Gen-Probe Inc., a company dedicated to using DNA probes asthe technological basis for its diagnostic assays, has suedMicroProbe Corp., another DNA probe diagnostic company, forinfringing its patent on probe technology.

On Monday, Gen-Probe (which is a wholly owned subsidiary ofthe Japanese company Chugai Pharmaceutical) filed a patentinfringement suit in the U.S. District Court in San Diego againstMicroProbe of Garden Grove, Calif., and Bothell, Wash., chargingMicroProbe with infringing its U.S. patent, No. 4,851,330, whichrelates to the detection, identification and quantification ofnon-viral organisms through the targeting of ribosomal RNAsequences. The suit alleges that MicroProbe's medicaldiagnostic kits target ribosomal RNA sequences and thereforedirectly infringe Gen-Probe's patent.

Gen-Probe is seeking damages and reasonable attorney's fees,as well as an injunction against MicroProbe's continuedmanufacture and sales of its kits. MicroProbe's currentlymarketed Affirm VP system is a direct DNA-probe test for in-office diagnosis of vaginitis. It's been on the market in the U.S.since October 1992.

MicroProbe said Tuesday that it has evaluated the Gen-Probepatent in light of prior art and believes that the claims areinvalid. "Gen-Probe's request for injunction is difficult tounderstand, particularly since none of our products infringe thepatent in question," said John Bishop, MicroProbe's chiefexecutive officer.

MicroProbe purportedly targets single-stranded stretches ofDNA rather than ribosomal RNA in its DNA (syntheticoligonucleotide) probes. But Gen-Probe "believes in fact thatMicroProbe's probes do target rRNA," said Hayden Trubitt, anattorney with Brobeck, Phleger & Harrison of San Diego, the lawfirm that is handling Gen-Probe's suit.

This is the second time that Gen-Probe has sued a competitorfor infringing its patented core technology. In 1992, MolecularBiosystems Inc. and its subsidiary, Syngene Inc., agreed thatGen-Probe's patent for targeting ribosomal RNA sequences wasvalid and stopped manufacturing, using and selling theinfringing products. They also paid Gen-Probe an undisclosedsum. That case took less than a year to resolve; it was settled"during the discovery stage," Trubitt told BioWorld.

"We have and will continue to aggressively protect our patentsfrom infringement," added Thomas Bologna, Gen-Probe'spresident and chief executive officer.

-- Jennifer Van Brunt Senior Editor

(c) 1997 American Health Consultants. All rights reserved.