balance due and may result in
Borrower making fewer payments.

LATE CHARGE. If a payment is 15 DAYS OR MORE LATE, Borrower will be charged
5.000% of the unpaid portion of the regularly scheduled payment

<PAGE>

05-22-2001                      PROMISSORY NOTE                           PAGE 2
LOAN NO                           (CONTINUED)

OR $2.50, WHICHEVER IS GREATER.

DEFAULT. Borrower will be in default if any of the following happens: (a)
Borrower fails to make any payment when due. (b) Borrower breaks any promise
Borrower has made to Lender, or Borrower fails to comply with or to perform when
due any other term, obligation, covenant, or condition contained in this Note or
any agreement related to this Note, or in any other agreement or loan Borrower
has with Lender, (c) Any representation statement made or furnished to Lender by
Borrower or on Borrower's behalf is false or misleading in any material respect
either now or at the [ILLEGIBLE] made or Furnished, (d) Borrower becomes
insolvent, a receiver is appointed for any part of Borrower's property, Borrower
makes an assignment for the benefit of creditors, or any proceeding is commenced
either by Borrower or against Borrower under any bankruptcy Of insolvency laws.
(e) Any creditor tries to take any of Borrower's property on or in which Lender
has a lien or security interest. This includes a garnishment of any of
Borrower's accounts with Lender, (f) Any guarantor dies or any of the other
events described in this default section occurs with respect to any guarantor of
this Note. (g) A material adverse change occurs in Borrower's financial
condition, or Lender believes !he prospect of payment or performance of the
Indebtedness is impaired.

LENDER'S RIGHTS. Upon default, Lender may, after giving such notices as required
by applicable law, declare the entire unpaid principal balance on this Note and
all accrued unpaid interest immediately due, and then Borrower will pay that
amount. Upon default, including failure to pay upon final maturity, Lender, at
its option, may also, if permitted under applicable law, increase the variable
interest rate on this Note to 5,500 percentage points OVER the Index. The
interest rate will not exceed the maximum rate permitted by applicable law.
Lender may hire or pay someone else to help collect this Note if Borrower does
not pay. Borrower also will pay Lender that amount. This includes, subject to
any limits under applicable law, Lender's attorneys' fees and Lender's legal
expenses whether or not there is a lawsuit, including attorneys' fees and legal
expenses for bankruptcy proceedings (Including efforts to modify or vacate any
automatic stay or injunction), appeals, and any anticipated post-judgment
collection services. If not prohibited by applicable law, Borrower also will pay
any court costs, in addition to all other sums provided by law. If judgment is
entered in connection with this Note, interest will continue to accrue on this
Note after judgment at the interest rate applicable to this Note at the time
judgment is entered. THIS NOTE HAS BEEN DELIVERED TO LENDER END ACCEPTED BY
LENDER IN THE COMMONWEALTH OF PENNSYLVANIA. IF THERE IS A LAWSUIT, BORROWER
AGREES UPON LENDER'S REQUEST TO SUBMIT TO THE JURISDICTION OF THE COURTS OF
LACKAWANNA COUNTY, THE COMMONWEALTH OF PENNSYLVANIA. LENDER AND BORROWER HEREBY
WAIVE THE RIGHT TO ANY JURY TRIAL IN ANY ACTION, PROCEEDING, OR COUNTERCLAIM
BROUGHT BY EITHER LENDER OR BORROWER AGAINST THE OTHER. THIS NOTE SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE COMMONWEALTH OF
PENNSYLVANIA.

RIGHT OF SETOFF. Borrower grants to Lender a contractual security interest in,
and hereby assigns, conveys, delivers, pledges, and transfers to Lender all
Borrower's right, title and interest in and to. Borrower's accounts with Lender
(whether checking, savings, or some other account), including without limitation
all accounts held jointly with someone else and all accounts Borrower may open
in the future, excluding however all IRA and Keogh accounts, and all trust
accounts for which the grant of a security interest would be prohibited by law.
Borrower authorizes Lender, to the extent permitted by applicable law, to charge
or setoff all sums owing on this Note against any and all such accounts.

FINANCIAL INFORMATION PROVISION. Borrower agrees to deliver any financial and
other business information concerning Borrower that Lender may request from time
to time, such as annual and interim financial statements (all of which shall be
prepared in accordance with generally accepted accounting principles) and
federal income tax returns.

YEAR 2000 COMPLIANCE. Borrower has reviewed the areas within its business and
operations which could be adversely affected by, and has developed or is
developing a program to address on a timely basis the risk that certain computer
applications used by Borrower may be unable to recognize and perform properly
date-sensitive functions involving dates prior to and after December 31, 1999
(the "Year 2000 Problem"). The Year 2000 Problem will not result, and is not
reasonably expected to result, in any material adverse effect on the business,
properties, assets, financial condition, results of operations or prospects of
Borrower, or the ability of Borrower to duly and punctually pay or perform its
obligations hereunder. [ILLEGIBLE] under the Related Documents.

CURE OF DEFAULT. The provisions of this Note entitled "Default" are hereby
modified as follows: (i) in the case of a default specified in clause (a),
Borrower shall have ten (10) days to cure such default; (ii) in the case of a
default specified in clauses (b), (c) or (g), the Borrower shall have thirty
(30) days following written notice of such default from Lender to cure such
default by remedying, discharging, removing or otherwise obviating the cause
thereof; and (iii) in the case of a default specified in clause (e) because of
the commencement of an involuntary proceeding against Borrower under any
bankruptcy laws, a default shall result only if such proceeding is not dismissed
or stayed within forty-five (45) days of the commencement thereof,

MODIFICATION OF CONFESSION OF JUDGMENT. Notwithstanding the attorney's
commission provided for in the paragraph of this Note entitled "Confession of
Judgment" (which is included in the warrant for purposes of establishing a sum
certain), the amount of attorneys' fees that Lender may recover from Borrower
shall not exceed the actual attorneys' fees incurred by Lender.

LINE OF CREDIT. This Note evidences a straight line of credit. Once the total
amount of principal has been advanced, Borrower is not entitled to further loan
advances. Advances under this Note may be requested orally by Borrower or by an
authorized person. Lender may, but need not, require that all oral requests be
confirmed in writing. All communications, instructions, or directions by
telephone or otherwise to Lender are to be directed to Lender's office shown
above. Borrower agrees to be liable for all sums either: (a) advanced in
accordance with the instructions of an authorized person or (b) credited to any
of Borrower's accounts with Lender. The unpaid principal balance owing on this
Note at any time may be evidenced by endorsements on this Note or by Lender's
internal records, including daily computer print-outs. Lender will have no
obligation to advance funds under this Note if: (a) Borrower or any guarantor is
in default under the terms of this Note or any agreement that Borrower or any
guarantor has with Lender, including any agreement made in connection with the
signing of this Note; (b) Borrower or any guarantor ceases doing business or is
insolvent; (c) any guarantor seeks, claims or otherwise attempts to limit,
modify or revoke such guarantee of this Note or any other loan with Lender; or
(d) Borrower has applied funds provided pursuant to this Note for purposes other
than those authorized by Lender.

GENERAL PROVISIONS. Lender may delay or forgo enforcing any of its rights or
remedies under this Note without losing them. Borrower and any other person who
signs, guarantees or endorses this Note, to the extent allowed by law, waive
presentment, demand for payment, protest and notice of dishonor. Upon any change
in the terms of this Note, and unless otherwise expressly stated in writing, no
party who signs this Note, whether as maker, guarantor, accommodation maker or
endorser, shall be released from liability. All such parties agree that Lender
may renew or extend (repeatedly and for any length of time) this loan, or
release any party or guarantor or collateral; or impair, fail to realize upon or
perfect Lender's security interest in the collateral; and take any other action
deemed necessary by Lender without the consent of or notice to anyone. All such
parties also agree that Lender may modify this loan without the consent of or
notice to anyone other than the party with whom the modification is made. If any
portion of this Note is for any reason determined to be unenforceable, it will
not affect the enforceability of any other provisions of this Note.

