Early sample of Fleming’s mould, 1935/1936

Fleming's penicillin mould, 1935.
This sample marks penicillin's transition from an interesting phenomenon to a potential drug. In 1928 Alexander Fleming (1881-1955) discovered that a strain of Penicillium mould exuded a substance that killed certain bacteria. However neither the nature nor the significance of penicillin were clear to him. New antibacterial medicines such as Protonsil developed in the 1930s however did encourage his belief that it might be therapeutically important. Fleming reportedly gave this sample to a friend, complaining that penicillin was superior to Prontosil but nobody would listen. It was however work at Oxford University from 1940 which led to the isolation of penicillin and demonstration of its worth.
Currently on display in:
Making the Modern World
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