Exhibit 10.7

AMENDED AND RESTATED

1997
STOCK INCENTIVE PLAN OF

NANOGEN, INC.

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TABLE OF CONTENTS

|            |  |                                                               |  | Page
|----------- |  | ------------------------------------------------------------- |  | ----
|ARTICLE 1.  |  | INTRODUCTION                                                  |  | 1   
|ARTICLE 2.  |  | ADMINISTRATION                                                |  | 1   
|2.1         |  | Committee Composition                                         |  | 1   
|2.2         |  | Committee Responsibilities                                    |  | 1   
|ARTICLE 3.  |  | SHARES AVAILABLE FOR GRANTS                                   |  | 2   
|3.1         |  | Basic Limitation                                              |  | 2   
|3.2         |  | Additional Shares                                             |  | 2   
|3.3         |  | Dividend Equivalents                                          |  | 2   
|ARTICLE 4.  |  | ELIGIBILITY                                                   |  | 2   
|4.1         |  | General Rules                                                 |  | 2   
|4.2         |  | Outside Directors                                             |  | 2   
|4.3         |  | Incentive Stock Options                                       |  | 2   
|ARTICLE 5.  |  | OPTIONS                                                       |  | 2   
|5.1         |  | Stock Option Agreement                                        |  | 2   
|5.2         |  | Number of Shares                                              |  | 3   
|5.3         |  | Exercise Price                                                |  | 3   
|5.4         |  | Exercisability and Term                                       |  | 3   
|5.5         |  | Effect of Change in Control                                   |  | 3   
|5.6         |  | Modification or Assumption of Options                         |  | 3   
|5.7         |  | Other Requirements Prior to Company's Initial Public Offering |  | 3   
|ARTICLE 6.  |  | PAYMENT FOR OPTION SHARES                                     |  | 3   
|6.1         |  | General Rule                                                  |  | 3   
|6.2         |  | Surrender of Stock                                            |  | 4   
|6.3         |  | Exercise/Sale                                                 |  | 4   
|6.4         |  | Exercise/Pledge                                               |  | 4   
|6.5         |  | Promissory Note                                               |  | 4   
|6.6         |  | Other Forms of Payment                                        |  | 4   
|ARTICLE 7.  |  | STOCK APPRECIATION RIGHTS                                     |  | 4   
|7.1         |  | SAR Agreement                                                 |  | 4   
|7.2         |  | Number of Shares                                              |  | 4   
|7.3         |  | Exercise Price                                                |  | 4   
|7.4         |  | Exercisability and Term                                       |  | 4   
|7.5         |  | Effect of Change in Control                                   |  | 5   
|7.6         |  | Exercise of SARs                                              |  | 5   
|7.7         |  | Modification or Assumption of SARs                            |  | 5   
|ARTICLE 8.  |  | RESTRICTED SHARES AND STOCK UNITS                             |  | 5   
|8.1         |  | Time, Amount and Form of Awards                               |  | 5   
|8.2         |  | Payment for Awards                                            |  | 5   
|8.3         |  | Vesting Conditions                                            |  | 5   
|8.4         |  | Form and Time of Settlement of Stock Units                    |  | 5   
|8.5         |  | Death of Recipient                                            |  | 6   
|8.6         |  | Creditors' Rights                                             |  | 6   
|ARTICLE 9.  |  | VOTING AND DIVIDEND RIGHTS                                    |  | 6   
|9.1         |  | Restricted Shares                                             |  | 6   
|9.2         |  | Stock Units                                                   |  | 6   
|ARTICLE 10. |  | PROTECTION AGAINST DILUTION                                   |  | 6   
|10.1        |  | Adjustments                                                   |  | 6   
|10.2        |  | Reorganizations                                               |  | 6   
|ARTICLE 11. |  | AWARDS UNDER OTHER PLANS                                      |  | 7   

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|ARTICLE 12. |  | PAYMENT OF DIRECTOR'S FEES IN SECURITIES                    |  | 7 
|----------- |  | ----------------------------------------------------------- |  | --
|12.1        |  | Effective Date                                              |  | 7 
|12.2        |  | Elections to Receive NSOs, Restricted Shares or Stock Units |  | 7 
|12.3        |  | Number and Terms of NSOs, Restricted Shares or Stock Units  |  | 7 
|ARTICLE 13. |  | LIMITATION ON RIGHTS                                        |  | 7 
|13.1        |  | Retention Rights                                            |  | 7 
|13.2        |  | Stockholders' Rights                                        |  | 7 
|13.3        |  | Regulatory Requirements                                     |  | 7 
|ARTICLE 14. |  | LIMITATION ON PAYMENTS                                      |  | 8 
|14.1        |  | Gross-Up Payment                                            |  | 8 
|14.2        |  | Determination by Accountant                                 |  | 8 
|14.3        |  | Underpayments and Overpayments                              |  | 8 
|14.4        |  | Related Corporations                                        |  | 8 
|ARTICLE 15  |  | WITHHOLDING TAXES                                           |  | 9 
|15.1        |  | General                                                     |  | 9 
|15.2        |  | Share Withholding                                           |  | 9 
|ARTICLE 16. |  | ASSIGNMENT OR TRANSFER OF AWARDS                            |  | 9 
|16.1        |  | General                                                     |  | 9 
|16.2        |  | Trusts                                                      |  | 9 
|ARTICLE 17. |  | FUTURE OF THE PLAN                                          |  | 9 
|17.1        |  | Term of the Plan                                            |  | 9 
|17.2        |  | Amendment or Termination                                    |  | 9 
|ARTICLE 18. |  | DEFINITIONS                                                 |  | 9 
|ARTICLE 19. |  | EXECUTION                                                   |  | 12

