[7] Koshland wrote in an autobiographical article that he decided to become a scientist in the eighth grade after reading two popular books about science, Microbe Hunters by Paul de Kruif and Arrowsmith by Sinclair Lewis.

[8] Attending Phillips Exeter Academy[9] for high school Koshland then became the third generation of his family to matriculate to the University of California, Berkeley, where he majored in chemistry.

The next five years, 1941–46, were spent working with Glenn T. Seaborg at the University of Chicago on the top-secret Manhattan project, where his team purified the plutonium that was used to make the atomic bomb at Los Alamos.

[12] In the same period he studied the effect of using chemical modification to change the serine residue in the active site of subtilisin to cysteine,[13] (in parallel with a similar experiment done independently and almost simultaneously.

A little later Koshland and colleagues introduced the principal alternative to the model of Monod, Wyman and Changeux[15] to explain protein cooperativity.

[17] His laboratory made three major discoveries concerning protein phosphorylation in bacteria: He spearheaded the reorganization of the biological sciences at Berkeley, merging eleven departments into three.

[7] After his wife's death in 1997 he reconnected with onetime Berkeley classmate Yvonne Cyr San Jule and they were married in Lafayette on August 17, 2000.