Paul Ralph Ehrlich was a German #bacteriologist, #hematologist and #immunologist whose pioneering…

Paul Ralph Ehrlich was a German #bacteriologist, #hematologist and #immunologist whose pioneering work in #chemotherapy included the discovery of #Salvarsan (#arsphenamine), the first effective treatment for #syphilis against the #spirochete #Treponema #pallidum. His research in the histology of the blood established #hematology as a field. Ehrlich also developed new staining methods for microscopic studies on live #tissue. At a time when little was understood about the mechanism of disease caused by #bacteria, he proposed the side-chain theory as a chemical explanation of #immunity, the body's defenses against #infection. Though broadly incorrect, the theory nevertheless stimulated further work on the problem. He shared the 1908 #NobelPrize for #Physiology or #Medicine with Russian bacteriologist, Élie Metchnikoff.