Robert Koch (rō´bĕrt kôkh), 1843–1910, German bacteriologist. He studied at Göttingen under Jacob Henle. As a country practitioner in Wollstein, Posen (now Wolsztyn, Poland), he devoted much time to microscopic studies of bacteria, for which he devised not only a method of staining with aniline dyes but also techniques of bacteriological culture still in general use. He established the bacterial cause of many infectious diseases and discovered the microorganisms causing anthrax (1876), wound infections (1878), tuberculosis (1882), conjunctivitis (1883), cholera (1884), and other diseases. He was professor at the Univ. of Berlin from 1885 to 1891 and head of the Institute for Infectious Diseases (founded for him) from 1891 to 1904. In the course of his bacteriological investigations for the British and German governments he traveled to South Africa, India, Egypt, and other countries and made valuable studies of sleeping sickness, malaria, bubonic plague, rinderpest, and other diseases. For his work in developing tuberculin as a test for tuberculosis he received the 1905 Nobel Prize in Physiology or Medicine.