The Nobel Prize in Chemistry 1946 was divided, one half awarded to James Batcheller Sumner "for his discovery that enzymes can be crystallized",the other half jointly to John Howard Northrop and Wendell Meredith Stanley "for their preparation of enzymes and virus proteins in a pure form".
 

Doctor James Sumner's discovery of the possibility of crystallizing an enzyme was the first convincing proof that enzymes are proteins. It thus became possible, for the first time, to attack the problem of the chemical nature of these substances, so important in chemistry, biology and medicine. As is often the case with pioneer work, his results were not immediately accepted everywhere, but today they form a foundation for and have pointed the way to some of the most important work in biochemistry. Doctor John Northrop and his collaborators have developed the crystallization of enzymes and other active proteins into an art, The conditions for successful work in this field were explored by him, and in the course of that work interesting relationships between enzymes and related proteins were discovered, which may ultimately afford a clue to a fuller understanding of the mode of action of these substances.
 

Doctor Wendell Stanley, the demonstration of the fact that a virus can be crystallized in the same way as many proteins and enzymes, and that it actually is a protein, at once opened up an almost unlimited field of research with fascinating possibilities. He has not only thrown open the portals to this domain, but successfully exploring its possibilities, and rich fruits have already been harvested.