Ehrlich, Paul (1854–1915)

German bacteriologist and immunologist who was awarded a Nobel Prize for Physiology or Medicine in 1908 with Ilya Mechnikov for their work on immunity. He produced the first cure for syphilis, developing the arsenic compounds, in particular Salvarsan, that were used in the treatment of syphilis before the discovery of antibiotics.

Ehrlich founded chemotherapy – the use of a chemical substance to destroy disease organisms in the body. He was also one of the earliest workers on immunology, and through his studies on blood samples the discipline of haematology was recognized.

Ehrlich was born in Strehlin, Silesia (now Strzelin, Poland). He studied at Breslau, Strasbourg, and Leipzig. In 1884 he became a professor in Berlin, but spent 1886–88 in Egypt, curing himself of tuberculosis contracted in the course of research. He set up a small private laboratory in Berlin in 1889, in addition to his academic posts.

Ehrlich teamed up with bacteriologists Emil von Behring and Shibasaburō Kitasato to try to find a cure for diphtheria. Ehrlich had studied antigen–antibody reactions using toxic plant proteins on mice, and Behring and Ehrlich were able to produce antitoxins obtained from much larger mammals which had been immunized against the diphtheria organism. These antitoxins were concentrated and purified, and successfully used on children in 1894.

The search progressed to dyes that would stain only bacteria and not other cells, and from this research Ehrlich's staff continued synthesizing and testing chemical substances that could seek out and destroy the bacteria without harming the human body. Ehrlich termed these compounds ‘magic bullets’. This was how the cure for syphilis was found.