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AMENDED AND RESTATED        1997 STOCK INCENTIVE PLAN OF        NANOGEN, INC.

ARTICLE 1. INTRODUCTION

The Plan was adopted by the Board effective as of August 1, 1997, and was approved by the Company's stockholders as of August 1, 1997. The Plan
is effective as of August 1, 1997. However, Articles 7, 8 and 9 shall not apply prior to the Company's initial public offering on April 14, 1998. The Plan was subsequently
(a) amended and restated on June 30, 1999 to increase the number of shares available for issuance under the Plan in Section 3.1; (b) amended on April 14, 2000 for
options issued on and after that date, to increase the period during which such options may be exercised after the death or disability of a Plan Participant to twelve months in Section 5.4;
(c) amended and restated on June 6, 2000 to increase the number of shares available for issuance under the Plan in Section 3.1 to 4,508,760; and (d) amended and restated on
June 13, 2001 to increase the number of shares available for issuance under the Plan in Section 3.1 to its current number.

The
purpose of the Plan is to promote the long-term success of the Company and the creation of stockholder value by (a) encouraging Key Employees to focus on
critical long-range objectives, (b) encouraging the attraction and retention of Key Employees with exceptional qualifications and (c) linking Key Employees directly to
stockholder interests through increased stock ownership. The Plan seeks to achieve this purpose by providing for Awards in the form of Restricted Shares, Stock Units, Options (which may constitute
incentive stock options or nonstatutory stock options) or stock appreciation rights.

The
Plan shall be governed by, and construed in accordance with, the laws of the State of California.

ARTICLE 2. ADMINISTRATION

2.1Committee Composition.The Plan shall be administered by the Committee. Except as provided below,
the Committee shall consist exclusively of directors of the Company, who shall be appointed by the Board. In addition, the composition of the Committee shall satisfy:



The
Board may act on its own behalf with respect to Outside Directors and may also appoint one or more separate committees composed of one or more officers of the Company who need not be directors of
the Company and who need not satisfy the foregoing requirements, who may administer the Plan with respect to Key Employees who are not "covered employees" under section 162(m)(3) of the Code
and who are not required to report pursuant to § 16(a) of the Exchange Act.

2.2Committee Responsibilities.The Committee shall (a) select the Key Employees who are to
receive Awards under the Plan, (b) determine the type, number, vesting requirements and other features and conditions of such Awards, (c) interpret the Plan and (d) make all other
decisions relating to the operation of the Plan. The Committee may adopt such rules or guidelines as it deems appropriate to implement the Plan. The Committee's determinations under the Plan shall be
final and binding on all persons.

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ARTICLE 3. SHARES AVAILABLE FOR GRANTS

3.1Basic Limitation.Common Shares issued pursuant to the Plan may be authorized but unissued shares
or treasury shares. The aggregate number of Common Shares available for Restricted Shares, Stock Units, Options and SARs awarded under the Plan shall not exceed 6,008,760. Of the Common Shares
available hereunder, no more than 25% in aggregate shall be available with respect to Outside Directors. The limitation of this Section 3.1 shall be subject to adjustment pursuant to
Article 10. The number of Common Shares available under this Plan shall be increased by unexercised or forfeited Common Shares under the Company's 1993 and 1995 Stock Plans.

3.2Additional Shares.If Stock Units, Options or SARs are forfeited or if Options or SARs terminate
for any other reason before being exercised, then the corresponding Common Shares shall again become available for Awards under the Plan. If Restricted Shares are forfeited before any dividends have
been paid with respect to such Shares, then such Shares shall again become available for Awards under the Plan. If Stock Units are settled, then only the number of Common Shares (if any) actually
issued in settlement of such Stock Units shall reduce the number available under Section 3.1 and the balance shall again become available for Awards under the Plan. If SARs are exercised, then
only the number of Common Shares (if any) actually issued in settlement of such SARs shall reduce the number available under Section 3.1 and the balance shall again become available for Awards
under the Plan.

3.3Dividend Equivalents.Any dividend equivalents distributed under the Plan shall not be applied
against the number of Restricted Shares, Stock Units, Options or SARs available for Awards, whether or not such dividend equivalents are converted into Stock Units.