CONFESSION OF JUDGMENT. BORROWER HEREBY IRREVOCABLY AUTHORIZES AND EMPOWERS ANY
ATTORNEY OR THE PROTHONOTARY OR CLERK OF ANY COURT IN THE COMMONWEALTH OF
PENNSYLVANIA, OR ELSEWHERE, TO APPEAR AT ANY TIME FOR BORROWER AFTER A DEFAULT
UNDER THIS NOTE, AND WITH OR WITHOUT COMPLAINT FILED, AS OF ANY TERM, CONFESS OR
ENTER JUDGMENT AGAINST BORROWER FOR THE ENTIRE PRINCIPAL BALANCE OF THIS NOTE,
ALL ACCRUED INTEREST, LATE CHARGES, AND ANY AND ALL AMOUNT EXPENDED OR ADVANCED
BY LENDER RELATING TO ANY COLLATERAL SECURING THIS NOTE TOGETHER WITH INTEREST
ON SUCH AMOUNTS, TOGETHER WITH COSTS OF SUIT, AND AN ATTORNEY'S COMMISSION OF
TEN PERCENT (10%) OF THE UNPAID PRINCIPAL BALANCE AND ACCRUED INTEREST FOR
COLLECTION, BUT IN ANY EVENT NOT LESS THAN FIVE HUNDRED DOLLARS ($500) ON WHICH
JUDGMENT OR JUDGMENTS ONE OR MORE EXECUTIONS MAY ISSUE IMMEDIATELY; AND FOR SO
DOING, THIS NOTE OR A COPY OF THIS NOTE VERIFIED BY AFFIDAVIT SHALL BE
SUFFICIENT WARRANT. THE AUTHORITY GRANTED IN THIS NOTE TO CONFESS JUDGMENT
AGAINST BORROWER SHALL NOT BE EXHAUSTED BY ANY EXERCISE OF THAT AUTHORITY, BUT
SHALL CONTINUE FROM TIME TO TIME AND

<PAGE>

05-22-2001                      PROMISSORY NOTE                           PAGE 3
LOAN NO                           (CONTINUED)

AT ALL TIMES UNTIL PAYMENT IN FULL OF ALL AMOUNTS DUE UNDER THIS NOTE. BORROWER
HEREBY WAIVES ANY RIGHT BORROWER MAY HAVE TO NOTICE OR TO A HEARING IN
CONNECTION WITH ANY SUCH CONFESSION OF JUDGMENT, EXCEPT ANY NOTICE AND/OR
HEARING REQUIRED UNDER APPLICABLE LAW WITH RESPECT TO EXECUTION OF THE JUDGMENT,
AND STATES THAT EITHER A REPRESENTATIVE OF LENDER SPECIFICALLY CALLED THIS
CONFESSION OF JUDGMENT PROVISION TO BORROWER'S ATTENTION OR BORROWER HAS BEEN
REPRESENTED BY INDEPENDENT LEGAL COUNSEL.

PRIOR TO SIGNING THIS NOTE, BORROWER READ AND UNDERSTOOD ALL THE PROVISIONS OF
THIS NOTE, INCLUDING THE VARIABLE INTEREST RATE PROVISIONS. BORROWER AGREES TO
THE TERMS OF THE NOTE AND ACKNOWLEDGES RECEIPT OF A COMPLETED COPY OF THE NOTE.

THIS NOTE HAS BEEN SIGNED AND SEALED BY THE UNDERSIGNED.

BORROWER:

CELL & MOLECULAR TECHNOLOGIES, INC.

By: /s/ Fredrick B. Rolff,     (SEAL)
   -----------------------------
    FREDRICK B. ROLFF, CFO

 Variable Rate, Generic.        LASER PRO, Reg. U.S. Pat. a T.M. Off., Ver. 3.29
                                a(C) Concentrex 2001 All rights reserved.
                                [PA-D20 E3.29CELL MOL 1 LN C78.OVL]

<PAGE>

                    CORPORATE RESOLUTION TO GRANT COLLATERAL

<TABLE>
<CAPTION>

PRINCIPAL     LOAN DATE          MATURITY    LOAN NO          CALL     COLLATERAL         ACCOUNT        OFFICER   INITIALS
<S>           <C>                <C>         <C>              <C>      <C>                <C>            <C>       <C>
$720,000.00   05-23-2001                                                                                  69602
</TABLE>

  References In the shaded area are for Lender's use only and do not limit the
         applicability of this document to any particular loan or item.

<TABLE>
<S>                                                        <C>
BORROWER:   CELL & MOLECULAR TECHNOLOGIES, INC. (TIN:      LENDER:   PNC BANK, NATIONAL ASSOCIATION
            223512377}                                               201 PENN AVENUE
            580 MARSHALL STREET                                      SCRANTON, PA 18503
            PHILLIPSBURG, NJ 08865
GRANTOR:    CELL & MOLECULAR TECHNOLOGIES, INC.
            580 MARSHALL STREET
            PHILLIPSBURG, PA 08865
</TABLE>

I, THE UNDERSIGNED SECRETARY OR ASSISTANT SECRETARY OF CELL & MOLECULAR
TECHNOLOGIES, INC. (THE "CORPORATION"), HEREBY CERTIFY THAT the Corporation is
organized and existing under and by virtue of the laws of the Commonwealth of
Pennsylvania with its principal office at 580 MARSHALL STREET, PHILLIPSBURG, PA
08865.

I FURTHER CERTIFY that at a meeting of the Directors of the Corporation, duly
called and held on 5/29/01, at which a quorum was present and voting, or by
other duly authorized corporate action in lieu of a meeting, the following
resolutions were adopted:

BE IT RESOLVED, that any one (1) of the following named officers, employees, or
agents of this Corporation, whose actual signatures are shown below:

<TABLE>
<CAPTION>
NAME                                     POSITION                                ACTUAL SIGNATURE
----                                     --------                                ----------------
<S>                                      <C>                                     <C>
FREDRICK B. ROLFF                           CFO                                   /s/ Fredrick B. Rolff
                                                                                      ------------------
                                                                                      Fredrick B. Rolff
</TABLE>

acting for and on behalf of the Corporation and as its act and deed be, and he
or she hereby is, authorized and empowered:

         GRANT SECURITY, To mortgage, pledge, transfer, endorse, hypothecate, or
         otherwise encumber and deliver to PNC BANK, NATIONAL ASSOCIATION
         ("Lender"), as security for the payment of any loans, any promissory
         notes, or any other or further indebtedness of CELL & MOLECULAR
         TECHNOLOGIES, INC. to Lender at any time owing, however the same may be
         evidenced, any property now or hereafter belonging to the Corporation
         or in which the Corporation now or hereafter may have an interest,
         including without limitation all real property and all personal
         property (tangible or intangible) of the Corporation. Such property may
         be mortgaged, pledged, transferred, endorsed, hypothecated, or
         encumbered at the time such loans are obtained or such indebtedness is
         incurred, or at any other time or times, and may be either in addition
         to or in lieu of any property theretofore mortgaged, pledged,
         transferred, endorsed, hypothecated, or encumbered. The provisions of
         these Resolutions authorizing or relating to the pledge, mortgage,
         transfer, endorsement, hypothecation, granting of a security interest
         in, or in any way encumbering, the assets of the Corporation shall
         include, without limitation, doing so in order to lend collateral
         security for the indebtedness, now or hereafter existing, and of any
         nature whatsoever, of CELL & MOLECULAR TECHNOLOGIES, INC. to Lender.
         The Corporation has considered the value to itself of lending
         collateral in support of such indebtedness, and the Corporation
         represents to Lender that the Corporation is benefited by doing so.

