John B. Fenn, 93, who shared the 2002 Nobel Prize for chemistry for developing a technique that sped up the development of new drugs and the study of the molecules of life, died last Friday in Richmond, Va.

A spokeswoman for Virginia Commonwealth University in Richmond, where Mr. Fenn was a professor of chemistry, confirmed his death but did not provide information about its cause.

Mr. Fenn was in his 70s when he published the research that won the Nobel Prize, focusing on a new way to identify and map proteins, carbohydrates, DNA, and other large biological molecules. He shared the prize with Koichi Tanaka, an engineer in Kyoto, Japan, and Kurt Wuethrich, a professor of biophysics in Zurich, Switzerland, who worked independently on related protein research.

Mr. Fenn improved on a technique known as mass spectrometry, which identifies molecules like proteins by how quickly they are accelerated in an electric field. Using his approach, biologists can now identify molecules in a matter of seconds rather than weeks, speeding up research on new drugs.

Mr. Fenn and Yale University, where he had taught, battled over the patent rights to the technique he invented, electrospray ionization, after he personally patented it - contrary to university policy - and licensed it to a company he had cofounded. A federal judge ruled in 2005 that Mr. Fenn was guilty of "civil theft," assigned the patent to Yale, and ordered him to pay Yale more than $1 million. He appealed the ruling but lost.

- N.Y. Times News Service