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                                                                     Exhibit 2.5


                              AMENDED AND RESTATED
                             INDEMNITY DEED OF TRUST

     This Amended and Restated Indemnity Deed of Trust (this "Deed of Trust"),
effective this 28th day of February, 2002, by and between QIAGEN Sciences, Inc.,
a corporation organized under the laws of the State of Maryland, with a mailing
address at 19825 Executive Park Circle, Germantown, Maryland 20874 (hereinafter
referred to as "Grantor") and Richard Sugarman, Esq. having a mailing address at
5801 Nicholson Lane, Suite 234, Rockville, Maryland 20825 (hereinafter referred
to as the "Trustee");

     Whereas, QIAGEN GmbH ("Lender") has made a loan in the principal amount of
Fifty Million Euros (EUR 50.000.000), and Borrower has executed a Promissory
Note dated November 5, 2001 (the "Original Note"), which principal amount was
stated in the Original Note to have an equivalent value of Forty Four Million
Five Hundred Ninety Thousand and No/00 United States Dollars ($44,590,000.00) as
of the date of the Original Note; and

     Whereas, Borrower and Lender desire to modify the amount and currency of
the existing indebtedness, and for said purpose Borrower has delivered an
Amended and Restated Promissory Note to Lender, dated February 28, 2002, in the
original principal amount of Forty Three Million Four Hundred Seventy Five
Thousand and No/100 Dollars ($43,475,000.00), in full substitution of the
Original Note;

     Whereas, Grantor has signed and delivered to Lender an Amended and Restated
Guaranty Agreement of even date herewith (the "Amended and Restated Guaranty")
guaranteeing the obligations of Borrower under the Amended and Restated Note,
said Amended and Restated Guaranty to be in full substitution of a Guaranty
Agreement dated November 5, 2001 (the "Original Guaranty"); and

     Whereas, the purpose of this Amended and Restated Indemnity Deed of Trust
is to secure the Grantor's obligations under the Amended and Restated Guaranty
Agreement, in full substitution of the Indemnity Deed of Trust dated November 5,
2001 and recorded among the Land Records of Montgomery County on December 13,
2001 in Liber 20155, folio 346.

     Whereas, Grantor is not the Borrower and is not primarily responsible for
payment of the obligations set forth in the Note, but has guaranteed those
obligations pursuant to the Amended and Restated Guaranty.

     Now, Therefore, This Deed of Trust Witnesseth: That to secure the prompt
performance of its obligations under said Amended and Restated Guaranty and as
herein provided, the Grantor, in consideration of the sum of One Dollar in hand
paid by said Trustee at and before the sealing and delivering of these presents,
the receipt of which is hereby acknowledged, does hereby irrevocably grant and
convey unto the Trustee, in trust, with the power of sale, the following land
and premises lying and being in Montgomery County, State of Maryland:

     Lot 6 in a subdivision entitled "GERMANTOWN BUSINESS PARK SUBDIVISION" as
     per plat thereof duly recorded among the Land Records of Montgomery County,
     Maryland in Plat Book 196, Plat No. 21326 and having the Parcel Tax
     Identification Number 03282822;

     together with all of Grantor's right, title and interest in and to the
     adjoining streets, right of way and strips and gores, water and riparian
     rights, mineral rights, rights to light and air easements which benefit the
     above described property and particularly, all of Grantor's interest in and
     to that certain Easement and Agreement between Montgomery County, Maryland
     and Grantor dated May 22, 1997 and recorded among the Land Records of
     Montgomery County in Liber 15299, Folio 113, as said easement pertains to
     the property; and

     together with all the improvements in anywise appertaining, and all the
     estate, right, title, interest, and claim, either at law or in equity or
     otherwise however, of the Grantor, of, in, to, or out of the said land and
     premises;

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     In Trust to permit said Grantor to use and occupy the said described land
and premises and to receive the rents, issues, and profits thereof, until
default be made in the payment of any indebtedness hereby secured and in the
performance of the conditions and obligations made and stipulated in the said
promissory note or in the performance of any covenant or agreement contained in
this trust; and upon the full performance of all obligations of said Amended and
Restated Guaranty and any extensions or renewals thereof, and all other costs,
attorney's fees, charges, commissions, and expenses, at any time before the sale
herein provided for to release and re-convey the said land and premises unto and
at the cost of the Grantor or the party or parties then claiming under said
Grantor.

