Born in Yonkers, New York, Northrop received his B.S. from Columbia University in 1912, his M.A. in 1913, and Ph.D. in 1915. His desire to achieve academically is not surprising since he came from a long lineage of illustrious academics, including Princeton University President Jonathan Edwards (1703-1758) and philanthropist Frederick C. Havemeyer, who gave a chemical laboratory to Columbia University. His father, John Northrop, who was killed in a laboratory accident, was a member of the zoology department of Columbia University. His mother, Alice Belle Rich Northrop, taught botany at Hunter College.

Northrop himself is best known for his studies of enzymes and his contribution to virus research. Northrop continued the work of James B. Sumner, who had isolated and crystallized a bean protein called urease in 1926. While many researchers dismissed Sumner's work as insignificant, Northrop drew upon it to conduct his own research.

In 1930 Northrop crystallized pepsin...