After high school, Yalow was interested in biochemistry and physics, but didn’t think any good graduate school would allow a woman in. (One rejection came with this note: “She is from New York. She is Jewish. She is a woman.”) But with World War II starting up, the University of Illinois at Urbana-Champaign decided to offer scholarships to women rather than shut down when its students went off to fight. “I was told I was the first woman [in the Engineering Department] since 1917,” she said later. She received her PhD in nuclear physics in 1945, and went to work at the Veterans Administration Hospital in the Bronx to help improve diagnostic tests.
At the time, large quantities of blood was needed to detect the tiny amounts of substances, such as hormones, to get an accurate measurement. Yalow and her colleague, Dr. Solomon Berson, developed a new measurement technique: radioimmunoassay, or RIA. Their first target was insulin. RIA was a breakthrough, accurately measuring substances in the body with such great precision, only a few picograms of blood was needed. And, by the way, the tests could be done cheaply. Yalow and Berson later extended the method to work with many other substances, allowing, for example, blood banks to screen donations for hepatitis. In 1977, Yalow’s work was described as “a spectacular combination of immunology, isotope research, mathematics and physics” which “brought about a revolution in biological and medical research.” That’s what the Nobel Prize committee said, anyway: Yalow became the second woman in history to receive the Nobel Prize in Medicine. (Berson had died, and the Nobel is not awarded posthumously.) “This was pioneering work at the highest level,” the Nobel committee said. “We were witnessing the birth of a new era in endocrinology, one that started with Yalow.” And despite RIA’s commercial potential, Yalow and Berson refused to patent their method. Yalow died May 30 in the Bronx. She was 89.