A daughter of the Bronx
Rosalyn Sussman was born on July 19, 1921, in the South Bronx, New York City. Her parents were Jewish; her father, Simon Sussman, ran a small paper-and-twine business and had been born on the Lower East Side, and her mother, Clara, had come from Germany as a child. Neither had finished high school, but both were determined that their two children would be educated, and books from the public library were a constant in the household. Rosalyn was, by her own cheerful account, stubborn and certain of herself from an early age, qualities she would need in full. She was drawn first to mathematics and then, as a teenager, to science. A high-school chemistry teacher kindled her interest, and reading a biography of Marie Curie fixed her ambition: she would be a scientist, and specifically a physicist, in an era when that path was effectively closed to women, and doubly so to a Jewish woman of modest means.
Hunter, and a stubborn ambition
Yalow attended Hunter College, the free college for women in New York City, where she was among the first students to major in physics. She graduated in 1941, but her professors gently told her the truth as they saw it: no good graduate school would admit a woman to study physics, still less fund her. One adviser suggested she become a secretary as a way to slip into a scientific laboratory through a side door, and she briefly took a course in stenography. Then history opened the door that prejudice had shut. The United States entered the Second World War, young men left the universities for the military, and graduate physics departments suddenly needed students. The University of Illinois offered Yalow a teaching assistantship. In 1941 she arrived to find herself the only woman among the hundreds of members of the College of Engineering’s faculty and teaching staff, the first, it was said, since 1917.
Illinois, and a partnership for life
At Illinois, Yalow worked at a furious pace, making up undergraduate physics courses she had never been offered while carrying a full graduate load and teaching. On her first day she met another physics student, Aaron Yalow, the son of a rabbi; they married in 1943. Theirs became a lifelong partnership, and the couple kept an observant Jewish home, raising two children with a kosher kitchen. Yalow saw no conflict whatever between rigorous science and religious tradition, and was proud of both. In 1945 she earned her doctorate in nuclear physics, one of the first women in the United States to do so. She returned to New York, taught physics for a time at Hunter, and then made the decisive move of her career: she joined the Bronx Veterans Administration Hospital, bringing the tools of nuclear physics, radioactive isotopes, into the service of medicine.
The Bronx VA, and Solomon Berson
At the VA hospital Yalow built a radioisotope laboratory almost from nothing, at first in a converted janitor’s closet. In 1950 she began the collaboration that would define her life’s work, with a young physician named Solomon Berson. The pairing was ideal: Yalow the physicist, expert in radioactivity and precise measurement; Berson the clinician, fluent in the body and its diseases. For more than two decades they worked in near-constant partnership, their thinking so intertwined that colleagues could not always tell where one mind ended and the other began. Together they began using tiny amounts of radioactive isotopes as tracers, labels that let them follow hormones and other substances through the body and measure how the body handled them. It was an unusual fusion of physics and medicine, and it was about to produce a discovery that would change clinical laboratories everywhere.
An inconvenient discovery
Studying how the body used insulin, Yalow and Berson found something unexpected and, at first, unwelcome to the medical establishment. They showed that adults treated with animal insulin developed antibodies to it, their immune systems recognised the foreign hormone and bound to it. This contradicted the prevailing belief that a molecule as small as insulin could not provoke an immune response, and a leading journal at first rejected their paper. Yalow and Berson stood their ground, and they were proved right. But the deeper significance lay in the method. They realised that the exquisitely specific way an antibody binds its target, combined with the extraordinary sensitivity of radioactive measurement, could be turned into a tool, a way to measure vanishingly small quantities of almost any biological substance in a simple sample of blood.
Radioimmunoassay
Out of that insight came radioimmunoassay, or RIA, which Yalow and Berson developed through the late 1950s. The principle was elegant: a known amount of radioactively labelled hormone competes with the unlabelled hormone in a patient’s blood sample for binding sites on a specific antibody, and by measuring the radioactivity one can calculate, with great precision, how much of the substance the sample contains. RIA was sensitive on a scale medicine had never before possessed, sensitive enough, in a much-repeated comparison, to detect the equivalent of a teaspoon of sugar dissolved in a large lake. For the first time, doctors could accurately measure hormones, vitamins, enzymes, viruses, and drugs present in the blood in almost infinitesimal amounts. It opened a hidden layer of the body’s chemistry to direct observation, and it transformed both diagnosis and research.
A gift left unpatented
Yalow and Berson made a deliberate choice that shaped how widely their discovery would spread: they did not patent radioimmunoassay. They could have done so, the technique was immensely valuable, and would underpin a global industry. Instead they published it openly and freely, so that any laboratory anywhere could adopt it without paying a license fee. Yalow was matter-of-fact about it: the point of the work was that it be used, and a patent would only have slowed its reach into the world’s hospitals. The decision placed her in notable company, alongside Jewish scientists such as Jonas Salk and Albert Sabin, who treated a medical breakthrough not as private property but as something owed to humanity. Within a few years RIA had spread to clinical laboratories around the world, and whatever personal fortune was forgone was repaid, by any humane measure, many times over in lives.
The Nobel Prize
Solomon Berson died suddenly in 1972, and Yalow, grief-stricken, threw herself into work, partly to secure the recognition she felt her partner deserved. She renamed the laboratory in his honour and resolved to prove that she could carry the work forward alone. She did. In 1977 Rosalyn Yalow was awarded the Nobel Prize in Physiology or Medicine for the development of radioimmunoassay, the second woman ever to win that prize, and the first American-born woman to win a Nobel in the sciences. Because the prize is not given posthumously, Berson could not share it; Yalow used her moment in the spotlight to honour him, again and again, in public. She was acutely aware of what her victory signified for others, and in her Nobel lectures and speeches she spoke directly about the obstacles women in science still faced, and about the waste of barring half of humanity from scientific work.
A champion for the next generation
Yalow had succeeded in spite of a system that had told her, plainly, that there was no place for her, and she spent the rest of her career making sure other women heard a different message. She mentored younger scientists, spoke and wrote tirelessly about women in science, and insisted, pointing to her own observant home and her decades-long marriage, that a woman need not choose between a family and a serious scientific career. She could be demanding and blunt, with exacting standards, but she was generous with those who shared her seriousness about the work. She held that talent is distributed without regard to sex, and that any society which discourages half its people from contributing is squandering a resource it cannot afford to lose. She continued working into old age, suffered a stroke, and died in the Bronx, the borough where she had been born and spent almost her whole life, on May 30, 2011, at eighty-nine.
Impact and legacy
Radioimmunoassay became one of the most important laboratory techniques of twentieth-century medicine, and its descendants are everywhere in modern healthcare. The method made it possible to screen donated blood for hepatitis, sharply reducing transfusion-transmitted infection; to diagnose thyroid disorders and problems of blood sugar; to detect hormonal imbalances and adjust treatment precisely; and to measure drug levels in the blood so that doses could be made safe. It became a foundation of the new field of endocrinology and a routine tool in laboratories on every continent, behind countless diagnoses every single day. Beyond the technique itself, Yalow left a second legacy as enduring as the first: the example of a poor girl from the Bronx, refused entry to science because of her sex and her background, who forced the door open, reached the highest honour her field could offer, and then spent her authority widening that door for everyone who came after her.
Sources & further reading
Rosalyn Yalow, Wikipedia · Researched from the sources above and checked against them. Spotted an error? Tell us.
A life of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.