Blood tests are a powerful diagnostic tool that can allow doctors to detect diseases that may be lurking in the body. One of the most important types, called a radioimmunoassay, was developed in the 1950s by two researchers who stumbled upon the idea while conducting diabetes research.

A radioimmunoassay (RIA) test uses radioactive particles to detect diseases like hepatitis in the bloodstream. When it was invented, RIA was far more sensitive than any other blood test then available to doctors. Instead of looking for the disease itself, radioimmunoassay tests work by searching for the antibodies that the body produces to fight a disease—a telltale sign of infection.

The RIA was the brainchild of American physicians Solomon Berson (1918–1972) and Rosalyn Yalow (1921–), who were co-workers at a veteran’s hospital in the Bronx. The duo were seeking to solve a long-standing problem in diabetes treatment: When a patient was given animal insulin, the substance initially kept blood sugar low, but soon the patient’s body developed resistance to the animal hormone, weakening its effectiveness.

Yalow and Berson theorized that animal insulin must provoke an immune reaction in the body. If so, they realized, there would be antibodies in the bloodstream. To test this hypothesis, the devised the first RIA to look for antibodies and track the effects of animal insulin in the body.

The test helped them develop a better understanding of how the body responds to animal insulin. But it soon dawned on Berson and Yalow that the same method could be used to look for antibodies directed at many other kinds of molecules associated with other hormones, drugs, diseases and infections, and many other agents. Berson and Yalow published their results in 1959, opening up a breakthrough technology to the scientific community.

The RIA test may detect a recent or chronic infection because it can take weeks or months for antibodies to appear, and antibodies may still be present after an infection has passed. Radioimmunoassay remains helpful in many medical settings and in medical research, although numerous new technologies are being used as well.

ADDITIONAL FACTS

  1. Along with Andrew Schally (1926–) and Roger Guillemin (1924–), Rosalyn Yalow received the Nobel Prize in Physiology or Medicine in 1977 for pioneering work in the field of diabetes. Berson did not live to share the prize with her; he died of a heart attack in 1972.
  2. Berson and Yalow could have worked with any number of hormones in their early work, but they chose insulin because it was readily available and easy to work with—and possibly because Yalow’s husband had diabetes, which gave her a special interest in the research.
  3. Berson and Yalow never patented their invention. “Patents are about keeping things away from people for the purpose of making money,” Yalow explained. “We wanted others to be able to use [radioimmunoassay].”