     The Grantor, for itself and its successors and assigns, covenants and
agrees as a part of this trust, as follows:

     1. That Grantor will perform the obligations evidenced by the Amended and
Restated Guaranty secured hereby and pay, all taxes and assessments relating to
the land and premises herein described, ground rents, all charges against the
property, and all other sums which are required to be paid by Grantor under the
terms of said Amended and Restated Guaranty or this Amended and Restated Deed of
Trust, including costs, expenses and attorney's fees incurred by the Trustee or
the holder of said Amended and Restated Guaranty with respect to this trust, the
said Amended and Restated Guaranty or the land and premises herein described,
and in default of any such payment the holder of said Amended and Restated
Guaranty may pay the same, and any sum or sums so paid shall be added to the
obligations hereby secured, shall be payable on demand, shall bear full legal
interest, and shall be secured by this Amended and Restated Deed of Trust.

     2. That Grantor will keep the said premises in as good order and condition
as they are now and will not commit or permit any waste thereof, reasonable wear
and tear accepted; and that Grantor will not act or fail to act in any manner
which will jeopardize the lien of this Amended and Restated Deed of Trust.

     3. That Grantor will keep the improvements now existing, or hereafter
erected on said land, insured against loss by fire and other hazards, casualties
and contingencies in such amounts and for such periods as may be required by the
holder of said guaranty agreement, and will pay promptly, when due, any premiums
on such insurance. All insurance shall be carried in companies approved by the
holder of said Amended and Restated Guaranty and the policies and renewals
thereof shall be held by said holder and have attached thereto loss payable
clauses in favor of and in form acceptable to the holder of said Amended and
Restated Guaranty. In event of loss, Grantor will give immediate notice by mail
to the holder of said Amended and Restated Note, who may make proof of loss if
not made promptly by Grantor, and each insurance company concerned is hereby
authorized and directed to make payment for such loss directly to and to the
order of the holder of said Amended and Restated Guaranty, and the insurance
proceeds or any part thereof may be applied by such holder at such holders
option either to the reduction of the obligations hereby secured or to the
restoration or repair of the security property. In the event of sale under the
terms of this Amended and Restated Deed of Trust or other transfer of title to
said security property in extinguishment of the obligations secured hereby, all
right, title and interest of Grantor in and to any insurance policies then in
force shall pass to the purchaser or grantee.

     4. That in the event the ownership of the security property becomes vested
in a person other than Grantor, the holder of said Amended and Restated Guaranty
may, without notice to Grantor, deal with such successor(s) in interest with
reference to this instrument and the obligations secured hereby in the same
manner as with Grantor, and any extension of the time of the performance of the
obligations or any other modification of the terms of the obligations at the
instance of the then owner shall not relieve Grantor of its liability on the
Amended and Restated Guaranty hereby secured or from the performance of any of
the covenants and agreements contained herein whether said extension or
modification be made with or without the consent of Grantor.

     5. That the irrevocable power to substitute one or more of the trustees
named herein or substituted therefore is expressly reserved to the holder of the
Amended and Restated Guaranty secured by this Amended and Restated Deed of Trust
to be exercised any time hereafter no matter how often without notice and
without specifying any reason therefore by filing for record among the land
records where this instrument is recorded a Deed of Appointment, and thereupon
all of the title and estate, powers, rights and duties of the trustee thus
superseded shall terminate and shall be vested in the successor trustee or
trustees. Grantor and the Trustee herein named or that hereafter may be
substituted hereunder expressly waive notice of the exercise of this power, the
giving of bond by any trustee, and any requirement for application to any Court
for the removal, substitution or appointment of a trustee hereunder.

