As she knew how to type, she obtained a part time position as secretary to Dr. Rudolf Schoenheimer, a leading biochemist at Columbia University's College of Physicians and Surgeons. Not believing that any good graduate school would admit and provide financial support to a woman Sussman studied stenography and took a job as a secretary to Michael Heidelberger, another biochemist at Columbia. She graduated from Hunter College in January 1941.
In mid-February she received an offer of a teaching assistantship in physics at the University of Illinois at Urbana-Champaign because World War II came up and many men went off to war and the university offered scholarships for women rather than close down. That summer she took two tuition-free physics courses under government auspices at New York University. At the University of Illinois, she was the only woman among the department's 400 members, and the first since 1917. She married fellow student Aaron Yalow in 1943, and received her Ph.D. in 1945. After graduating, Yalow joined the Bronx Veterans Administration Hospital to help set up its radioisotope service. There she collaborated with Solomon Berson to develop RIA, a radioisotope tracing technique that allows the measurement of tiny quantities of various biological substances in the blood. Originally used to study insulin levels in diabetes mellitus, the technique has since been applied to hundreds of other substances – including hormones, vitamins and enzymes – all previously too small to detect. Despite its huge commercial potential, Yalow and Berson refused to patent the method.
In 1975 Yalow and Berson received the AMA Scientific Achievement Award. The following year she became the first female recipient of the Albert Lasker Award for Basic Medical Research. In 1977 she received the Nobel Prize, together with Roger Guillemin and Andrew V. Schally. Berson had died in 1972, and so could not share the latter prizes. She received the National Medal of Science in 1988.