YALOW, Rosalyn, née Sussman, American medical physicist/endocrinologist,   b-1921. On the staff of the Bronx Veterans Administration Hospital from 1947-91. Rosalyn mainly worked on  insulin measurement, a technique was needed that did not involve injection of isotopes into the patient. Yalow and Berson working together developed RIA (radioimmunoassay), a method for blood hormone assays. It was first used in 1959, but they did not patent it so that this vital technique became widely used and was not cost prohibitive. Rosalyn was awarded the 1977 Nobel Prize in Medicine for this vital technique now used in medical labs everywhere. It is highly specific because of the immunochemical reagents, and very sensitive because radioisotopes make minute amounts of hormone detectable and measurable. Rosalyn was only the second woman to win a Nobel in Medicine and the first American woman to win a Nobel in a science category. From 1972, she was a Senior Medical Investigator at the Veterans Administration, later a professor at Mount Sinai School of Medicine. In 1978 she became President of the Endocrine Society. A member of the NAS. Awarded the National Medal of Science in 1988.