Rosalyn Sussman Yalow
Rosalyn Sussman Yalow (1921–2011), a medical physicist, was a cowinner of the 1977 Nobel Prize in Physiology or Medicine—and the first American-born woman to receive that prize. She codeveloped a groundbreaking technique called radioimmunoassay, using radioactive isotopes to measure biological molecules with extreme precision. Yalow’s technique allowed many biochemical applications: understanding the nature of diabetes, measuring vitamins in blood samples, or screening out blood donations containing hepatitis B. She was a member of the National Academy of Sciences.