Which Scottish scientist discovered the antibiotic penicillin in 1928?

The Scottish scientist who discovered the antibiotic penicillin in 1928 was Alexander Fleming. Fleming was working at St Mary’s Hospital in London when he noticed that a mould contaminating a bacterial culture had created a clear zone where bacteria could not grow.

The mould belonged to the genus Penicillium, and Fleming identified the antibacterial substance it released as “penicillin.” He published his findings in 1929, but the discovery did not immediately become a practical treatment. Fleming’s early preparations were difficult to purify and produce in large quantities.

A decade later, researchers at the University of Oxford—including Howard Florey, Ernst Chain, and their colleagues—developed methods to extract, concentrate, and test penicillin as a drug. Their work helped turn Fleming’s observation into a usable antibiotic. Fleming, Florey, and Chain shared the 1945 Nobel Prize in Physiology or Medicine.

A common mix-up is crediting Fleming alone for the entire medicine. Fleming made the original discovery, while the Oxford team played a crucial role in developing penicillin for clinical use and large-scale production.