Exhibit 32.1

Certifications

Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

(Subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code)

In connection with the Quarterly Report of Genoptix, Inc., a Delaware corporation (the “Company”), on Form 10-Q for the period ended September 30, 2007, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Tina Nova Bennett, President and Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

1.The Report fully complies with the requirements of Section 13(a) or Section 15(d), as applicable, of the Securities Exchange Act of 1934, as amended; and

2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Dated: December 12, 2007	/s/ Tina Nova Bennett
	Tina Nova Bennett
	President and Chief Executive Officer
	(principal executive officer of the registrant)

In connection with the Report, I, Douglas A. Schuling, Senior Vice President and Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

1.The Report fully complies with the requirements of Section 13(a) or Section 15(d), as applicable, of the Securities Exchange Act of 1934, as amended; and

2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Dated: December 12, 2007	/s/ Douglas A. Schuling
	Douglas A. Schuling
	Senior Vice President and Chief Financial Officer
	(principal financial and accounting officer of the registrant)