ARTICLE 4. ELIGIBILITY

4.1General Rules.Only Key Employees (including, without limitation, independent contractors who are
not members of the Board) shall be eligible for designation as Participants by the Committee.

4.2Outside Directors.The Committee may provide that the NSOs that otherwise would be granted to an
Outside Director under this Plan shall instead be granted to an affiliate of such Outside Director. Such affiliate shall then be deemed to be an Outside Director for purposes of the Plan, provided
that the service-related vesting and termination provisions pertaining to the NSOs shall be applied with regard to the service of the Outside Director.

4.3Incentive Stock Options.Only Key Employees who are common-law employees of the
Company, a Parent or a Subsidiary shall be eligible for the grant of ISOs. In addition, a Key Employee who owns more than 10% of the total combined voting power of all classes of outstanding stock of
the Company or any of its Parents or Subsidiaries shall not be eligible for the grant of an ISO unless the requirements set forth in section 422(c)(6) of the Code are satisfied.

ARTICLE 5. OPTIONS

5.1Stock Option Agreement.Each grant of an Option under the Plan shall be evidenced by a Stock Option
Agreement between the Optionee and the Company. Such Option shall be subject to all applicable terms of the Plan and may be subject to any other terms that are not inconsistent with the Plan. The
Stock Option Agreement shall specify whether the Option is an ISO or an NSO. The provisions of the various Stock Option Agreements entered into under the Plan need not be identical. Options shall be
granted in consideration of services rendered to the Company or a Subsidiary. A Stock Option Agreement may provide that a new Option will be granted automatically to the Optionee when he or she
exercises a prior Option and pays the Exercise Price in the form described in Section 6.2.

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5.2Number of Shares.Each Stock Option Agreement shall specify the number of Common Shares subject to
the Option and shall provide for the adjustment of such number in accordance with Article 10. Options granted to any Optionee in a single calendar year shall in no event cover more than 750,000
Common Shares, subject to adjustment in accordance with Article 10.

5.3Exercise Price.Each Stock Option Agreement shall specify the Exercise Price; provided that the
Exercise Price under an ISO shall in no event be less than 100% of the Fair Market Value of a Common Share on the date of grant and the Exercise Price under an NSO shall in no event be less than the
par value of the Common Shares subject to such NSO. In the case of an NSO, a Stock Option Agreement may specify an Exercise Price that varies in accordance with a predetermined formula while the NSO
is outstanding, provided that prior to the Company's initial public offering, the NSO Exercise Price shall be at least 85% (110% for 10% shareholders) of the Fair Market Value of a Common Share of
Stock on the date of grant.

5.4Exercisability and Term.Each Stock Option Agreement shall specify the date when all or any
installment of the Option is to become exercisable, provided that prior to the Company's initial public offering, Options shall become exercisable pursuant to a schedule providing for at least 20%
vesting per year over a five-year period (or, in the case of performance options, to the extent permitted under applicable regulations of the California Department of Corporations). The
Stock Option Agreement shall also specify the term of the Option; provided that the term of an ISO shall in no event exceed 10 years from the date of grant. A Stock Option Agreement may provide
for accelerated exercisability in the event of the Optionee's death, disability or retirement or other events and may provide for expiration prior to the end of its term in the event of the
termination of the Optionee's service.

Options
may be awarded in combination with SARs, and such an Award may provide that the Options will not be exercisable unless the related SARs are forfeited. NSOs may also be awarded
in combination with Restricted Shares or Stock Units, and such an Award may provide that the NSOs will not be exercisable unless the related Restricted Shares or Stock Units are forfeited.

Options
must be exercised within 90 days of the termination of employment (twelve months for termination on account of death or disability).

5.5Effect of Change in Control.The Committee may determine, at the time of granting an Option or
thereafter, that such Option shall become fully exercisable as to all Common Shares subject to such Option in the event that a Change in Control occurs with respect to the Company.

5.6Modification or Assumption of Options.Within the limitations of the Plan, the Committee may
modify, extend or assume outstanding options or may accept the cancellation of outstanding options (whether granted by the Company or by another issuer) in return for the grant of new options for the
same or a different number of shares and at the same or a different exercise price. The foregoing notwithstanding, no modification of an Option shall, without the consent of the Optionee, alter or
impair his or her rights or obligations under such Option.

5.7Other Requirements Prior to Company's Initial Public Offering.Prior to the Company's initial
public offering, Optionees shall receive Company financial statements at least annually.

ARTICLE 6. PAYMENT FOR OPTION SHARES

6.1General Rule.The entire Exercise Price of Common Shares issued upon exercise of Options shall be
payable in cash at the time when such Common Shares are purchased, except as follows:



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6.2Surrender of Stock.To the extent that this Section 6.2 is applicable, payment for all or
any part of the Exercise Price may be made with Common Shares which have already been owned by the Optionee for more than six months. Such Common Shares shall be valued at their Fair Market Value on
the date when the new Common Shares are purchased under the Plan.