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     6. That Grantor's failure to perform any of its obligations under this
Amended and Restated Deed of Trust or under said Amended and Restated Guaranty
shall constitute a default and all obligations secured hereby shall immediately
become due and payable at the option of the holder of said Amended and Restated
Guaranty. Any time thereafter, at the request of the holder of said Amended and
Restated Guaranty, the Trustee shall have the power and it shall be their duty
to sell said land and premises or any part thereof at public auction, in such
manner, at such time and place, upon such terms and conditions, and upon such
public notice as the Trustee may deem best for the interest of all concerned,
consisting of advertisement in a newspaper of general circulation in the county
or city in which the security property is located for at least once a week for
three successive weeks or for such period as applicable law may require and, in
case of default of any purchaser, to re-sell with such postponement of sale or
re-sale and upon such public notice thereof as the Trustee may determine, and
upon compliance by the purchaser with the terms of sale, and upon judicial
approval as may be required by law, convey said land and premises in fee simple
to and at the cost of the purchaser, who shall not be liable to see to the
application of the purchase money; and from the proceeds of sale: FIRST, to pay
all proper costs and charges, including but not limited to court costs,
advertising expenses, auctioneer's allowance, the expenses, if any, required to
correct any irregularity in the title, premium for Trustee's bond, auditor's
fee, attorney's fee, and all other expenses of sale incurred in and about the
protection and execution of this trust, and all moneys advanced for taxes,
assessments, insurance, and with interest thereon as provided herein, and all
taxes due upon said land and premises at time of sale; SECOND, to pay the
reasonable fee of the Trustee, which fee shall be charged by the Trustee based
on his usual and customary billing rates, and shall not exceed five percent of
the sale proceeds; THIRD, to pay the whole amount then remaining unpaid under
said Amended and Restated Guaranty, and interest thereon to date of payment,
whether the same shall be due or not, it being understood and agreed that upon
such sale before maturity of the Amended and Restated Guaranty the balance
thereof shall be immediately due and payable; FOURTH, to pay liens of record
against the security property according to their priority of lien and to the
extent that funds remaining in the hands of the Trustees are available; and
LAST, to pay the remainder of said proceeds, if any, to Grantor, its heirs,
personal representatives, successors or assigns upon the delivery and surrender
to the purchaser of possession of the said land and premises, less costs and
expenses of obtaining possession.

     7. That if the security property shall be advertised for sale, as
hereinabove provided, and not sold, Grantor will pay all costs in connection
therewith including, but not limited to advertising and attorney's fees, and all
other costs, including a reasonable Trustee's fee as provided in Section 6
hereof, and the same shall be secured in like manner as other charges and
expenses relating to the execution of this trust and bear interest at the rate
stated in said Amended and Restated Guaranty.

     8. That Grantor's obligations shall be made free and clear of, and without
deduction or withholding for or on account of, any present or future income,
stamp or other taxes, levies, imposts, duties, charges, fees, deductions, or
withholdings, now or hereafter imposed, levied, collected, withheld or assessed
by any court, or governmental body, agency, or other official, excluding certain
taxes, all as set forth more specifically in the Amended and Restated Guaranty.

     9. That Grantor warrants specially the property herein conveyed and that it
will execute such further assurances thereof as may be requisite.

     10. That the Grantor is not primarily liable for the debt secured hereby.

     11. That this Amended and Restated Indemnity Deed of Trust is in full
substitution of the Indemnity Deed of Trust by and between Grantor and Trustee
dated November 5, 2001, recorded among the Land Records of Montgomery County on
December 13, 2001 in Liber 20155, folio 346.

     The provisions of this Amended and Restated Deed of Trust shall be binding
upon and inure to the benefit of Grantor, its heirs, personal representatives,
successors and assigns, the Trustees and any successor, or substitute trustee or
trustees, and the holder of the Guaranty hereby secured. Whenever used herein,
the singular shall include the plural, the plural the singular, and the use of
any gender shall be applicable to all genders.

                                   [Signatures follow]

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     Witness the following signatures and seals.


Witnesses:                                        GRANTOR:

                                                  QIAGEN SCIENCES, INC.
         /s/ Cheryl Lindsay
-----------------------------------------



         /s/ Steve Pabst                          By: /s/ Michael W. Burgett
-----------------------------------------         --------------------------
                                                     Michael W. Burgett,
                                                     Vice President


Title Insurance: NA


STATE OF Maryland, County of Montgomery, to wit:
         --------            ----------

      I HEREBY CERTIFY, that on this 28th day of February, 2002, before me, the
subscriber, a Notary Public of the State aforesaid, personally appeared Michael
W. Burgett, who acknowledged himself to be the Vice President of the Grantor
corporation herein, and that he as such Vice President, being authorized so to
do, executed the foregoing instrument for the purposes therein contained by
signing, in my presence, the name of the said corporation by himself/herself as
Vice President.

     WITNESS my hand and Notarial Seal.

                                      /s/ Fredeke de Vazeille       (Seal)
                                      -----------------------
                                      Notary Public






     THIS IS TO CERTIFY that the within instrument was prepared by or under the
supervision of the undersigned, an attorney duly admitted to practice before the
Court of Appeals of Maryland.

                                    /s/ Stephen W. McVearry
                                    -----------------------------------
                                    Attorney












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