Born Feb. 21, 1866, in Bamberg; died Mar. 16, 1925, in Berlin. German microbiologist and immunologist. Studied in Strasbourg, Vienna, and Berlin.

From 1902, Wassermann was a professor at the R. Koch Institute for Infectious Diseases and, beginning in 1913, director of the Institute for Experimental Therapy in Berlin. His major investigations dealt with the study of the change in the blood serum of patients during the process of developing immunity to cholera, typhus, and diphtheria. In 1906 (in collaboration with A. Neisser and K. Brun) he devised a method for diagnosing syphilis—the Wassermann test. He established (1901) immunological specificity of the proteins of various animals and worked on the perfecting of the serodiagnosis of tuberculosis, tumors, and so on.