AMENDED AND RESTATED INDEPENDENT CONTRACTOR AGREEMENT

Exhibit 10.3

AMENDED AND RESTATED INDEPENDENT CONTRACTOR AGREEMENT

FOR CONSULTING SERVICES

This Independent Contractor Agreement for Consulting Services (the “Agreement”), dated November 6, 2006 is entered into by and between NANOGEN, INC., a Delaware corporation (the “Company”) with its principal place of business at 10398 Pacific Center Court, San Diego, CA 92121 and HEINER DREISMANN (“Consultant”).

In consideration of having been retained as a consultant to the Company, and the compensation Consultant will receive from the Company from time to time, Consultant hereby agrees as follows:

1. The amount of time Consultant will spend as a Consultant to the Company, the nature of the services provided, Consultant’s compensation and Consultant’s social security number are set forth in Exhibit “A”. In rendering such services to the Company, Consultant will act as an independent contractor and not as an employee of the Company and will be free to devote to a third person that portion of Consultant’s time, energy and skill that Consultant has not agreed to devote to the Company; provided, however, that Consultant will not during the term hereof provide to any person or entity any services related to the subject matter or nature of the services to be provided hereunder without the prior written consent of the Company. The Company or Consultant may terminate this Agreement at any time upon thirty (30) days’ written notice to the other party, with or without cause.

2. Consultant understands that nothing in this Agreement is intended to, or should be construed to, create a partnership, agency, joint venture or employment relationship between the Company and Consultant. Consultant also understands that Consultant will not be entitled to any of the benefits which the Company may make available to its employees, including, but not limited to, group health or life insurance, profit sharing or retirement benefits. Consultant also understands that Consultant is not authorized to make any representation, contract or commitment on behalf of the Company unless specifically requested or authorized in writing to do so by the Company. Consultant will file, on a timely basis, all tax returns and payments required to be filed with, or made to, any federal, state or local tax authority with respect to the performance of services and receipt of fees under this Agreement. Consultant is solely responsible for, and must maintain adequate records of, expenses incurred in the course of performing services under this Agreement. No part of Consultant’s compensation will be subject to withholding by the Company for the payment of any social security, federal, state or any other employee payroll taxes. The Company will regularly report amounts paid to Consultant by filing Form 1099-MISC with the Internal Revenue Services as required by law.

3. Consultant understands the Company possesses and will continue to possess valuable information that has been created, discovered or developed, or has otherwise become known to the Company, including without limitation, information created, discovered or developed or made known by Consultant (and within the scope of this Agreement) or to Consultant during the period of or arising out of Consultants retention as a consultant by the Company, and/or in which property rights have been assigned or otherwise conveyed to the Company, which information has commercial value in the business in which the Company is engaged. All of this information is referred to as “Proprietary Information.” By way of illustration, but not limitation, Proprietary Information includes trade secrets, processes, formulae, scientific data and results, data and know-how, improvements, inventions, techniques, marketing plans, strategies and forecasts. Proprietary Information also includes information of third parties received by the Company under obligation of confidentiality.

4. All Proprietary Information will be the sole property of the Company and its assigns, and the Company and its assigns shall be the sole owner of all patents and other rights in connection therewith. Consultant hereby assigns to the Company any rights Consultant may have or acquire in all Proprietary Information. At all times while retained as a Consultant by the Company and at all times after termination of such retention as a Consultant, Consultant will keep in confidence and trust all Proprietary Information or anything relating to it and Consultant will not divulge any Proprietary Information to any third party or use Proprietary Information in any manner without the written consent of the Company.

5. Consultant agrees that during the period that Consultant is retained as a consultant to the Company, Consultant will not, without the Company’s express prior written consent, engage in an employment or activity (whether as a consultant, adviser or otherwise) in any business competitive with the Company.

6. All documents, data, records, apparatus, equipment and other physical property, whether or not pertaining to Proprietary Information, furnished to Consultant by the Company or produced by Consultant or others in connection with Consultant’s retention as a consultant will and remain the sole property of the Company and shall be returned promptly to the Company as and when requested by the Company. Should the Company not so request, Consultant will in any event return and deliver all such property upon termination of Consultant’s retention as a consultant by Consultant or by the Company for any reason and Consultant will not remove from the Company or retain any such property or any reproduction of such property upon such termination.

7. Consultant agrees that for a period of two (2) years following termination of the consulting relationship with the Company, Consultant will not solicit or in any manner encourage employees of the Company to leave its employ.

8. Consultant will promptly disclose to the Company, or any persons designated by the Company, all improvements, inventions, formulae, processes, techniques, know-how and data, whether or not patentable, made or conceived or reduced to practice or learned by Consultant, either alone or jointly with others, during the period of retention as a consultant which (a) result from tasks assigned Consultant by the Company, or (b) are funded by the Company, or (c) result from use of premises owned, leased or contracted for or by the Company (all said improvements, inventions, formulae, processes, techniques, know-how and data shall be collectively hereinafter called “Inventions”). Such disclosure shall continue for one (1) year after termination of this Agreement with respect to anything that would be an Invention if made, conceived, reduced to practice or learned during the term hereof; provided, however, that should this Agreement be terminated within the one year period commencing with the date of this Agreement, such disclosure will continue for six (6) months after termination of this Agreement.

9. Consultant agrees that all Inventions will be the sole property of the Company and its assigns, and the Company and its assigns will be the sole owner of all patents and other rights in connection therewith. Consultant hereby assigns to the Company any rights Consultant may have or acquire in all Inventions. Consultant further agrees as to all Inventions to assist the Company in every proper way (but at the Company’s expense) to obtain and from time to time enforce patents on the Inventions in any and all countries, and to that end Consultant will execute all documents for use in applying for and obtaining such patents thereon and enforcing same, as the Company may desire, together with any assignments thereof to the Company or persons designated by it. Consultant’s obligation to assist the Company in obtaining and enforcing patents for the Inventions in any and all countries will continue beyond the termination of Consultant’s retention as a consultant, but the Company will compensate Consultant at a reasonable rate commensurate with rates paid by others for comparable services after such termination for time actually spent by Consultant at the Company’s request on such assistance. In the event that the Company is unable for any reason whatsoever to secure Consultant’s signature to any lawful and necessary document required to apply for or execute any patent application with respect to an invention(s) (including renewals,