The antisense patent infringement trial between Calgene Inc. and Enzo Biochem Inc. began last week in U.S. District Court in Delaware. In addition to the dispute's potential impact on CGNE's Flavr Savr tomato program, the case has implications for the way in which patents are written.

ENZ is the exclusive licensee of three U.S. patents - Nos. 5,190,931, 5,208,149 and 5,272,065 - issued in 1993 to the State University of New York. The patents contain claims covering the use of antisense technology in all cells, including plant cells. CGNE holds a patent - No. 5,107,065 - covering the use of antisense in plant cells.