         EXECUTE SECURITY DOCUMENTS. To execute and deliver to Lender the forms
         of mortgage, deed of trust, pledge agreement, hypothecation agreement,
         and other security agreements and financing statements which may be
         submitted by Lender, and which shall evidence the terms and conditions
         under and pursuant to which such liens and encumbrances, or any of
         them, are given; and also to execute and deliver to Lender any other
         written instruments, any chattel paper, or any other collateral, of any
         kind or nature, which he or she may in his or her discretion deem
         reasonably necessary or proper in connection with or pertaining to the
         giving of the liens and encumbrances.

         FURTHER ACTS. To do and perform such other acts and things and to
         execute and deliver such other documents and agreements, including
         agreements waiving the right to a trial by jury and confessing judgment
         against the Corporation, as he or she may in his or her discretion deem
         reasonably necessary or proper in order to carry into effect the
         provisions of these Resolutions.

BE IT FURTHER RESOLVED, that the Corporation will notify Lender in writing at
Lender's address shown above (or such other addresses as Lender may designate
from time to time) prior to any (a) change in the name of the Corporation, (b)
change in the assumed business name(s) of the Corporation, (c) change in the
management of the Corporation, (d) change in the authorized signer(s), (e)
conversion of the Corporation to a new or different type of business entity, or
(f) change in any other aspect of the Corporation that directly or indirectly
relates to any agreements between the Corporation and Lender. No change in the
name of the Corporation will take effect until after Lender has been notified.

BE IT FURTHER RESOLVED, that any and all acts authorized pursuant to these
Resolutions and performed prior to the passage of these Resolutions are hereby
ratified and approved, that these Resolutions shall remain in full force and
effect and Lender may rely on these Resolutions until written notice of his or
her revocation shall have been delivered to and received by Lender. Any such
notice shall not affect any of the Corporation's agreements or commitments in
effect at the time notice is given.

I FURTHER CERTIFY that the officer, employee, or agent named above is duly
elected, appointed, or employed by or for the Corporation, as the case may be,
and occupies the position set opposite the name; that the foregoing Resolutions
now stand of record on the books of the Corporation; and that the Resolutions
are in full force and effect and have not been modified or revoked in any manner
whatsoever.

<PAGE>

IN TESTIMONY WHEREOF, I HAVE HEREUNTO SET MY HAND AND SEAL ON MAY 23,2001 AND
ATTEST THAT THE SIGNATURES SET OPPOSITE THE NAMES LISTED . ABOVE ARE THEIR
GENUINE SIGNATURES.

                                              CERTIFIED TO AND ATTESTED BY:

                                              /s/ Thomas J. Livelli   (SEAL)

                                              /s/                     (SEAl)
                                              ______________________________

NOTE: In case the Secretary or other certifying officer is designated by the
foregoing resolutions as one of the signing officers, it is advisable to have
this certificate signed by a second Officer or Director of the Corporation.

LASER PRO, Reg. U.S. Pat. & T.M. Off., Ver. 3,29a (C) Concentrex 2001 All rights
reserved. [PA-C10C E3.29 F3.29 CELL MOLE. LN C68.OVL]

<PAGE>

                               COMMERCIAL GUARANTY
<TABLE>
<CAPTION>
PRINCIPAL          LOAN DATE        MATURITY      LOAN NO         CALL      COLLETERAL     ACCOUNT    OFFICER  INITIAL
<S>                <C>              <C>           <C>             <C>       <C>            <C>        <C>      <C>
                                                                                                       69602
</TABLE>

        References in the shaded area are for Lender's use only and do not limit
        the applicability of this document to any particular loan or item.

<TABLE>
<S>                                                           <C>
BORROWER:    CELL & MOLECULAR TECHNOLOGIES, INC.(TIN:         LENDER:    PNC BANK, NATIONAL ASSOCIATION
             223512377)                                                  201 PENN AVENUE
             580 MARSHALL STREET                                         SCRANTON, PA 18503
             PHILLIPSBURG, NJ 08865
Guarantor:   SENTIGEN HOLDING CORPORATION
             434 EAST COOPER STREET
             ASPEN, CO 81611
</TABLE>

AMOUNT OF GUARANTY. The principal amount or this Guaranty Is Seven Hundred
Twenty Thousand & 00/100 Dollars ($ 720,000.00).

CONTINUING GUARANTY. FOR GOOD AND VALUABLE CONSIDERATION, SENTIGEN HOLDING
CORPORATION ("GUARANTOR") ABSOLUTELY AND UNCONDITIONALLY GUARANTEES AND PROMISES
TO PAY TO PNC BANK, NATIONAL ASSOCIATION ("LENDER") OR ITS ORDER, IN LEGAL
TENDER OF THE UNITED STATES OF AMERICA, THE INDEBTEDNESS [AS THAT TERM IS
DEFINED BELOW) OF CELL & MOLECULAR TECHNOLOGIES, INC. ("BORROWER) TO LENDER ON
THE TERMS AND CONDITIONS SET FORTH IN THIS GUARANTY. THE OBLIGATIONS OF
GUARANTOR UNDER THIS GUARANTY ARE CONTINUING.

DEFINITIONS. The following words shall have the following meanings when used in
this Guaranty:

         BORROWER. The word "Borrower" means CELL & MOLECULAR TECHNOLOGIES,
         INC..

         GUARANTOR. The word "Guarantor" means SENTIGEN HOLDING CORPORATION.

         GUARANTY. The word "Guaranty" means this Guaranty made by Guarantor for
         the benefit of Lender dated May 23, 2001.

         INDEBTEDNESS. The word "Indebtedness" is used in its most comprehensive
         sense and means and includes any and all of Borrower's liabilities,
         obligations, debts, and indebtedness to Lender, now existing or
         hereinafter incurred or created, including, without limitation, all
         loans, advances, interest, costs, debts, overdraft indebtedness, credit
         card indebtedness, lease obligations, other obligations, and
         liabilities of Borrower, or any of them, and any present or future
         judgments against Borrower, or any of them; and whether any such
         Indebtedness is voluntarily or involuntarily incurred, due or not due,
         absolute or contingent, liquidated or unliquidated, determined or
         undetermined; whether Borrower may be liable individually or jointly
         with others, or primarily or secondarily, or as guarantor or surety;
         whether recovery on the Indebtedness may be or may become barred or
         unenforceable against Borrower for any reason whatsoever; and whether
         the Indebtedness arises from transactions which may be voidable on
         account of infancy, insanity, ultra vires, of otherwise.

         LENDER. The word "Lender" means PNC BANK, NATIONAL ASSOCIATION, its
         successors and assigns.

         RELATED DOCUMENTS. The words "Related Documents" mean and include
         without limitation all promissory notes, credit agreements, loan
         agreements, environmental agreements, guaranties, security agreements,
         mortgages, deeds of trust, and all other instruments, agreements and
         documents, whether now or hereafter existing, executed in connection
         with the Indebtedness.

MAXIMUM LIABILITY. THE MAXIMUM LIABILITY OF GUARANTOR UNDER THIS GUARANTY SHALL
NOT EXCEED AT ANY ONE TIME THE SUM OF THE PRINCIPAL AMOUNT OF $ 720,000.00, PLUS
ALL INTEREST THEREON, PLUS ALL OF LENDER'S COSTS, EXPENSES, AND ATTORNEYS' FEES
INCURRED IN CONNECTION WITH OR RELATING TO (A) THE COLLECTION OF THE
INDEBTEDNESS, (B) THE COLLECTION AND SALE OF ANY COLLATERAL FOR THE INDEBTEDNESS
OR THIS GUARANTY, OR (C) THE ENFORCEMENT OF THIS GUARANTY. ATTORNEYS' FEES
INCLUDE, WITHOUT LIMITATION, ATTORNEYS' FEES WHETHER OR NOT THERE IS A LAWSUIT,
AND IF THERE IS A LAWSUIT, ANY FEES AND COSTS FOR TRIAL AND APPEALS.

