Florence B. Seibert (1897 – 1991) was an American biochemist known for isolating a pure form of tuberculin used in the standard TB test. She is a member of the U.S. National Women’s Hall of Fame.
Born in Easton, Pennsylvania, Seibert is said to have read biographies of famous scientists as a teenager which inspired her interest in science. As a child she contracted polio which left her walking with a limp, though the disability did not interfere with her life or work.
Seibert did her undergraduate work at Goucher College and earned her Ph.D. in biochemistry from Yale University. At Yale she studied the intravenous injection of milk proteins under the direction of Lafayette Mendel. She developed a method to prevent these proteins from being contaminated with bacteria.
Seibert served as an instructor in pathology from 1924-28 at the University of Chicago and was hired as an assistant professor in biochemistry in 1928. At the University of Chicaco she developed a method for purifying the crystalline tuberculin derivative under the supervision of Esmond R. Long. This purified protein derivative (PPD) was used in the standard TB test. The previous tuberculin derivative, Koch’s substance, had produced false negative results in tuberculosis tests since the 1890s because of impurities in the material.
In 1932, she became assistant professor in biochemistry at the University of Pennsylvania at the Henry Phipps Institute and rose through the ranks to full professor and professor emeritus in 1959, when she retired.