Not all diseases manifest clearly recognizable physical symptoms, or by the time the symptoms are visible, it may be too late to successfully treat the illness. Early and accurate diagnosis of disease is essential to saving lives, and chemistry has played an important role in the historical development of diagnostic testing.
In the 1930s Esmond R. Long and Florence B. Seibert developed a better diagnostic test for the deadly lung infection tuberculosis (TB)—the PPD test, which is still the standard test in use today.
Helen and Alfred Free revolutionized diagnostic urine testing with their invention of a chemically coated paper dipstick that measures a patient’s blood sugar by changing color when dipped in a urine sample.
Rosalyn Yalow and Solomon Berson developed radioimmunoassay (RIA), a technique that uses radioactive materials to investigate the human body for tiny amounts of substances. RIA is especially important for the early detection of diseases.