The above limitation on liability is not a restriction on the amount of the
Indebtedness of Borrower to Lender either in the aggregate or at any one time.
If Lender presently holds one or more guaranties, or hereafter receives
additional guaranties from Guarantor, the rights of Lender under all guaranties
shall be cumulative. This Guaranty shall not (unless specifically provided below
to the contrary) affect or invalidate any such other guaranties. The liability
of Guarantor will be the aggregate liability of Guarantor under the terms of
this Guaranty and any such other unterminated guaranties.

NATURE OF GUARANTY. Guarantor's liability under this Guaranty shall be open and
continuous for so long as this Guaranty remains in force. Guarantor intends to
guarantee at all times the performance and prompt payment when due, whether at
maturity or earlier by reason of acceleration or otherwise, of all lndebtedness
within the limits set forth in the preceding section of this Guaranty.
Accordingly, no payments made upon the Indebtedness will discharge or diminish
the continuing liability of Guarantor in connection with any remaining portions
of the Indebtedness or any of the Indebtedness which subsequently arises or is
thereafter incurred or contracted.

DURATION OF GUARANTY. This Guaranty will take effect when received by Lender
without the necessity of any acceptance by Lender, or any notice to Guarantor or
to Borrower, and will continue in full force until all Indebtedness incurred or
contracted before receipt by Lender of any notice of revocation shall have been
fully and finally paid and satisfied and all other obligations of Guarantor
under this Guaranty shall have been performed in full. If Guarantor elects to
revoke this Guaranty, Guarantor may only do so in writing. Guarantor's written
notice of revocation must be mailed to Lender, by certified mail, at the address
of Lender listed above or such other place as Lender may designate in writing.
Written revocation of this Guaranty will apply only to advances or new
Indebtedness created after actual receipt by Lender of Guarantor's written
revocation. For this purpose and without limitation, the term "new Indebtedness"
does not include Indebtedness which at the time of notice of revocation is
contingent, unliquidated, undetermined or not due and which later becomes
absolute, liquidated, determined or due. This Guaranty will continue to bind
Guarantor for all Indebtedness incurred by Borrower or committed by Lender prior
to receipt of Guarantor's written notice of revocation, including any
extensions, renewals, substitutions or modifications of the Indebtedness. All
renewals, extensions, substitutions, and modifications of the Indebtedness
granted after Guarantor's revocation, are contemplated under this Guaranty and,
specifically will not be considered to be new Indebtedness. This Guaranty shall
bind the estate of Guarantor as to Indebtedness created both before and after
the death or incapacity of Guarantor, regardless of Lender's actual notice of
Guarantor's death. Subject to the foregoing. Guarantor's executor or
administrator or other legal representative may terminate this Guaranty in the
same manner in which Guarantor might have terminated it and with the same
effect. Release of any other guarantor or termination of any other guaranty of
the Indebtedness shall not affect the liability of Guarantor under this
Guaranty, A revocation received by Lender from any one or more Guarantors shall
not affect the liability of any remaining Guarantors under this Guaranty. IT IS
ANTICIPATED THAT FLUCTUATIONS MAY OCCUR IN THE AGGREGATE AMOUNT OF INDEBTEDNESS
COVERED BY THIS GUARANTY, AND IT IS SPECIFICALLY ACKNOWLEDGED AND AGREED BY
GUARANTOR THAT REDUCTIONS IN THE AMOUNT OR INDEBTEDNESS, EVEN TO ZERO DOLLARS
($0.00), PRIOR TO WRITTEN REVOCATION OR THIS GUARANTY BY GUARANTOR SHALL NOT
CONSTITUTE A TERMINATION OF THIS GUARANTY. THIS GUARANTY IS BINDING UPON
GUARANTOR AND GUARANTOR'S HEIRS, SUCCESSORS AND ASSIGNS SO LONG AS ANY OF THE
GUARANTEED INDEBTEDNESS REMAINS UNPAID AND EVEN THOUGH THE INDEBTEDNESS
GUARANTEED MAY FROM TIME TO TIME BE ZERO DOLLARS ($0.00).

GUARANTOR'S AUTHORIZATION TO LENDER. Guarantor authorizes Lender, either before
or after any revocation hereof, WITHOUT NOTICE OR DEMAND AND WITHOUT LESSENING
GUARANTOR'S LIABILITY UNDER THIS GUARANTY, FROM TIME TO TIME: (A) PRIOR TO
REVOCATION AS SET FORTH ABOVE, TO MAKE ONE OR MORE ADDITIONAL SECURED OR
UNSECURED LOANS TO BORROWER, TO LEASE EQUIPMENT OR OTHER GOODS TO BORROWER, OR
OTHERWISE TO EXTEND

<PAGE>

05-23-2001                      COMMERCIAL GUARANTY                       PAGE 2
LOAN NO                             (CONTINUED)

ADDITIONAL CREDIT TO BORROWER; (b) TO ALTER, COMPROMISE, RENEW, EXTEND,
ACCELERATE, OR OTHERWISE CHANGE ONE OR MORE TIMES THE TIME TOR PAYMENT OR OTHER
TERMS OF THE INDEBTEDNESS OR ANY PART OR THE INDEBTEDNESS, INCLUDING INCREASES
AND DECREASES OF THE RATE OF INTEREST ON THE INDEBTEDNESS; EXTENSIONS MAY BE
REPEATED AND MAY BE FOR LONGER THAN THE ORIGINAL LOAN TERM; (c) TO TAKE AND HOLD
SECURITY FOR THE PAYMENT OF THIS GUARANTY OR THE INDEBTEDNESS, AND EXCHANGE,
ENFORCE, WAIVE, SUBORDINATE, FALL OR DECIDE NOT TO PERFECT, AND RELEASE ANY SUCH
SECURITIES WITH OR WITHOUT THE SUBSTITUTION OF NEW COLLATERAL; (d) TO RELEASE,
SUBSTITUTE, AGREE NOT TO SUE, OR DEAL WITH ANY ONE OR MORE OF BORROWERS
SURETIES, ENDORSERS, OR OTHER GUARANTORS ON ANY TERMS OR IN ANY MANNER LENDER
MAY CHOOSE; (e) TO DETERMINE HOW, WHEN AND WHAT APPLICATION OF PAYMENTS AND
CREDITS SHALL BE MADE ON THE INDEBTEDNESS; (f) TO APPLY SUCH SECURITY AND DIRECT
THE ORDER OR MANNER OF SALE THEREOF, INCLUDING WITHOUT LIMITATION, ANY
NONJUDICIAL SALE PERMITTED BY THE TERMS OF THE CONTROLLING SECURITY AGREEMENT OR
DEED OF TRUST, AS LENDER IN ITS DISCRETION MAY DETERMINE; (g) TO SELL, TRANSFER,
ASSIGN, OR GRANT PARTICIPATIONS IN ALL OR ANY PART OF THE INDEBTEDNESS; AND (h)
TO ASSIGN OR TRANSFER THIS GUARANTY IN WHOLE OR IN PART.

