Technicians refining penicillin in a laboratory, taken by James Jarche for Illustrated magazine in 1943. Penicillin is an antibiotic, a chemical effective at very low concentrations which can kill or stop the growth of a disease-causing microbe. Penicillin is produced naturally in moulds of the genus Penicillium, from where the drug gets its name. During WW2, Sir Howard Walter Florey and Ernst Boris Chain developed a means of producing penicillin on an industrial scale. Together with Alexander Fleming - who identified the antibacterial properties of the penicillium mould in 1928 - they shared the Nobel Prize in 1945. Their work on producing a 'wonder drug' saved millions of lives.
© NMeM / Daily Herald Archive / Science & Society Picture Library