Leslie A (Epstein) Falk (1915-2004) and penicillin production at Oxford

To establish penicillin as a unique chemotherapeutic agent, Howard Florey and his colleagues at the Sir William Dunn School of Pathology at Oxford University needed to produce it in significant amounts. The first attempts to grow Penicillium notatum for penicillin production were carried out by Florey's colleague, Ernst Chain, in association with an American Rhodes Scholar, Leslie A Epstein, beginning in 1939. Little has been known about this work except that some impure penicillin was obtained and shown to be non-toxic in mice. Epstein, who later changed his name to Falk, died in 2004 at the age of 89 years. In an extensive memoir covering his career, he has provided new information about this early work. An apparatus was constructed for large-scale growth of microorganisms, including P. notatum, on solid agar medium.