Insulin
The extent of Aberdeen biochemist John Macleod’s involvement in the discovery of penicillin has been controversial.
He and Canadian doctor Frederick Banting received the 1923 Nobel prize in Physiology or Medicine for discovering and isolating the hormone at the University of Toronto following experiments with pancreas extracts in dogs and fish.
While Banting maintained Macleod’s role in the discovery was trivial, claiming the Scotsman had only lent him laboratory space, academic documents released posthumously restored Macleod’s role in insulin research.