Melvin P. Klein, a biophysicist noted for applying advanced experimental techniques to biological problems, died suddenly at his home in Berkeley on Sunday, May 28. He was 78.

MEL KLEIN STUDIED PROTEINS USING AN ADVANCED LIGHT SOURCE BEAMLINE WHICH HE HELPED DESIGN AND BUILD. HE IS PICTURED WITH KAREN MCFARLANE.

Klein was a senior physicist, emeritus in the Physical Biosciences Division and a member of the Chemistry Department at UC Berkeley. At the time of his death he was actively pursuing research into the oxygen-evolving system in plants -- the source of the world's oxygen supply -- a field to which he had made fundamental contributions for the past quarter century.

Born in Denver in 1921, as a boy Klein was an enthusiastic gadgeteer -- by age 11 he was a ham radio operator. He studied engineering at the University of Denver, and during World War II he served as a civilian radio engineer for the Army Air Corps, the Office of War Information, the Harvard Radio Research Laboratory, and the intelligence section of Gen. Douglass MacArthur's forces in the Pacific.

At UC Berkeley after the war he concentrated on physics and biophysics after a year in medical school, and received his A.B. in 1952 and his Ph.D. in biophysics in 1958. Meanwhile, he joined the Lab, then known as the UC Radiation Laboratory.

While working on instrumentation for the Rad Lab's giant proton linear accelerator near Livermore in the early 1950s, he became interested in the phenomenon of nuclear magnetic resonance (NMR), which was yet to be applied to medical imaging. With a colleague he developed a digital computer-based signal averaging technique which, said Berkeley Lab Director Charles Shank, became "the sine qua non of modern Fourier transform NMR spectroscopy and has permeated most fields of experimental science."

After spending a year at Bell Labs in New Jersey, Klein returned to the Bay Area and in 1963 joined the laboratory run by Melvin Calvin on the Berkeley campus -- today's Calvin Lab -- where he was named senior staff scientist as part of Berkeley Lab's Chemical Biodynamics Division.

Except for brief sabbaticals (in Paris on a Guggenheim Fellowship in 1966-67 and in Berlin on a Humboldt Award in 1988-89), plus a very brief retirement in 1991, Klein devoted the rest of his career to biophysics in Berkeley.

Klein was a world-renowned leader in developing applications of NMR and many other measurement techniques to biophysical problems. Notable was his work on synchrotron-based x-ray spectroscopy. Klein was instrumental in establishing biological research facilities at Berkeley Lab's Advanced Light Source.

In announcing Klein's death, Graham Fleming, director of the Physical Biosciences Division, wrote, "Mel embodied the spirit of curiosity and interest in the world around him that marks a true scientist and an intellectual ... To say he will be terribly missed is an insufficient expression of our loss."

Klein's longtime collaborator on photosynthesis, Kenneth Sauer, said, "He was a gentle soul and at the same time a great teacher and leader who inspired students and postdocs and hundreds of good friends around the world."

In October 1998, in a special issue of the Journal of Physical Chemistry devoted to Klein and Sauer, their Berkeley Lab colleague Alexander Pines wrote that "Mel Klein has educated generations of students and postdocs, many of whom have gone on to stellar careers, and he has been and remains an enduring inspiration to us all. But Mel also has that rarest of human qualities, he is a mensch, a real mensch. Dear Mel ... you have earned our love and our respect."

Klein is survived by his wife of 40 years, Margaret, their daughter Adrienne, sons Mark and Peter, and two grandchildren.

A memorial service was held at the UC Berkeley Faculty Club on Friday, June 9.