PLEDGE AS COLLATERAL ON QUOTA OF A LIMITED-LIABILITY COMPANY

A.

The Debtor and each party listed as an “Investor” on the schedule of Investors (collectively, “ Investors ”) attached hereto as Annex A are parties to that certain securities purchase agreement, entered into in New York, United States of America, on August 26, 2007 (the “ Existing Securities Purchase Agreement ” and as amended by the Exchange Agreements defined below, the “ Securities Purchase Agreement ”), pursuant to which, among other things, the Collateral Agent purchased from the Debtor certain convertible notes (the “ Original Notes ”);

B.

The Debtor and each of the Investors entered into an amendment and exchange agreement in New York, United States of America, on March 13, 2008 (the “ First Exchange Agreement ”), pursuant to which the Debtor and each Investor, among other things, exchanged a portion of such Investor’s Original Notes for the Debtor’s 9.75% Senior Secured Convertible Notes (the “ Exchanged Notes ”), and the Debtor entered into a security agreement, dated March 13, 2008 (the “ Existing Security Agreement ” and together with any ancillary documents related thereto, collectively the “ Existing Security Documents ”), for the benefit of the Collateral Agent, whereby the Existing Notes are secured by a first priority, perfected security interest in certain of the assets of the Debtor and its subsidiaries;

C.

The Debtor and each of the Investors entered into a Second Amendment and Exchange Agreements in New York, on August 14, 2008, (collectively, the “ Second Exchange Agreements ” and together with the First Exchange Agreements, the “ Exchange Agreements ”), pursuant to which, among other things, the Debtor and each Investor have agreed to (i) exchange its Exchanged Notes for the “ Amended Exchanged Notes ” (as defined in the Second Exchange Agreements) and (ii) issue the “ Additional Exchanged Notes ” (as defined in the Second Exchange Agreements) (and as such Amended Exchanged Notes together with the Additional Exchanged Notes may be amended, restated, replaced or otherwise modified from time to time in accordance with the terms thereof, collectively, each a “ Note ” and collectively, the “ Notes ”), conditional, among other things, to the execution and the delivery by the Debtor of a pledge agreement providing for the grant of a second priority perfected security interest in the entire quota held by the Debtor in the Company (as defined below) to secure all the Debtor’s obligations under the Notes, the Securities Purchase Agreement and certain other Transaction Documents (as defined below);

D.

On August 15, 2008 (“ Issuance Date ”), the Debtor issued in New York, United States of America, the Notes for the payment to the order of the Investors or any of their successors or assignees (“ Holder ”) of: (i) the principal amount of up to US$ 16.245.224,98 (as increased pursuant to the addition of any unpaid and capitalized interest in accordance with the Notes and as reduced pursuant to the terms of the Notes pursuant to redemption, conversion or otherwise, the “ Principal ”), when due, whether upon the Maturity Date (as defined below), acceleration, redemption or otherwise, in each case in accordance with the terms of the Notes; (ii) interest at the applicable rate, as defined in the Notes, not exceeding 15 % per annum (or, if lower, the maximum non-usurious rate permitted by Law n. 108/1996 or by any other applicable Italian law), computed on the basis of a 360-day year comprised of twelve 30-day months, on any outstanding Principal from the Issuance Date until the same becomes due and payable, whether upon an Interest Date (as defined below) or the Maturity Date, acceleration, conversion, redemption, amortization or otherwise (“ Interest ”); (iii) Late Charges (as defined below) on any past due and delinquent sums, both principal and interest; (iv) actual out-of-pocket expenses, including counsel fees and court costs in case of delayed payment of any Principal amount and Interest, and payment of tax indemnities and fiscal charges incurred by the Holder in connection with the collection of the Notes (the “ Expenses ”). Other than as specifically permitted by the Notes, the Debtor may not prepay any portion of the outstanding Principal, accrued and unpaid Interest or accrued and unpaid Late Charges, if any, on Principal and Interest;

E.

The Debtor holds a quota having a total face value of Euros 50.000,00 representing a 100% stake in the share capital of Nanogen Advanced Diagnostic S.r.l. (the “Quota” which term shall also indicate, for the purposes hereof, all new quotas as may be issued from time to time by the Company owned by the Pledgor, to which the Second Italian Pledge over Quota [as defined below] shall be extended by virtue of this agreement), a limited liability company incorporated under the laws of Italy, having registered share capital of Euros 50.000,00 and share capital subscribed and paid in of Euros 50.000,00, registered in the Companies Registry at n. 05239350969, Italian tax payer code n. 05239350969, with registered offices in 20090 Trezzano sul Naviglio (MI), Via C. Colombo 49, Italy, ( “Company” ). By virtue of the “ Contratto di Costituzione di Pegno su Quota di Società a Responsabilità Limitata ”, dated as of September 15, 2008, the Debtor has granted a first priority pledge over the Quota to Portside Growth & Opportunity Fund, as Collateral Agent appointed by Portside Growth and Opportunity Fund, Capital Ventures International, Enable Opportunity Partners LP, Pierce Diversified Strategy Master Fund LLC, Enable Growth Partners LP, Highbridge International LLC, Castlerigg Master Investments Ltd, Financière Elitech SAS (the “ First Investors ” and/or the “ First Secured Creditors ”) for the benefit of the First Secured Creditors (the “ First Italian Pledge over Quota ”);

F.

