Maclyn McCarty is a distinguished bacteriologist who has done important work on the biology of streptococci and the origins of rheumatic fever, but he is best known for his involvement in early experiments which established the function of DNA. In collaboration with Oswald Avery and Colin Munro Mac Leod, McCarty identified DNA as the substance which controls heredity in living cells. The three men published an article describing their experiment in 1944, and their work opened the way for further studies in bacteriological physiology, the most important of which was the demonstration of the chemical structure of DNA by James Watson and Francis Crick in 1953.

McCarty was born in South Bend, Indiana. His father worked for the Studebaker Corporation and the family moved often, with McCarty attending five schools in three different cities by the time he reached the sixth grade. In his autobiographical book, The Transforming Principle, McCarty...