GUARANTOR'S REPRESENTATIONS AND WARRANTIES. Guarantor represents and warrants to
Lender that (a) no representations or agreements of any kind have been made to
Guarantor which would limit or qualify in any way the terms of this Guaranty;
(b) this Guaranty is executed at Borrower's request and not at the request of
Lender; (c) Guarantor has full power, right and authority to enter into this
Guaranty; (d) the provisions of this Guaranty do not conflict with or result in
a default under any agreement or other instrument binding upon Guarantor and do
not result in a violation of any law, regulation, court decree or order
applicable to Guarantor; (e) Guarantor has not and will not, without the prior
written consent of Lender, sell, lease, assign, encumber, hypothecate, transfer,
or otherwise dispose of all or substantially all of Guarantor's assets, or any
interest therein; (f) upon Lender's request, Guarantor will provide to Lender
financial and credit information in form acceptable to Lender, and all such
financial information which currently has been, and all future financial
information which will be provided to Lender is and will be true and correct in
all material respects and fairly present the financial condition of Guarantor as
of the dates the financial information is provided; (g) no material adverse
change has occurred in Guarantor's financial condition since the date of the
most recent financial statements provided to Lender and no event has occurred
which may materially adversely affect Guarantor's financial condition; (h) no
litigation, claim, investigation, administrative proceeding or similar action
(including those for unpaid taxes) against Guarantor is pending or threatened;
(i) Lender has made no representation to Guarantor as to the creditworthiness of
Borrower; and (j) Guarantor has established adequate means of obtaining from
Borrower on a continuing basis information regarding Borrower's financial
condition. Guarantor agrees to keep adequately informed from such means of any
facts, events, or circumstances which might in any way affect Guarantor's risks
under this Guaranty, and Guarantor further agrees that Lender shall have no
obligation to disclose to Guarantor any information or documents acquired by
Lender in the course of its relationship with Borrower.

GUARANTOR'S WAIVERS. Except as prohibited by applicable law, Guarantor waives
any right to require Lender (a) to continue lending money or to extend other
credit to Borrower; (b) to make any presentment, protest, demand, or notice of
any kind, including notice of any nonpayment of the Indebtedness or of any
nonpayment related to any collateral, or notice of any action or nonaction on
the part of Borrower, Lender, any surety, endorser, or other guarantor in
connection with the Indebtedness or in connection with the creation of new or
additional loans or obligations; (c) to resort for payment or to proceed
directly or at once against any person, including Borrower or any other
guarantor; (d) to proceed directly against or exhaust any collateral held by
Lender from Borrower, any other guarantor, or any other person; (e) to give
notice of the terms, time, and place of any public or private sale of personal
property security held by Lender from Borrower or to comply with any other
applicable provisions of the Uniform Commercial Code; (f) to pursue any other
remedy within Lender's power; or (g) to commit any act or omission of any kind,
or at any time, with respect to any matter whatsoever.

Guarantor also waives any and all rights or defenses arising by reason of (a)
any "one action" or "anti-deficiency" law or any other law which may prevent
Lender from bringing any action, including a claim for deficiency, against
Guarantor, before or after Lender's commencement or completion [ILLEGIBLE] any
foreclosure action, either judicially or by exercise of a power of sale; (b) any
election of remedies by Lender which destroys or otherwise advers[ILLEGIBLE]
affects Guarantor's subrogation rights or Guarantor's rights to proceed against
Borrower for reimbursement, including without limitation, any loss of rights
Guarantor may suffer by reason of any law limiting, qualifying, or discharging
the Indebtedness; (c) any disability or other defense of Borrower, of any other
guarantor, or of any other person, or by reason of the cessation of Borrower's
liability from any cause whatsoever, other than payment in full in legal tender,
of the Indebtedness; (d) any right to claim discharge of the Indebtedness on the
basis of unjustified impairment of any collateral for the Indebtedness; (e) any
statute of limitations, if at any time any action or suit brought by Lender
against Guarantor is commenced there is outstanding Indebtedness of Borrower to
Lender which is not barred by any applicable statute of limitations; or (f) any
defenses given to guarantors at law or in equity other than actual payment and
performance of the Indebtedness. If payment is made by Borrower, whether
voluntarily or otherwise, or by any third party, on the Indebtedness and
thereafter Lender is forced to remit the amount of that payment to Borrower's
trustee in bankruptcy or to any similar person under any federal or state
bankruptcy law or law for the relief of debtors, the Indebtedness shall be
considered unpaid for the purpose of enforcement of this Guaranty.

Guarantor further waives and agrees not to assert or claim at any time any
deductions to the amount guaranteed under this Guaranty for any claim of setoff,
counterclaim, counter demand, recoupment or similar right, whether such claim,
demand or right may be asserted by the Borrower, the Guarantor, or both.

GUARANTOR'S UNDERSTANDING WITH RESPECT TO WAIVERS. Guarantor warrants and agrees
that each of the waivers set forth above is made with Guarantor's full knowledge
of its significance and consequences and that, under the circumstances, the
waivers are reasonable and not contrary to public policy or law. If any such
waiver is determined to be contrary to any applicable law or public policy, such
waiver shall be effective only to the extent permitted by law or public policy.

LENDER'S RIGHT OF SETOFF. In addition to all liens upon and rights of setoff
against the moneys, securities or other property of Guarantor given to Lender by
law, Lender shall have, with respect to Guarantor's obligations to Lender under
this Guaranty and to the extent permitted by law, a contractual security
interest in and a right of setoff against, and Guarantor hereby assigns,
conveys, delivers, pledges, and transfers to Lender all of Guarantor's right,
title and interest in and to, all deposits, moneys, securities and other
property of Guarantor now or hereafter in the possession of or on deposit with
Lender, whether held in a general or special account or deposit, whether held
jointly with someone else, or whether held for safekeeping or otherwise,
excluding however all IRA, Keogh, and trust accounts. Every such security
interest and right of setoff may be exercised without demand upon or notice to
Guarantor. No security interest or right of setoff shall be deemed to have been
waived by any act or conduct on the part of Lender or by any neglect to exercise
such right of setoff or to enforce such security interest or by any delay in so
doing. Every right of setoff and security interest shall continue in full force
and effect until such right of setoff or security interest is specifically
waived or released by an instrument in writing executed by Lender.

SUBORDINATION OF BORROWER'S DEBTS TO GUARANTOR. Guarantor agrees that the
Indebtedness of Borrower to Lender, whether now existing or hereafter created,
shall be prior to any claim that Guarantor may now have or hereafter acquire
against Borrower, whether or not Borrower becomes insolvent. Guarantor hereby
expressly subordinates any claim Guarantor may have against Borrower, upon any
account whatsoever, to any claim that Lender may now or hereafter have against
Borrower. In the event of insolvency and consequent liquidation of the assets of
Borrower through bankruptcy, by an assignment for the benefit of creditors, by
voluntary liquidation, or otherwise, the assets of Borrower applicable to the
payment of the claims of both Lender and Guarantor shall be paid to Lender and
shall be first applied by Lender to the Indebtedness of Borrower to Lender.
Guarantor does hereby assign to Lender all claims which it may have or acquire
against Borrower or against any assignee or trustee in bankruptcy of Borrower;
provided however, that such assignment shall be effective only for the purpose
of assuring to Lender full payment in legal tender of the Indebtedness, If
Lender so requests, any notes or credit agreements now or hereafter evidencing
any debts or obligations of Borrower to Guarantor shall be marked with a legend
that the same are subject to this Guaranty and shall be delivered to Lender.
Guarantor agrees, and Lender

<PAGE>

05-23-2001                        COMMERCIAL GUARANTY                     PAGE 3
LOAN NO                               (CONTINUED)

hereby is authorized, in the name of Guarantor, from time to time to execute and
file financing statements and continuation statements and to execute such other
documents and to take such other actions as Lender deems necessary or
appropriate to perfect, preserve and enforce its rights under this Guaranty.

MISCELLANEOUS PROVISIONS. The following miscellaneous provisions are a part of
this Guaranty:

         AMENDMENTS. This Guaranty, together with any Related Documents,
         constitutes the entire understanding and agreement of the parties as to
         the matters set forth in this Guaranty. No alteration of or amendment
         to this Guaranty shall be effective unless given in writing and signed
         by the party or parties sought to be charged or bound by the alteration
         or amendment.

