Glaxo crystalline penicillin and hypodermic needle, 1947.

UNITED KINGDOM - FEBRUARY 20: In 1928 Alexander Fleming (1881-1955), a Scottish researcher, discovered the bacteria-killing properties of a substance made by the mould Penicillium which he named penicillin. The Australian pathologist, Howard Florey (1898-1968), furthered this research and developed penicillin's large-scale production during World War II. In 1943 scientists at the Squibb Laboratories in the US obtained pure penicillin in crystalline form. Fleming, Florey and Ernest Chain (1906-1979), a fellow member of the Oxford University research team, shared the 1945 Nobel Prize for Medicine for their contributions to the discovery and development of penicillin. The helmet and barbed wire show penicillin�s importance in World War II. (Photo by SSPL/Getty Images)