The story of insulin discovery

Many researchers had tried to isolate insulin from animal pancreas, but Frederick Banting, a young surgeon, and Charles Best, a medical student, were the ones that succeeded. They both worked hard in very difficult conditions in the late 1921 and early 1922 until final success. They encountered problems with the impurities of their extract that was causing inflammations, but J. Collip, their late biochemist collaborator, worked many hours and was soon able to prepare cleaner insulin, free from impurities. This extract was administered successfully to L. Thomson, a ketotic young diabetic patient, on 23 January 1922. Following this, Eli Lilly & Co of USA started the commercial production of insulin, soon followed by the Danish factories Nordisc and NOVO as well as the British Wellcome. Nicolae Paulescu who was professor of Physiology in Bucharest, was also quite close to the discovery of insulin but the researchers in Toronto were faster and more efficient. Banting and Macleod won the Nobel price, which Banting shared with Best and Macleod with J. Collip. The contribution of Paulescu in insulin discovery was recognized after his death.