Maclyn McCarty (1911-2005), US geneticist. McCarty was born in Indiana, and studied at Stanford University. He is most famous for the part he played in the research known as the Avery-MacLeod-McCarty experiment in the early 1940s. This work demonstrated that DNA (deoxyribonucleic acid) was the transforming principle in the bacterial extracts that could cause benign bacterial strains to turn into the more virulent strains. Although McCarty and his fellow researchers did not receive a Nobel Prize, this is considered one of the fundamental discoveries in genetics. Photographed in the early 1940s.