PCR:
Taq Polymerase Patent Ruled Invalid
Robert F. Service
Seven years ago the Swiss pharmaceutical giant Hoffmann-La Roche sued Promega Corp., a small biochemicals supplier based in Madison, Wisconsin, for infringing a Roche patent on Taq polymerase, a crucial element of the standard technique used to replicate snippets of DNA. Last week a federal judge in San Francisco, California, ruled that the contested patent is invalid because its original holder, the now defunct Cetus Corp., obtained it by deliberately misleading the U.S. Patent and Trademark Office. The ruling means that, for now, Promega can continue to sell Taq without paying royalties to Roche.