Alfred Day Hershey (1908-1997) worked for the Carnegie Institution of Washington Department of Genetics from 1950-1962, and then was director of the CIW Genetics Research Department until his retirement in 1974.
He was one of the founding members of the famous Phage group and explored the molecular basis of biology through phage research. Hershey is best known for his 1952 work with Laboratory Assistant Martha Chase, and their famous "Waring Blendor" experiment in which it was proved definitively that DNA, not protein, is the hereditary biological material.
He won the Nobel Prize in Physiology or Medicine, along with Max Delbrück and Salvador Luria in 1969, for "for their discoveries concerning the replication mechanism and the genetic structure of viruses". [Nobelprize.org]