         APPLICABLE LAW. This Guaranty has been delivered to Lender and accepted
         by Lender in the Commonwealth of Pennsylvania. If there is a lawsuit,
         Guarantor agrees upon Lender's request to submit to the jurisdiction of
         the courts of LACKAWANNA County, Commonwealth of Pennsylvania. Lender
         and Guarantor hereby waive the right to any jury trial in any action,
         proceeding, or counterclaim brought by either Lender or Guarantor
         against the other. This Guaranty shall be governed by and construed in
         accordance with the laws of the Commonwealth of Pennsylvania.

         ATTORNEYS' FEES; EXPENSES. Guarantor agrees to pay upon demand all of
         Lender's costs and expenses, including attorneys' fees and Lender's
         legal expenses, incurred in connection with the enforcement of this
         Guaranty. Lender may pay someone else to help enforce this Guaranty,
         and Guarantor shall pay the costs and expenses of such enforcement.
         Costs and expenses include Lender's attorneys' fees and legal expenses
         whether or not there is a lawsuit, including attorneys' fees and legal
         expenses for bankruptcy proceedings (and including efforts to modify
         or vacate any automatic stay or injunction), appeals, and any
         anticipated post-judgment collection services. Guarantor also shall pay
         all court costs and such additional fees as may be directed by the
         court.

         NOTICES. All notices required to be given by either party to the other
         under this Guaranty shall be in writing, may be sent by telefacsimile
         (unless otherwise required by law), and, except for revocation notices
         by Guarantor, shall be effective when actually delivered or when
         deposited with a nationally recognized overnight courier, or when
         deposited in the United States mail, first class postage prepaid,
         addressed to the party to whom the notice is to be given at the address
         shown above or to such other addresses as either party may designate to
         the other in writing. All revocation notices by Guarantor shall be in
         writing and shall be effective only upon delivery to Lender as provided
         above in the section titled "DURATION OF GUARANTY." If there is more
         than one Guarantor, notice to any Guarantor will constitute notice to
         all Guarantors. For notice purposes, Guarantor agrees to keep Lender
         informed at all times of Guarantor's current address.

         INTERPRETATION. In all cases where there is more than one Borrower or
         Guarantor, then all words used in this Guaranty in the singular shall
         be deemed to have been used in the plural where the context and
         construction so require; and where there is more than one Borrower
         named in this Guaranty or when this Guaranty is executed by more than
         one Guarantor, the words "Borrower" and,"Guarantor" respectively shall
         mean all and any one or more of them. The words "Guarantor,"
         "Borrower," and "Lender" include the heirs, successors, assigns, and
         transferees of each of them. Caption headings in this Guaranty are for
         convenience purposes only and are not to be used to interpret or define
         the provisions of this Guaranty. If a court of competent jurisdiction
         finds any provision of this Guaranty to be invalid or unenforceable as
         to any person or circumstance, such finding shall not render that
         provision invalid or unenforceable as to any other persons or
         circumstances, and all provisions of this Guaranty in all other
         respects shall remain valid and enforceable. If any one or more of
         Borrower or Guarantor are corporations or partnerships, it is not
         necessary for Lender to inquire into the powers of Borrower or
         Guarantor or of the officers, directors, partners, or agents acting or
         purporting to act on their behalf, and any Indebtedness made or created
         in reliance upon the professed exercise of such powers shall be
         guaranteed under this Guaranty.

         WAIVER. Lender shall not be deemed to have waived any rights under this
         Guaranty unless such waiver is given in writing and signed by Lender.
         No delay or omission on the part of Lender in exercising any right
         shall operate as a waiver of such right or any other right. A waiver by
         Lender of a provision of this Guaranty shall not prejudice or
         constitute a waiver of Lender's right otherwise to demand strict
         compliance with that provision or any other provision of this Guaranty.
         No prior waiver by Lender, nor any course of dealing between Lender and
         Guarantor, shall constitute a waiver of any of Lender's rights or of
         any of Guarantor's obligations as to any future transactions. Whenever
         the consent of Lender is required under this Guaranty, the granting of
         such consent by Lender in any instance shall not constitute continuing
         consent to subsequent instances where such consent is required and in
         all cases such consent may be granted or withheld in the sole
         discretion of Lender.

MODIFICATION OF CONFESSION OF JUDGMENT. Notwithstanding the attorney's
commission provided for in the paragraph of this Note entitled "Confession of
Judgment" (which is included in the warrant lor purposes of establishing a sum
certain), the amount of attorneys' fees that Lender may recover from Borrower
shall not exceed the actual attorneys' fees incurred by Lender.

CONFESSION OF JUDGMENT. GUARANTOR HEREBY IRREVOCABLY AUTHORIZES AND EMPOWERS ANY
ATTORNEY OR THE PROTHONOTARY OR CLERK OF ANY COURT IN THE COMMONWEALTH OF
PENNSYLVANIA, OR ELSEWHERE, TO APPEAR AT ANY TIME FOR GUARANTOR AFTER A DEFAULT
UNDER THIS GUARANTY, AND WITH OR WITHOUT COMPLAINT FILED, AS OF ANY TERM,
CONFESS OR ENTER JUDGMENT AGAINST GUARANTOR FOR THE ENTIRE PRINCIPAL BALANCE OF
THIS GUARANTY, ALL ACCRUED INTEREST, LATE CHARGES, AND ANY AND ALL AMOUNTS
EXPENDED OR ADVANCED BY LENDER RELATING TO ANY COLLATERAL SECURING THE
INDEBTEDNESS TOGETHER WITH INTEREST ON SUCH AMOUNTS, TOGETHER WITH COSTS OF
SUIT, AND AN ATTORNEY'S COMMISSION OF TEN PERCENT (10%) OF THE UNPAID PRINCIPAL
BALANCE AND ACCRUED INTEREST FOR COLLECTION, BUT IN ANY EVENT NOT LESS THAN FIVE
HUNDRED DOLLARS ($500) ON WHICH JUDGMENT OR JUDGMENTS ONE OR MORE EXECUTIONS MAY
ISSUE IMMEDIATELY; AND FOR SO DOING, THIS GUARANTY OR A COPY OF THIS GUARANTY
VERIFIED BY AFFIDAVIT SHALL BE SUFFICIENT WARRANT. THE AUTHORITY GRANTED IN THIS
GUARANTY TO CONFESS JUDGMENT AGAINST GUARANTOR SHALL NOT BE EXHAUSTED BY ANY
EXERCISE OF THAT AUTHORITY, BUT SHALL CONTINUE FROM TIME TO TIME AND AT ALL
TIMES UNTIL PAYMENT IN FULL OF ALL AMOUNTS DUE UNDER THIS GUARANTY. GUARANTOR
HEREBY WAIVES ANY RIGHT GUARANTOR MAY HAVE TO NOTICE OR TO A HEARING IN
CONNECTION WITH ANY SUCH CONFESSION OF JUDGMENT, EXCEPT ANY NOTICE AND/OR
HEARING REQUIRED UNDER APPLICABLE LAW WITH RESPECT TO EXECUTION OF THE
JUDGMENT, AND STATES THAT EITHER A REPRESENTATIVE OF LENDER SPECIFICALLY CALLED
THIS CONFESSION OF JUDGMENT PROVISION TO GUARANTOR'S ATTENTION OR GUARANTOR HAS
BEEN REPRESENTED BY INDEPENDENT LEGAL COUNSEL.

EACH UNDERSIGNED GUARANTOR ACKNOWLEDGES HAVING READ ALL THE PROVISIONS OF THIS
GUARANTY AND AGREES TO ITS TERMS. IN ADDITION, EACH GUARANTOR UNDERSTANDS THAT
THIS GUARANTY IS EFFECTIVE UPON GUARANTOR'S EXECUTION AND DELIVERY OF THIS
GUARANTY TO LENDER AND THAT THE GUARANTY WILL CONTINUE UNTIL TERMINATED IN THE
MANNER SET FORTH IN THE SECTION TITLED "DURATION OF GUARANTY." NO FORMAL
ACCEPTANCE BY LENDER IS NECESSARY TO MAKE THIS GUARANTY EFFECTIVE. THIS GUARANTY
IS DATED MAY 23, 2001.

