August von Wassermann discovered a blood serum test that enabled doctors to find out if a patient had syphilis, a potentially lethal disease which, in some patients, has a very long latency period during which no symptoms are detectable.

Wassermann was born in Bamberg, Germany, on February 21, 1866, to Dora (Bauer) and Angelo Wassermann, a banker. He received his secondary education in Bamberg and studied medicine at several German and Austrian universities. Wassermann married Alice von Taussig in 1895. They had two sons. He received his M.D. degree in 1888 at the University of Strasbourg. In 1890, Wassermann began work at the Institute for Infectious Diseases in Berlin, which was directed by Robert Koch.

Although Wassermann did important work on tetanus, cholera, diphtheria, and tuberculosis, he is best known for his discovery of a blood serum test (now called the Wassermann test) that enabled doctors to find out if a patient...