Hershey, Alfred Day

▪ 1998

      American biochemist (b. Dec. 4, 1908, Owosso, Mich.—d. May 22, 1997, Syosset, N.Y.), was recognized as one of the founders of molecular genetics and shared the 1969 Nobel Prize for Physiology or Medicine with Salvador Luria and Max Delbrück, two other giants in the field. The three were honoured for their enormous contributions to the understanding of genetic processes and of the fundamental role of nucleic acid in the transmission of inherited characteristics. Hershey carried out experiments primarily on bacteriophages or phages, viruses that infect bacteria. In the early 1940s Hershey, Luria, and Delbrück formed the core of the "phage group," an informal association of scientists from a variety of laboratories who collaborated in the study of bacteriophages. Hershey's research demonstrated the occurrence of such basic viral phenomena as the spontaneous mutation of genetic, heritable factors and the ability of genetic material from different viral particles to recombine—discoveries that helped other investigators devise methods to combat major disease-causing viruses. This work also led to a greater understanding of the molecular mechanisms by which all organisms, including humans, inherit genetic information. Hershey's best-known experiment was carried out in 1952 with his assistant Martha Chase at Cold Spring Harbor (N.Y.) Laboratory. Their work, often referred to as the "blender experiment" in deference to the common household appliance they employed, demonstrated that DNA alone, and not protein, is the stuff of which genes are made. That discovery, together with James Watson and Francis Crick's elucidation of the structure of DNA the next year, paved the way for scientists to study the molecular basis of inheritance. After earning (1934) a doctorate in chemistry from Michigan State College, Hershey taught at Washington University School of Medicine, St. Louis, Mo., where he remained until 1950. That year he joined the research staff of the department of genetics (later renamed the Genetics Research Unit) of the Carnegie Institution of Washington at Cold Spring Harbor. He was named director of the unit in 1962 and retired in 1974. In addition to the Nobel Prize, Hershey was awarded the Albert Lasker Award (1958) and the Kimber Genetics Award (1965). Hershey was also elected (1958) a member of the U.S. National Academy of Sciences.

* * *