The Investors have appointed the Collateral Agent as their agent for obtaining and managing a second priority security interest over the Quota. The Collateral Agent is authorized to obtain – in its own name—the transcription in the Company’s quotaholders book of the second priority pledge over the Quota;

G.

By virtue of a security agreement entered into by and between the Debtor and the Collateral Agent, in New York, United States of America, on August 14, 2008, (“ Amended and Restated Security Agreement ”), the Debtor granted to the Collateral Agent for the benefit of the Secured Parties a second priority security interest in, among other things, the Quota, as collateral security for all the Debtor’s obligations under the Notes, the Securities Purchase Agreement and the Amended and Restated Security Agreement;

H.

In relation to the foregoing, the Pledgor intends to establish a valid, effective and perfected second priority pledge, pursuant to Italian Law, over the Quota (such security interest hereinafter the “ Second Italian Pledge over Quota ”) together and jointly in favour of the Collateral Agent for the benefit of the Secured Parties and as collateral for the Guaranteed Claims (as defined below).

I.

Since a first priority pledge over the Quota has already been granted to the Collateral Agent as security for certain promissory notes (as described in the Second Exchange Agreements) pursuant to the First Italian Pledge over Quota, the Collateral Agent, by virtue of the Intercreditor Agreement (as defined below), has agreed to subordinate the Second Italian Pledge over Quota to the First Italian Pledge over Quota.

1.

RECITALS AND DEFINITIONS

1.1

The preceding Recitals and the Annexes A, B and C attached hereto constitute a substantial and essential part of this agreement.

1.2

Should the context so require, the terms defined in the singular shall have the same significance when used in the plural, and vice-versa.

1.3

The headings of the articles were inserted solely to facilitate consultation and are not to be understood as having the effect of provisions and must not be taken into consideration for purposes of interpreting the provisions hereof.

1.4

Unless the context requires differently, any reference in this agreement to:

(a)

an Article, Paragraph or Annex shall be understood as a reference to an article, paragraph or annex to or of this agreement;

(b)

a law or regulation or regulatory provision shall be understood as a reference to said law or regulation or regulatory provision as subsequently amended or supplemented;

(c)

a party or another person shall be understood as a reference to said party or said person and to their respective successors or assignees;

(d)

a contract, act or document shall be understood as a reference to said contract, act or document with all modifications made or to be made thereto from time to time.

1.5

In this agreement:

(a)

the Debtor’s failure to pay to the Holder any cash amount of Principal (including, without limitation, any redemption payments), Interest due in cash, Late Charges or any other amounts due in cash when and as due under the Notes or any other Transaction Document, except, in the case of a failure to pay Interest and Late Charges when and as due, only if such failure continues for a period of fifteen (15) Business Days after written notice of such failure;

(b)

any other event or circumstance set forth in Section 4(a) of the Notes.

(a)

any claim for the payment of the Principal, Interest, Late Charges, and Expenses as defined herein; in addition to

(b)

any claim for the reimbursement of expenses, commissions, fees, discharge costs, compensation for damages and other indemnities, and for the payment of tax indemnities and fiscal charges, deriving from this agreement, the Amended and Restated Security Agreement, the Securities Purchase Agreement, including, without limitations, those arising pursuant to Section 4(a) and Section 4(b) thereof;

(c)

any other claim for the due performance and observance of the other obligations set forth in Section 3 of the Amended and Restated Security Agreement.

2.

PLEDGE AS COLLATERAL ON QUOTA OF COMPANY

2.1

The Pledgor hereby irrevocably pledges, together and jointly to the Collateral Agent for the benefit of the Secured Parties, the Quota – this term shall also indicate, for the purposes hereof, all dividends, sums of money, option rights, rights of conversion, exchange, and any other right, asset or benefit from time to time attributed, to be attributed or otherwise received or receivable, in relation to or in exchange for the Quota, including all such rights as may be attributed or received by virtue of, or in connection with, increases or reductions of the stated share capital of the Company, mergers and/or demergers of the Company or any extraordinary structural change affecting the share capital of the Company, as well as any profit or revenue deriving from the foregoing, including any revenue or fee for any disposal of the Quota, part thereof and/or of the rights associated therewith—as collateral for the Guaranteed Claims (the “Second Italian Pledge over Quota ” )

2.2

The Collateral Agent hereby acknowledges and accepts that the Second Italian Pledge over Quota is a second priority pledge which is subordinated to the First Italian Pledge over Quota and, therefore, that all such rights as are provided to the benefit of the Collateral Agent herein, including, without limitation, the rights set forth in Articles 8, 9, 10, 11, 12 of this agreement, are subject to the prior satisfaction in full of the rights of the First Secured Creditors and may not be exercised without the prior written consent of the First Secured Creditors.