6.3Exercise/Sale.To the extent that this Section 6.3 is applicable, payment may be made by the
delivery (on a form prescribed by the Company) of an irrevocable direction to a securities broker approved by the Company to sell Common Shares and to deliver all or part of the sales proceeds to the
Company in payment of all or part of the Exercise Price and any withholding taxes.

6.4Exercise/Pledge.To the extent that this Section 6.4 is applicable, payment may be made by
the delivery (on a form prescribed by the Company) of an irrevocable direction to pledge Common Shares to a securities broker or lender approved by the Company, as security for a loan, and to deliver
all or part of the loan proceeds to the Company in payment of all or part of the Exercise Price and any withholding taxes.

6.5Promissory Note.To the extent that this Section 6.5 is applicable, payment may be made with
a full-recourse promissory note; provided that the par value of the Common Shares shall be paid in cash.

6.6Other Forms of Payment.To the extent that this Section 6.6 is applicable, payment may be
made in any other form that is consistent with applicable laws, regulations and rules.

ARTICLE 7. STOCK APPRECIATION RIGHTS

7.1SAR Agreement.Each grant of an SAR under the Plan shall be evidenced by an SAR Agreement between
the Optionee and the Company. Such SAR shall be subject to all applicable terms of the Plan and may be subject to any other terms that are not inconsistent with the Plan. The provisions of the various
SAR Agreements entered into under the Plan need not be identical. SARs may be granted in consideration of a reduction in the Optionee's other compensation.

7.2Number of Shares.Each SAR Agreement shall specify the number of Common Shares to which the SAR
pertains and shall provide for the adjustment of such number in accordance with Article 10. SARs granted to any Optionee in a single calendar year shall in no event pertain to more than 300,000
Common Shares, subject to adjustment in accordance with Article 10.

7.3Exercise Price.Each SAR Agreement shall specify the Exercise Price. An SAR Agreement may specify
an Exercise Price that varies in accordance with a predetermined formula while the SAR is outstanding.

7.4Exercisability and Term.Each SAR Agreement shall specify the date when all or any installment of
the SAR is to become exercisable. The SAR Agreement shall also specify the term of the SAR. An SAR Agreement may provide for accelerated exercisability in the event of the Optionee's death, disability
or retirement or other events and may provide for expiration prior to the end of its term in the event of the termination of the Optionee's service. SARs may also be awarded in combination with
Options, Restricted Shares or Stock Units, and such an Award may provide that the SARs will not be exercisable unless the related Options, Restricted Shares or Stock Units are forfeited. An SAR may be
included in an ISO only at the time of grant but may be included in an NSO at the time of grant or thereafter. An SAR granted under the Plan may provide that it will be exercisable only in the event
of a Change in Control.

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7.5Effect of Change in Control.The Committee may determine, at the time of granting an SAR or
thereafter, that such SAR shall become fully exercisable as to all Common Shares subject to such SAR in the event that a Change in Control occurs with respect to the Company.

7.6Exercise of SARs.The exercise of an SAR shall be subject to the restrictions imposed by
Rule 16b-3 (or its successor) under the Exchange Act, if applicable. If, on the date when an SAR expires, the Exercise Price under such SAR is less than the Fair Market Value on
such date but any portion of such SAR has not been exercised or surrendered, then such SAR shall automatically be deemed to be exercised as of such date with respect to such portion. Upon exercise of
an SAR, the Optionee (or any person having the right to exercise the SAR after his or her death) shall receive from the Company (a) Common Shares, (b) cash or (c) a combination of
Common Shares and cash, as the Committee shall determine. The amount of cash and/or the Fair Market Value of Common Shares received upon exercise of SARs shall, in the aggregate, be equal to the
amount by which the Fair Market Value (on the date of surrender) of the Common Shares subject to the SARs exceeds the Exercise Price.

7.7Modification or Assumption of SARs.Within the limitations of the Plan, the Committee may modify,
extend or assume outstanding SARs or may accept the cancellation of outstanding SARs (whether granted by the Company or by another issuer) in return for the grant of new SARs for the same or a
different number of shares and at the same or a different exercise price. The foregoing
notwithstanding, no modification of an SAR shall, without the consent of the Optionee, alter or impair his or her rights or obligations under such SAR.

ARTICLE 8. RESTRICTED SHARES AND STOCK UNITS

8.1Time, Amount and Form of Awards.Awards under the Plan may be granted in the form of Restricted
Shares, in the form of Stock Units, or in any combination of both. Restricted Shares or Stock Units may also be awarded in combination with NSOs or SARs, and such an Award may provide that the
Restricted Shares or Stock Units will be forfeited in the event that the related NSOs or SARs are exercised.

8.2Payment for Awards.To the extent that an Award is granted in the form of newly issued Restricted
Shares, the Award recipient, as a condition to the grant of such Award, shall be required to pay the Company in cash an amount equal to the par value of such Restricted Shares. To the extent that an
Award is granted in the form of Restricted Shares from the Company's treasury or in the form of Stock Units, no cash consideration shall be required of the Award recipients.

