An important culture of penicillium notatum, Sir Alexander Fleming, dated 1948

Sir Alexander Fleming (1881-1955) studied at St Mary's Hospital and, while Hunterian Professor at the Royal College of Surgeons, devoted himself to investigating the possibility of finding an effective antibiotic substance which would kill bacteria without harming cell tissue.  In 1928 he dicovered the germ killing properties of penicillium notatum but it was not until 1940 in Oxford that Ernst Chain and Howard Florey managed to Stabilise and purify penicillin for general use.

As supplies of penicillin expanded and its effect became more widely known, tributes and honours were showered on Alexander Fleming. He was elected to the fellowship of the Royal Society in 1943, knighted in 1944 and received the Nobel Prize for medicine, jointly with Chain and Florey, in 1945.