John Howard Northrop was an American biochemist who, with James Batcheller Sumner and Wendell Meredith Stanley, won the 1946 Nobel Prize in Chemistry. The award was given for these scientists' isolation, crystallization, and study of enzymes, proteins, and viruses. Northrop was a Professor of Bacteriology and Medical Physics, Emeritus, at University of California, Berkeley.

James Batcheller Sumner was an American biochemist. He discovered that enzymes can be crystallized, for which he shared the Nobel Prize in Chemistry in 1946 with John Howard Northrop and Wendell Meredith Stanley. He was also the first to prove that enzymes are proteins.