8.3Vesting Conditions.Each Award of Restricted Shares or Stock Units shall become vested, in full or
in installments, upon satisfaction of the conditions specified in the Stock Award Agreement. A Stock Award Agreement may provide for accelerated vesting in the event of the Participant's death,
disability or retirement or other events. The Committee may determine, at the time of making an Award or thereafter, that such Award shall become fully vested in the event that a Change in Control
occurs with respect to the Company.

8.4Form and Time of Settlement of Stock Units.Settlement of vested Stock Units may be made in the
form of (a) cash, (b) Common Shares or (c) any combination of both, as determined by the Committee. The actual number of Stock Units eligible for settlement may be larger or
smaller than the number included in the original Award, based on predetermined performance factors. Methods of converting Stock Units into cash may include (without limitation) a method based on the
average Fair Market Value of Common Shares over a series of trading days. Vested Stock Units may be settled in a lump sum or in installments. The distribution may occur or commence when all vesting
conditions applicable to the Stock Units have been satisfied or have lapsed, or it may be deferred to any later date. The amount of a deferred distribution may be increased by an interest factor or by
dividend

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equivalents. Until an Award of Stock Units is settled, the number of such Stock Units shall be subject to adjustment pursuant to Article 10.

8.5Death of Recipient.Any Stock Units Award that becomes payable after the recipient's death shall be
distributed to the recipient's beneficiary or beneficiaries. Each recipient of a Stock Units Award under the Plan shall designate one or more beneficiaries for this purpose by filing the prescribed
form with the Company. A beneficiary designation may be changed by filing the prescribed form with the Company at any time before the Award recipient's death. If no beneficiary was designated or if no
designated beneficiary survives the Award recipient, then any Stock Units Award that becomes payable after the recipient's death shall be distributed to the recipient's estate.

8.6Creditors' Rights.A holder of Stock Units shall have no rights other than those of a general
creditor of the Company. Stock Units represent an unfunded and unsecured obligation of the Company, subject to the terms and conditions of the applicable Stock Award Agreement.

ARTICLE 9. VOTING AND DIVIDEND RIGHTS

9.1Restricted Shares.The holders of Restricted Shares awarded under the Plan shall have the same
voting, dividend and other rights as the Company's other stockholders. A Stock Award Agreement, however, may require that the holders of Restricted Shares invest any cash dividends received in
additional Restricted Shares. Such additional Restricted Shares shall be subject to the same conditions and restrictions as the Award with respect to which the dividends were paid. Such additional
Restricted Shares shall not reduce the number of Common Shares available under Article 3.

9.2Stock Units.The holders of Stock Units shall have no voting rights. Prior to settlement or
forfeiture, any Stock Unit awarded under the Plan may, at the Committee's discretion, carry with it a right to dividend equivalents. Such right entitles the holder to be credited with an amount equal
to all cash dividends paid on one Common Share while the Stock Unit is outstanding. Dividend equivalents may be converted into additional Stock Units. Settlement of dividend equivalents may be made in
the form of cash, in the form of Common Shares, or in a combination of both. Prior to distribution, any dividend equivalents which are not paid shall be subject to the same conditions and restrictions
as the Stock Units to which they attach.

ARTICLE 10. PROTECTION AGAINST DILUTION

10.1Adjustments.In the event of a subdivision of the outstanding Common Shares, a declaration of a
dividend payable in Common Shares, a declaration of a dividend payable in a form other than Common Shares in an amount that has a material effect on the price of Common Shares, a combination or
consolidation of the outstanding Common Shares (by reclassification or otherwise) into a lesser number of Common Shares, a recapitalization, a spinoff or a similar occurrence, the Committee shall make
such adjustments as it, in its sole discretion, deems appropriate in one or more of (a) the number of Options, SARs, Restricted Shares and Stock Units available for future Awards under
Article 3, (b) the limitations set forth in Sections 5.2 and 7.2, (c) the number of NSOs to be granted to Outside Directors under Section 4.2, (d) the number of
Stock Units included in any prior Award which has not yet been settled, (e) the number of Common Shares covered by each outstanding Option and SAR or (f) the Exercise Price under each
outstanding Option and SAR. Except as provided in this Article 10, a Participant shall have no rights by reason of any issue by the Company of stock of any class or securities convertible into
stock of any class, any subdivision or consolidation of shares of stock of any class, the payment of any stock dividend or any other increase or decrease in the number of shares of stock of any class.

10.2Reorganizations.In the event that the Company is a party to a merger or other reorganization,
outstanding Options, SARs, Restricted Shares and Stock Units shall be subject to the agreement of merger or reorganization. Such agreement may provide, without limitation, for the

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assumption of outstanding Awards by the surviving corporation or its parent, for their continuation by the Company (if the Company is a surviving corporation), for accelerated vesting and accelerated
expiration (provided the Company has previously had its initial public offering), or for settlement in cash.

