Alexander Fleming

1951: British bacteriologist and Nobel laureate Sir Alexander Fleming (1881 - 1955) working with a microscope in his laboratory. Fleming was born in Ayrshire and educated at St Mary's Hospital, Paddington, where he served as Professor of Bacteriology (1928 - 1948). Fleming was the first doctor to use anti-typhoid vaccine on a human patient and he also discovered the antiseptic properties of lysozyme found in tears, body fluids and certain plants. He is most famous for his discovery of the antibiotic powers of penicillin in 1928. Fleming shared the 1945 Nobel Prize for Physiology or Medicine with the two chemists who had perfected a method of producing penicillin. (Photo by Baron/Hulton Archive/Getty Images)