<PAGE>

05-23-2001                      COMMERCIAL GUARANTY                       PAGE 4
LOAN NO                             (CONTINUED)

THIS GUARANTY HAS BEEN SIGNED AND SEALED BY THE UNDERSIGNED.

GUARANTOR:

SENTIGEN HOLDING CORPORATION

By:/s/Joseph K. Pagano     (SEAL)
   ------------------------------
   JOSEPH K. PAGANO, CHAIRMAN OF BOARD

                            CORPORATE ACKNOWLEDGMENT

                                            JOHN MARK HOPKINS
STATE OF NEW YORK        )          Notary Public, State of New York
                         )SS                 No. 01HO5025754
                                      Qualified in New York County
COUNTY OF NEW YORK       )          Commission Expires April 4, 2002.

On this 29th day of May, 2001, before me, the undersigned Notary Public,
personally appeared JOSEPH A. PAGANO, CHAIRMAN OF BOARD of SENTIGEN HOLDING
CORPORATION, and known to me to be an authorized agent of the corporation that
executed the Commercial Guaranty and acknowledged the Guaranty to be the free
and voluntary act and deed of the corporation, by authority of its Bylaws or by
resolution of its board of directors, for the uses and purposes therein
mentioned, and on oath slated that he or she is authorized to execute this
Guaranty and in fact executed the Guaranty on behalf of the corporation.
<TABLE>
<S>                                                    <C>
By   John Mark Hopkins                                 RESIDING AT 37 EAST 64 ST, NYC 10021
    -------------------
NOTARY PUBLIC IN AND FOR THE STATE OF NEW YORK         MY COMMISSION EXPIRES     4/4/2002
</TABLE>

LASER PRO, Reg. U.S. Pat & T.M. Off., Ver. 3.29a (C) Concentrex 2001 All rights
Reserved. [PA-E20A E3. 29 F3.29 CELL MOLE. LN C68.ovl]

<PAGE>

                        CORPORATE RESOLUTION TO GUARANTEE
<TABLE>
<CAPTION>
PRINCIPAL        LOAN DATE  MATURITY    LOAN NO   CALL   COLLATERAL     ACCOUNT    OFFICER   INITIALS
<C>             <C>         <C>         <C>       <C>    <C>            <C>        <C>       <C>
$720,000.00     05-23-2001                                                          69602   [ILLEGIBLE]
</TABLE>

  References in the shaded area are for Lender's use only and do not limit the
         applicability of this document to any particular loan or item.

<TABLE>
<S>                                                        <C>
BORROWER:   CELL & MOLECULAR TECHNOLOGIES, INC. (TIN:      LENDER:   PNC BANK, NATIONAL ASSOCIATION
            223512377)                                               201 PENN AVENUE
            580 MARSHALL STREET                                      SCRANTON, PA 18503
            PHILLIPSBURG,NJ 08865

GUARANTOR:  SENTIGEN HOLDING CORPORATION
            434 EAST COOPER STREET
            ASPEN, CO 81611
</TABLE>

I, THE UNDERSIGNED SECRETARY OR ASSISTANT SECRETARY OF SENTIGEN HOLDING
CORPORATION (THE "CORPORATION"), HEREBY CERTIFY THAT the Corporation is
organized and existing under and by virtue of the laws of the State of Colorado
with its principal office at 434 EAST COOPER STREET, ASPEN, CO 81611.

I FURTHER CERTIFY that at a meeting of the Directors of the Corporation, duly
called and held on 5/29/01, at which a quorum was present and voting, or by
other duly authorized corporate action in lieu of a meeting, the following
resolutions were adopted:

BE IT RESOLVED, that ANY ONE (1) of the following named officers, employees, or
agents of this Corporation, whose actual signatures are shown below:

<TABLE>
<CAPTION>
     NAME                       POSITION                     ACTUAL SIGNATURE
    -----                       --------                     ----------------
<S>                        <C>                             <C>
JOSEPH K. PAGANO           CHAIRMAN OF BOARD               /s/ Joseph K. Pagano
</TABLE>

acting for and on behalf of the Corporation and as its act and deed be, and he
or she hereby is, authorized and empowered:

         GUARANTY. To guarantee or act as surety for loans or other financial
         accommodations to CELL & MOLECULAR TECHNOLOGIES, INC. from PNC BANK,
         NATIONAL ASSOCIATION ("Lender") on such guarantee or surety terms as
         may be agreed upon between the officers or employees of this
         Corporation and Lender and in such sum or sums of money as in his or
         her judgment should be guaranteed or assured, not exceeding, however,
         at any one time the amount of SEVEN HUNDRED TWENTY THOUSAND & 00/100
         DOLLARS ($ 720,000.00), in addition to such sum or sums of money as may
         be currently guaranteed by the Corporation to Lender (the "Guaranty").

         GRANT SECURITY. To mortgage, pledge, transfer, endorse, hypothecate, or
         otherwise encumber and deliver to Lender, as security for the Guaranty,
         any property now or hereafter belonging to the Corporation or in which
         the Corporation now or hereafter may have an interest, including
         without limitation all real property and all personal property
         (tangible or intangible) of the Corporation. Such property may be
         mortgaged, pledged, transferred, endorsed, hypothecated, or encumbered
         at the time such loans are obtained or such indebtedness is incurred,
         or at any other time or times, and may be either in addition to or in
         lieu of any property theretofore mortgaged, pledged, transferred,
         endorsed, hypothecated, or encumbered. The provisions of these
         Resolutions authorizing or relating to the pledge, mortgage, transfer,
         endorsement, hypothecation, granting of a security interest in, or in
         any way encumbering, the assets of the Corporation shall include,
         without limitation, doing so in order to lend collateral security for
         the indebtedness, now or hereafter existing, and of any nature
         whatsoever, of CELL & MOLECULAR TECHNOLOGIES, INC. to Lender. The
         Corporation has considered the value to itself of lending collateral in
         support of such indebtedness, and the Corporation represents to Lender
         that the Corporation is benefited by doing so.

         EXECUTE SECURITY DOCUMENTS. To execute and deliver to Lender the forms
         of mortgage, deed of trust, pledge agreement, hypothecation agreement,
         and other security agreements and financing statements which may be
         submitted by Lender, and which shall evidence the terms and conditions
         under and pursuant to which such liens and encumbrances, or any of
         them, are given; and also to execute and deliver to Lender any other
         written instruments, any chattel paper, or any other collateral, of any
         kind or nature, which he or she may in his or her discretion deem
         reasonably necessary or proper in connection with or pertaining to the
         giving of the liens and encumbrances.

         FURTHER ACTS. To do and perform such other acts and things and to
         execute and deliver such other documents and agreements, INCLUDING
         AGREEMENTS WAIVING THE RIGHT TO A TRIAL BY JURY AND CONFESSING JUDGMENT
         AGAINST THE CORPORATION, as he or she may in his or her discretion deem
         reasonably necessary or proper in order to carry into effect the
         provisions of these Resolutions.

BE IT FURTHER RESOLVED, that the Corporation will notify Lender in writing at
Lender's address shown above (or such other addresses as Lender may designate
from time to time) prior to any (a) change in the name of the Corporation, (b)
change in the assumed business name(s) of the Corporation, (c) change in the
management of the Corporation,, (d) change in the authorized signer(s), (e)
conversion of the Corporation to a new or different type of business entity, or
(f) change in any other aspect of the Corporation that directly or indirectly
relates to any agreements between the Corporation and Lender. No change in the
name of the Corporation will take effect until after Lender has been notified.

