In 1939, Australian scientist Howard Florey (later Baron Florey) and a team of researchers (Ernst Boris Chain, Arthur Duncan Gardner, Norman Heatley, M. Jennings, J. Orr-Ewing and G. Sanders) at the Sir William Dunn School of Pathology, University of Oxford made progress in showing the "in vivo" bactericidal action of penicillin.
=== Uporaba v zdravstvu ===Leta 1930 je Cecil George Paine, patolog v bolnišnici v Sheffildu, poskusil uporabiti penicilin pri zdravljenju stafilokokne okužbe lasnih mešičkov na bradi (sycosis barbae), vendar neuspešno.