Florey and Chain Develop Penicillin for Clinical Use

At Oxford University, Howard Florey and Ernst Boris Chain transformed Alexander Fleming's 1928 laboratory observation into a viable antibiotic. Norman Heatley developed the back-extraction purification method that enabled bulk production. On May 25, 1940, mouse trials demonstrated penicillin's effectiveness against streptococcal infection. The team treated their first patient, policeman Albert Alexander, on February 12, 1941, producing dramatic initial improvement before supplies ran out. Florey and Heatley traveled to the United States, securing American industrial partnership for mass production.