ARTICLE 11. AWARDS UNDER OTHER PLANS

The Company may grant awards under other plans or programs. Such awards may be settled in the form of Common Shares issued under this Plan. Such Common Shares
shall be treated for all purposes under the Plan like Common Shares issued in settlement of Stock Units and shall, when issued, reduce the number of Common Shares available under Article 3.

ARTICLE 12. PAYMENT OF DIRECTOR'S FEES IN SECURITIES

12.1Effective Date.No provision of this Article 12 shall be effective unless and until the
Board has determined to implement such provision.

12.2Elections to Receive NSOs, Restricted Shares or Stock Units.An Outside Director may elect to
receive his or her annual retainer payments and meeting fees from the Company in the form of cash, NSOs, Restricted Shares, Stock Units, or a combination thereof, as determined by the Board. Such
NSOs, Restricted Shares and Stock Units shall be issued under the Plan. An election under this Article 12 shall be filed with the Company on the prescribed form.

12.3Number and Terms of NSOs, Restricted Shares or Stock Units.The number of NSOs, Restricted Shares
or Stock Units to be granted to Outside Directors in lieu of annual retainers and meeting fees that would otherwise be paid in cash shall be calculated in a manner determined by the Board. The terms
of such NSOs, Restricted Shares or Stock Units shall also be determined by the Board.

ARTICLE 13. LIMITATION ON RIGHTS

13.1Retention Rights.Neither the Plan nor any Award granted under the Plan shall be deemed to give
any individual a right to remain an employee, consultant or director of the Company, a Parent or a Subsidiary. The Company and its Parents and Subsidiaries reserve the right to terminate the service
of any employee, consultant or director at any time, with or without cause, subject to applicable laws, the Company's certificate of incorporation and by-laws and a written employment
agreement (if any).

13.2Stockholders' Rights.A Participant shall have no dividend rights, voting rights or other rights
as a stockholder with respect to any Common Shares covered by his or her Award prior to the issuance of a stock certificate for such Common Shares. No adjustment shall be made for cash dividends or
other rights for which the record date is prior to the date when such certificate is issued, except as expressly provided in Articles 8, 9 and 10.

13.3Regulatory Requirements.Any other provision of the Plan notwithstanding, the obligation of the
Company to issue Common Shares under the Plan shall be subject to all applicable laws, rules and regulations and such approval by any regulatory body as may be required. The Company reserves the right
to restrict, in whole or in part, the delivery of Common Shares pursuant to any Award prior to the satisfaction of all legal requirements relating to the issuance of such Common Shares, to their
registration, qualification or listing or to an exemption from registration, qualification or listing.

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ARTICLE 14. LIMITATION ON PAYMENTS

14.1Gross-Up Payment.In the event that it is determined that any payment or transfer by
the Company under the Plan to or for the benefit of (the "Payment") would be subject to the excise tax imposed by section 4999 of the Code or any interest or penalties with respect to such
excise tax (such excise tax, together with any such interest or penalties, are collectively referred to as the "Excise Tax"), then the Participant shall be entitled to receive an additional payment (a
"Gross-Up Payment") in an amount that shall fund the payment by the Participant of any Excise Tax on the Payment as well as all income taxes imposed on the Gross-Up Payment,
any Excise Tax imposed on the Gross-Up Payment and any interest or penalties imposed with respect to taxes on the Gross-Up Payment or any Excise Tax.

14.2Determination by Accountant.All mathematical determinations and all determinations of whether any
of the Payments are "parachute payments" (within the meaning of section 280G of the Code) including all determinations of whether a Gross-Up Payment is required, of the amount of
such Gross-Up Payment and of amounts determined under § 14.3 shall be made by the independent auditors most recently selected by the Board (the "Auditors"), which shall provide
its determination (the "Determination"), together with detailed supporting calculations regarding the amount of any Gross-Up Payment and any other relevant matters, both to the Company and
to the Participant within seven business days of the Participant's termination date, if applicable, or such earlier time as is requested by the Company or by the Participant (if the Participant
reasonably believes that any of the Total Payments may be subject to the Excise Tax). If the Accounting Firm determines that no Excise Tax is payable by the Participant, it shall furnish the
Participant with a written statement that the Auditors have concluded that no Excise Tax is payable (including the reasons therefor) and that the Participant has substantial authority not to report
any Excise Tax on the Participant's federal income tax return. If a Gross-Up Payment is determined to be payable, it shall be paid to the Participant within five business days after the
Determination is delivered to the Company or the Participant. Any determination by the Auditors shall be binding upon the Company and the Participant, absent manifest error.

