Florence B. Seibert, American biochemist and academic (d. 1991)

Florence Barbara Seibert (October 6, 1897 – August 23, 1991) was an American biochemist. She is best known for identifying the active agent in the antigen tuberculin as a protein, and subsequently for isolating a pure form of tuberculin, purified protein derivative (PPD), enabling the development and use of a reliable TB test. Seibert has been inducted into the Florida Women's Hall of Fame and the National Women's Hall of Fame.