X0202 3 2006-12-15 0 0001383183 CombiMatrix Corp CBMX 0001044321 MARXE AUSTIN W & GREENHOUSE DAVID M C/O SPECIAL SITUATIONS FUNDS 527 MADISON AVENUE, SUITE 2600 NEW YORK NY 10022 0 0 1 0 Common Stock 3000000 I By Limited Partnerships Warrants 0.87 2006-12-15 2011-12-13 Common Stock 3600000 I By Limited Partnerships This is a joint filing by Austin W. Marxe (Marxe) and David M. Greenhouse (Greenhouse). They share voting and investment control over all securities owned by Special Situations Private Equity Fund, LP (PE) and Special Situations Life Science Fund, L.P. (LS). 2,000,000 shares of Common Stock are owned by PE and 1,000,000 shares of Common Stock are owned by LS. The interest of Marxe and Greenhouse in the shares of Common Stock owned by PE and LS is limited to the extent of his pecuniary interest. This is a joint filing by Austin W. Marxe (Marxe) and David M. Greenhouse (Greenhouse). They share voting and investment control over all securities owned by Special Situations Private Equity Fund, LP (PE) and Special Situations Life Science Fund, L.P. (LS). 2,400,000 Warrants are owned by PE and 1,200,000 Warrants are owned by LS. The interest of Marxe and Greenhouse in the shares of Warrants owned by PE and LS is limited to the extent of his pecuniary interest. Austin W. Marxe 2006-12-29 David M. Greenhouse 2006-12-29