14.3Underpayments and Overpayments.As a result of uncertainty in the application of
section 4999 of the Code at the time of the initial determination by the Auditors hereunder, it is possible that Gross-Up Payments not made by the Company should have been made
("Underpayments") or that Gross-Up Payments will have been made by the Company which should not have been made ("Overpayments"). In either event, the Auditors shall determine the amount of
the Underpayment or Overpayment that has occurred. In the case of an Underpayment, the amount of such Underpayment shall promptly be paid by the Company to or for the benefit of the Employee. In the
case of an Overpayment, the Employee shall, at the direction and expense of the Company, take such steps as are reasonably necessary (including the filing of returns and claims for refund), follow
reasonable instructions from, and procedures established by, the Company and otherwise reasonably cooperate with the Company to correct such Overpayment;provided,
however,that (i) the Employee shall in no event be obligated to return to the Company an amount greater than the net after-tax portion of the Overpayment
that the Employee has retained or has recovered as a refund from the applicable taxing authorities and (ii) this
provision shall be interpreted in a manner consistent with the intent of this Article 14, which is to make the Employee whole, on an after-tax basis, for the application of the
Excise Tax, it being understood that the correction of an Overpayment may result in the Employee's repaying to the Company an amount which is less than the Overpayment.

14.4Related Corporations.For purposes of this Article 14, the term "Company" shall include
affiliated corporations to the extent determined by the Auditors in accordance with section 280G(d)(5) of the Code.

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ARTICLE 15. WITHHOLDING TAXES

15.1General.To the extent required by applicable federal, state, local or foreign law, a Participant
or his or her successor shall make arrangements satisfactory to the Company for the satisfaction of any withholding tax obligations that arise in connection with the Plan. The Company shall not be
required to issue any Common Shares or make any cash payment under the Plan until such obligations are satisfied.

15.2Share Withholding.The Committee may permit a Participant to satisfy all or part of his or her
withholding or income tax obligations by having the Company withhold all or a portion of any Common Shares that otherwise would be issued to him or her or by surrendering all or a portion of any
Common Shares that he or she previously acquired. Such Common Shares shall be valued at their Fair Market Value on the date when taxes otherwise would be withheld in cash. Any payment of taxes by
assigning Common Shares to the Company may be subject to restrictions, including any restrictions required by rules of the Securities and Exchange Commission.

ARTICLE 16. ASSIGNMENT OR TRANSFER OF AWARDS

16.1General.An Award granted under the Plan shall not be anticipated, assigned, attached, garnished,
optioned, transferred or made subject to any creditor's process, whether voluntarily, involuntarily or by operation of law, except as approved by the Committee. Notwithstanding the foregoing, ISOs
and, prior to the Company's initial public offering, NSOs may not be transferable. However, this Article 16 shall
not preclude a Participant from designating a beneficiary who will receive any outstanding Awards in the event of the Participant's death, nor shall it preclude a transfer of Awards by will or by the
laws of descent and distribution.

16.2Trusts.Neither this Article 16 nor any other provision of the Plan shall preclude a
Participant from transferring or assigning Restricted Shares to (a) the trustee of a trust that is revocable by such Participant alone, both at the time of the transfer or assignment and at all
times thereafter prior to such Participant's death, or (b) the trustee of any other trust to the extent approved in advance by the Committee in writing. A transfer or assignment of Restricted
Shares from such trustee to any person other than such Participant shall be permitted only to the extent approved in advance by the Committee in writing, and Restricted Shares held by such trustee
shall be subject to all of the conditions and restrictions set forth in the Plan and in the applicable Stock Award Agreement, as if such trustee were a party to such Agreement.

ARTICLE 17. FUTURE OF THE PLAN

17.1Term of the Plan.The Plan, as set forth herein, was adopted as of August 1, 1997, and
became effective August 1, 1997, except that Articles 7, 8 and 9 shall not be effective prior to the date of the Company's initial public offering on April 14, 1998. The Plan shall
remain in effect until it is terminated under Section 17.2, except that no ISOs shall be granted after July 31, 2007.

17.2Amendment or Termination.The Board may, at any time and for any reason, amend or terminate the
Plan. An amendment of the Plan shall be subject to the approval of the Company's stockholders only to the extent required by applicable laws, regulations or rules. No Awards shall be granted under the
Plan after the termination thereof. The termination of the Plan, or any amendment thereof, shall not affect any Award previously granted under the Plan.

ARTICLE 18. DEFINITIONS

18.1  "Award" means any award of an Option, an SAR, a Restricted Share or a Stock Unit under the Plan.

18.2  "Board"
means the Company's Board of Directors, as constituted from time to time.

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18.3  "Change in Control" shall mean the occurrence of any of the following events:



The
term "Change in Control" shall not include the Company's initial public offering or a transaction, the sole purpose of which is to change the state of the Company's incorporation.

18.4  "Code"
means the Internal Revenue Code of 1986, as amended.

18.5  "Committee"
means a committee of the Board, as described in Article 2.

18.6  "Common
Share" means one share of the common stock of the Company.

18.7  "Company"
means Nanogen, Inc., a Delaware corporation.

18.8  "Exchange
Act" means the Securities Exchange Act of 1934, as amended.