2.3

It is understood that if and when the First Italian Pledge over Quota loose its effectiveness for any reason, including, without limitation, the discharge or the waiver thereof, the Second Italian Pledge over Quota will become a first priority pledge and the provisions set forth in Article 2.2. shall cease to have effect.

3.

GUARANTEED CLAIMS

3.1

Subject to Article 2.2., the Second Italian Pledge over Quota secures—without previous recourse by the Collateral Agent against the Debtor or any issuer of another personal guaranty or collateral security—the Guaranteed Claims both collectively and individually.

3.2

Without prejudice to any provisions set forth in this agreement regarding the enforcement of the Second Italian Pledge over Quota, it is expressly agreed that the Second Italian Pledge over Quota may be enforced on all or part of the assets it encumbers, in order to obtain the performance of each of the Guaranteed Claims at its respective due date, at the discretion of the Collateral Agent.

4.

PLEDGE REMAINING EFFECTIVE

4.1

As an explicit exception to Article 1200 of the Civil Code, the First Italian Pledge over Quota shall remain valid in its entirety, notwithstanding any repayment or partial performance of the Guaranteed Claims until the expiration of the Period of Effectiveness. In the event we have not received a security claim from you regarding the Quota prior to the expiration of the Period of Effectiveness, the Second Italian Pledge over Quota shall be deemed for all purposes terminated and without further force and effect.

4.2

If the Second Italian Pledge over Quota is considered for any reason discharged prior to the expiration of the Period of Effectiveness, it shall be renewed by the Pledgor in the event that each or any payment or satisfaction, by or on behalf of the Debtor, or any other means of discharging the Guaranteed Claims, has been revoked by a competent bankruptcy court pursuant to an action of fraudulent conveyance.

4.3

Subject to Article 2.2, the Second Italian Pledge over Quota is absolute and additional to any other personal guaranty or collateral security from which the Collateral Agent is, at present or in the future, benefiting or come to benefit in relation to all or any one of the Guaranteed Claims.

5.

PERFECTION OF THE PLEDGE AS COLLATERAL ON QUOTA

5.1

The Pledgor undertakes to:

5.1.1.  

procure this agreement to be recorded in good time, also paying any relevant tax in connection therewith;

5.1.2.  

procure this agreement to be filed in good time with the Companies Registry kept by the competent Chamber of Commerce in relation to the Company for the registration provided for by art. 2740 of the Italian Civil Code;

5.1.3.  

within five Business days from the knowledge of the registration described in Paragraph 5.1.2, cause the Second Italian Pledge over Quota to be noted in the Company’s share ledger according to the form established in Annex B;

5.1.4.  

upon completion thereof, deliver to the Collateral Agent a true copy or an abstract of the pages of the Company’s share ledger showing said annotation, whose conformity to the original shall be certified by a Notary Public.

6.

PLEDGOR’S REPRESENTATIONS AND WARRANTIES

6.1

The Pledgor represents and warrants the following to the Collateral Agent:

6.1.1  

the Pledgor is a duly incorporated and existing company under the Laws of Delaware; the signing and execution of this agreement fall within the scope of its corporate object and all such corporate or other decisions as are required so that:

6.1.2  

as of this day the Pledgor is not subject (nor is it threatened to be subject) to any liquidation proceeding, pre-bankruptcy settlement, administrative procedure that may (i) prevent the Pledgor from the regular pursuit of its corporate object or from the business activities, as currently carried out by the Pledgor itself, or (ii) establish or involve any restriction of the rights of the Pledgor’s creditors or (iii) prevent or render unenforceable the signing of this agreement and the establishment and perfection of the collateral envisaged herein.

6.2

The Pledgor further represents and warrants the following to the Collateral Agent:

6.2.1  

the Pledgor is the sole legitimate and exclusive owner of the Quota, and has full and valid title thereto; the Quota is free from any encumbrance, collateral and, save only for Article 5 of its by-laws, right of option or first refusal, or any other lien or right of third parties, save only for the First Italian Pledge over Quota and the collateral security created hereby and hereunder, and securities or liens as may be created or granted directly and exclusively by operation of law; the Quota is not subject to distraints or attachments or other restrictive measure and is freely transferable;

6.2.2  

the Company is a duly incorporated and existing limited liability company under Italian Law and, save only for Article 5 of its by-laws, its charter and by-laws do not provide for any right of first refusal or other restrictions that may prevent or limit the exercise and enforcement of the pledge rights hereunder;

6.2.3  

as of this date the Company is not subject (nor is it threatened to be subject) to any liquidation proceeding, pre-bankruptcy settlement, administrative procedure that, in any case, may (i) prevent the Company from the regular pursuit of its corporate object or from the business activities, as currently carried out by the Company itself, or (ii) establish or involve any restrict