BE IT FURTHER RESOLVED, that any and all acts authorized pursuant to these
Resolutions and performed prior to the passage of these Resolutions are hereby
ratified and approved, that these Resolutions shall remain in full force and
effect and Lender may rely on these Resolutions until written notice of his or
her revocation shall have been delivered to and received by Lender. Any such
notice shall not affect any of the Corporation's agreements or commitments in
effect at the time notice is given.

I FURTHER CERTIFY that the officer, employee, or agent named above is duly
elected, appointed, or employed by or for the Corporation, as the case may be,
and occupies the position set opposite the name; that the foregoing Resolutions
now stand of record on the books of the Corporation; and that the Resolutions
are in full force and effect and have not been modified or revoked in any manner
whatsoever.

<PAGE>

                        CORPORATE RESOLUTION TO GUARANTEE
<TABLE>
<CAPTION>

PRINCIPAL      LOAN DATE      MATURITY    LOAN NO   CALL    COLLATERAL    ACCOUNT    OFFICER   INITIALS
<S>          <C>              <C>         <C>       <C>     <C>           <C>        <C>        <C>
$720,000.00     05-23-2001                                                            69602      JKP
</TABLE>

  References in the shaded area are for Lander's use only and do not limit the
         applicability of this document to any particular loan or item.

<TABLE>
<S>                                                        <C>
BORROWER:   CELL & MOLECULAR TECHNOLOGIES, INC. (TIN:      LENDER:   PNC BANK, NATIONAL ASSOCIATION
            223512377)                                               201 PENN AVENUE
            580 MARSHALL STREET                                      SCRANTON, PA 18503
            PHILLIPSBURG, NJ 08865

GUARANTOR:  SENTIGEN HOLDING CORPORATION
            434 EAST COOPER STREET
            ASPEN, CO 81611
</TABLE>

I, THE UNDERSIGNED SECRETARY OR ASSISTANT SECRETARY OF SENTIGEN HOLDING
CORPORATION (THE "CORPORATION"), HEREBY CERTIFY THAT the Corporation is
organized and existing under and by virtue of the laws of the State of Colorado
with its principal office at 434 EAST COOPER STREET, ASPEN, CO 81611.

I FURTHER CERTIFY that at a meeting of the Directors of the Corporation, duly
called and held on 5/29/01, at which a quorum was present and voting, or by
other duly authorized corporate action in lieu of a meeting, the following
resolutions were adopted:

BE IT RESOLVED, that ANY ONE (1) of the following named officers, employees, or
agents of this Corporation, whose actual signatures are shown below:

<TABLE>
<CAPTION>
      NAME                                    POSITION                       ACTUAL SIGNATURE
---------------                           ----------------                   ----------------
<S>                                       <C>                              <C>
JOSEPH K. PAGANO                          CHAIRMAN OF BOARD                /s/ Joseph K. Pagano
</TABLE>

acting for and on behalf of the Corporation and as its act and deed be, and he
or she hereby is, authorized and empowered:

         GUARANTY. To guarantee or act as surety for loans or other financial
         accommodations to CELL & MOLECULAR TECHNOLOGIES, INC. from PNC BANK,
         NATIONAL ASSOCIATION ("Lender") on such guarantee or surety terms as
         may be agreed upon between the officers or employees of this
         Corporation and Lender and in such sum or sums of money as in his or
         her judgment should be guaranteed or assured, not exceeding, however,
         at any one time the amount of SEVEN HUNDRED TWENTY THOUSAND & 00/100
         DOLLARS ($ 720,000.00), in addition to such sum or sums of money as may
         be currently guaranteed by the Corporation to Lender (the "Guaranty").

         GRANT SECURITY. To mortgage, pledge, transfer, endorse, hypothecate, or
         otherwise encumber and deliver to Lender, as security for the Guaranty,
         any property now or hereafter belonging to the Corporation or in which
         the Corporation now or hereafter may have an interest, including
         without limitation all real property and all personal property
         (tangible or intangible) of the Corporation. Such property may be
         mortgaged, pledged, transferred, endorsed, hypothecated, or encumbered
         at the time such loans are obtained or such indebtedness is incurred,
         or at any other time or times, and may be either in addition to or in
         lieu of any property theretofore mortgaged, pledged, transferred,
         endorsed, hypothecated, or encumbered. The provisions of these
         Resolutions authorizing or relating to the pledge, mortgage, transfer,
         endorsement, hypothecation, granting of a security interest in, or in
         any way encumbering, the assets of the Corporation shall include,
         without limitation, doing so in order to lend collateral security for
         the indebtedness, now or hereafter existing, and of any nature
         whatsoever, of CELL & MOLECULAR TECHNOLOGIES, INC. to Lender. The
         Corporation has considered the value to itself of lending collateral in
         support of such indebtedness, and the Corporation represents to Lender
         that the Corporation is benefited by doing so.

         EXECUTE SECURITY DOCUMENTS. To execute and deliver to Lender the forms
         of mortgage, deed of trust, pledge agreement, hypothecation agreement,
         and other security agreements and financing statements which may be
         submitted by Lender, and which shall evidence the terms and conditions
         under and pursuant to which such liens and encumbrances, or any of
         them, are given; and also to execute and deliver to Lender any other
         written instruments, any chattel paper, or any other collateral, of any
         kind or nature, which he or she may in his or her discretion deem
         reasonably necessary or proper in connection with or pertaining to the
         giving of the liens and encumbrances.

         FURTHER ACTS. To do and perform such other acts and things and to
         execute and deliver such other documents and agreements, INCLUDING
         AGREEMENTS WAIVING THE RIGHT TO A TRIAL BY JURY AND CONFESSING JUDGMENT
         AGAINST THE CORPORATION, as he or she may in his or her discretion deem
         reasonably necessary or proper in order to carry into effect the
         provisions of these Resolutions.

BE IT FURTHER RESOLVED, that the Corporation will notify Lender in writing at
Lender's address shown above (or such other addresses as Lender may designate
from time to time) prior to any (a) change in the name of the Corporation, (b)
change in the assumed business name(s) of the Corporation, (c) change in the
management of the Corporation,, (d) change in the authorized signer(s), (e)
conversion of the Corporation to a new or different type of business entity, or
(f) change in any other aspect of the Corporation that directly or indirectly
relates to any agreements between the Corporation and Lender. No change in the
name of the Corporation will take effect until after Lender has been notified.

BE IT FURTHER RESOLVED, that any and all acts authorized pursuant to these
Resolutions and performed prior to the passage of these Resolutions are hereby
ratified and approved, that these Resolutions shall remain in full force and
effect and Lender may rely on these Resolutions until written notice of his or
her revocation shall have been delivered to and received by Lender. Any such
notice shall not affect any of the Corporation's agreements or commitments in
effect at the time notice is given.

I FURTHER CERTIFY that the officer, employee, or agent named above is duly
elected, appointed, or employed by or for the Corporation, as the case may be,
and occupies the position set opposite the name; that the foregoing Resolutions
now stand of record on the books of the Corporation; and that the Resolutions
are in full force and effect and have not been modified or revoked in any manner
whatsoever.

<PAGE>

IN TESTIMONY WHEREOF, I HAVE HEREUNTO SET MY HAND AND SEAL ON MAY 23, 2001 AND
ATTEST THAT THE SIGNATURES SET OPPOSITE THE NAMES LISTED ABOVE ARE THEIR GENUINE
SIGNATURES.

                                    CERTIFIED TO AND ATTESTED BY:
                                    /s/ Frederick B. Rolff   (SEAL)
                                    /s/ Thomas J. Livelli    (SEAL)
NOTE: In case the Secretary or other certifying officer is designated by the
foregoing resolutions is one of the signing officers, it is advisable to have
this certificate signed by a second Officer or Director of the Corporation.

LASER PRO,Reg. U.S. Pat. & T.M. Off., Ver. 3.29a (C) Concentrex 2001 All rights
reserved. [PA-C1OB E3.29F3.29 CELL MOLE.LN C68.OVL]