18.9  "Exercise
Price," in the case of an Option, means the amount for which one Common Share may be purchased upon exercise of such Option, as specified in the
applicable Stock Option Agreement. "Exercise Price," in the case of an SAR, means an amount, as specified in the applicable SAR Agreement, which is subtracted from the Fair Market Value of one Common
Share in determining the amount payable upon exercise of such SAR.

18.10  "Fair
Market Value" means the market price of Common Shares, determined by the Committee as follows:



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Whenever
possible, the determination of Fair Market Value by the Committee shall be based on the prices reported in the Western Edition ofThe Wall Street
Journal. Such determination shall be conclusive and binding on all persons.

18.11  "ISO"
means an incentive stock option described in section 422(b) of the Code.

18.12  "Key
Employee" means (a) a common-law employee of the Company, a Parent or a Subsidiary, (b) an Outside Director and (c) a
consultant or adviser who provides services to the Company, a Parent or a Subsidiary as an independent contractor. Service as an Outside Director or as an independent contractor shall be considered
employment for all purposes of the Plan, except as provided in Sections 4.2 and 4.3.

18.13  "NSO"
means a stock option not described in sections 422 or 423 of the Code.

18.14  "Option"
means an ISO or NSO granted under the Plan and entitling the holder to purchase one Common Share.

18.15  "Optionee"
means an individual or estate who holds an Option or SAR.

18.16  "Outside
Director" shall mean a member of the Board who is not a common-law employee of the Company, a Parent or a Subsidiary.

18.17  "Parent"
means any corporation (other than the Company) in an unbroken chain of corporations ending with the Company, if each of the corporations other than the
Company owns stock possessing 50% or more of the total combined voting power of all classes of stock in one of the other corporations in such chain. A corporation that attains the status of a Parent
on a date after the adoption of the Plan shall be considered a Parent commencing as of such date.

18.18  "Participant"
means an individual or estate who holds an Award.

18.19  "Plan"
means this 1997 Stock Incentive Plan of Nanogen, Inc., as amended from time to time.

18.20  "Restricted
Share" means a Common Share awarded under the Plan.

18.21  "SAR"
means a stock appreciation right granted under the Plan.

18.22  "SAR
Agreement" means the agreement between the Company and an Optionee which contains the terms, conditions and restrictions pertaining to his or her SAR.

18.23  "Stock
Award Agreement" means the agreement between the Company and the recipient of a Restricted Share or Stock Unit which contains the terms, conditions and
restrictions pertaining to such Restricted Share or Stock Unit.

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18.24  "Stock Option Agreement" means the agreement between the Company and an Optionee which contains the terms, conditions and restrictions pertaining to his or her
Option.

18.25  "Stock
Unit" means a bookkeeping entry representing the equivalent of one Common Share, as awarded under the Plan.

18.26  "Subsidiary"
means any corporation (other than the Company) in an unbroken chain of corporations beginning with the Company, if each of the corporations other
than the last corporation in the unbroken chain owns stock possessing 50% or more of the total combined voting power of all classes of stock in one of the other corporations in such chain. A
corporation that attains the status of a Subsidiary on a date after the adoption of the Plan shall be considered a Subsidiary commencing as of such date.

ARTICLE 19. EXECUTION

To
record the adoption of the Plan by the Board, the Company has caused its duly authorized officer to affix the corporate name and seal hereto.

| |  | NANOGEN, INC.
| |  | -------------
| |  | By:          

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ADDENDUM TO NANOGEN, INC. 1997 STOCK INCENTIVE PLAN

For Option Agreements entered into with Participants who are either resident in the United Kingdom or employed by a United Kingdom
subsidiary of Nanogen, Inc., the following provisions are in addition to Article 15 ("Withholding Taxes"):

15.3(a)Compliance with United Kingdom Tax Laws.In addition to the tax
withholding requirements set forth in clause 15.1 above, the Participant will be subject to the deduction, withholding and payment of all amounts required to be deducted in the United Kingdom
under the provisions of the Pay As You Earn scheme (PAYE) and National Insurance. The Participant herby agrees that (a) the Participant is solely responsible for any (i) employee taxes
to Inland Revenue, (ii) employer taxes to National Insurance, and (iii) any other taxes due to any other United Kingdom taxing authority in connection with any stock options the
Participant may receive as a result of employment with Nanogen, whether upon receipt of options, vesting, exercise or sale of stock; (b) Nanogen may withhold and pay any such taxes pursuant to
Article 15.1; (c) the Participant will indemnify Nanogen in connection with any such payments; and (d) Nanogen may retain or delay transfer of any shares and/or options under
Article 15.1 until the Participant has confirmed the payment of all taxes due.

15.3(b)Survival.The above Article 15.3 (a) and
sub-clauses shall (a) survive the Participant's employment by Nanogen; (b) inure to the benefit of successors and assigns of Nanogen; and (c) be binding upon the
Participant's heirs and legal representatives for the relevant statutory period for payment of such taxes.

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