Ernst Boris Chain (1906-1979), German biochemist. Chain was educated in Germany, and emigrated to the UK in 1933 when Hitler came to power. His work covered a wide range of topics, including chemical pathology, phospholipids, snake venoms, methods of analysis and tumour metabolism. His most famous work, from 1939, was the reinvestigation of the therapeutic action of penicillin (discovered nine years earlier by Alexander Fleming). He shared the 1945 Nobel Prize in Physiology or Medicine for his work on penicillin (shared with his colleague in the penicillin investigations - Florey - and also shared with Fleming).