Rosalyn Sussman Yalow

1921-

American Physicist

Rosalyn Sussman Yalow won the 1977 Nobel Prize for the development of radioimmunoassays for peptide hormones. The revolutionary radioimmunoassay (RAI) developed by Yalow and her colleague Solomon Berson (1918-1972) made possible the measurement of extremely minute amounts of almost any substance in blood and body tissues.

Yalow was born in New York City and has lived and worked there ever since, except for her graduate work at the University of Illinois. As a high school student, Yalow was interested in mathematics and chemistry, but at Hunter College she became attracted to nuclear physics. Like many other women scientists, Yalow was touched by Eve Curie's biography of her mother, Madame Curie, a book that Yalow still considers essential reading for aspiring female scientists.

Although Yalow hoped to become a physicist, in keeping with prevailing views of proper roles for women, her parents thought that a career as an elementary school teacher was a more practical goal. Indeed, few graduate programs in science were willing to accept a woman. During her senior year at Hunter, one of her physics professors suggested that she accept a position as secretary to Rudolf Schoenheimer at Columbia University's College of Physicians and Surgeons. Hopeful that this job would provide a "backdoor" entráe into graduate courses, Yalow agreed to take a course in stenography. Soon after she received her B.A. degree from Hunter College in 1941, Yalow was offered a teaching assistantship in physics from the University of Illinois. At the first meeting of the Faculty of the College of Engineering, she discovered that she was the only woman out of about 400 faculty members and students. Yalow considered her being hired an important achievement, but she realized that the draft of young men into the armed forces made the college more willing to admit women. Here, she met Aaron Yalow, another new graduate student in physics, and married him in 1943. Even though Yalow earned As in most of her courses, the chairman of the physics department told her than her A- in one laboratory course proved "women do not do well at laboratory work." She was awarded her M.S. in physics in 1942 and her Ph.D. in nuclear physics in 1945.

From 1945 to 1950, Yalow was a physics teacher and researcher at Hunter College. She also worked as a part-time consultant to the Radiotherapy Service at the Bronx Veterans Administration (VA) Hospital from 1947 until 1950, when she established a radioisotope laboratory at the Bronx VA Hospital. (She conducted full-time research here until 1980.) Soon after she founded the laboratory, she began a fruitful collaboration with Solomon A. Berson, who was a resident in internal medicine at the VA Hospital. Yalow and Berson worked together until his death in 1972. At Yalow's request, her laboratory was later designated the Solomon A. Berson Research Laboratory.

Their first investigations were in the application of radioisotopes to blood volume determination, clinical diagnosis of thyroid diseases, and the kinetics of iodine metabolism. They extended these techniques to studies of the distribution of globin, serum proteins, and small peptide hormones, such as insulin. Yalow and Berson used insulin that was tagged with radioactive iodine and injected it into diabetic and normal subjects. After discovering that insulin-treated patients developed antibodies to animal insulins, they realized that they had a tool that could potentially be used to measure insulin in the blood. Eventually, the concept was transformed into a practical methodology for the measurement of plasma insulin. Yalow and Berson named their technique, which they developed in 1959, the radioimmunoassay (RIA). The RIA made possible the measurement of virtually any substance of biological interest, such as antibodies, enzymes, hormones, or drugs, in blood and body tissues. (Often, these important factors are present in amounts that are too small for conventional direct measurements.) The RIA was eventually turned into a diagnostic kit that is routinely used to measure hundreds of substances of biological interest.

LOIS N. MAGNER