New guidelines aimed at stopping companies making frivolous attempts to patent genes before they really have any use for them were issued by the US Patent and Trademark Office yesterday.
The rules were intended to help end what has become an acrimonious debate on patenting genes, a multimillion dollar business for many companies.
They put to rest any question about whether genes can be patented at all - making it clear that companies may indeed patent genes or even pieces of genes, though they may not patent mere genetic sequences.
"It's raised the bar," said Ms Brigid Quinn, a spokeswoman for the patent office. "You can patent a gene but you have to patent the gene with a use."
The guidelines are barely changed from interim rules issued a year ago, the patent office said. They leave biotech companies such as Rockville, Maryland-based Celera Genomics and Human Genome Sciences Inc. free to continue patenting genes they are racing to identify.
Ms Quinn said the new guidelines added another hurdle before anyone can get a patent on a range of technologies, but biotechnology is the industry most clearly affected.
To show "utility", an applicant had to prove that the discovery had credible and specific uses. Now they must also show that use is "substantial", Ms Quinn said.
"An example would be that genes express proteins and any protein could be an additive to dog food or shampoo," she said. "However, it would not meet the requirement of a substantial utility because in the real world people would not spend the enormous amounts of money to isolate the gene to put into dog food and shampoo."
Mr Paul Gilman, a senior executive at Celera, said this would have the effect of stopping companies from making up a possible use for a newly discovered gene and patenting it before they find out how it really works.
"They don't want you to sort of guess and say this patent covers everything in the universe," said Mr Gilman. owns nine patents on the BRCA1 and BRCA2 genes associated with breast cancer, anyone who discovered a whole new role or use for those genes could apply for a separate patent.
In the real world they usually cross-license, so each can use the other's application, Quinn said.
Arguments against the whole idea of patenting genes - based on the premise that genes are a part of nature and not an invention - were roundly rejected by the patent office.
The office also said the entire sequence of a gene does not have to be published for someone to patent it. "Describing the complete chemical structure, i.e. the DNA sequence, is one method of describing a DNA molecule but it is not the only method," it said.