Maclyn McCarty (1911-2005) was an American geneticist. Maclyn McCarty devoted his life a to studying infectious disease organisms and is best known for his part in the monumental discovery that DNA, rather than protein, constitute the chemical nature of a gene. Uncovering the molecular secret of the gene in question - capsular polysaccharide of pneumococcal bacteria - led the way to studying heredity not only through genetics but also through chemistry, and initiated the dawn of the age of molecular biology. The research team of American geneticists Oswald Avery, Colin MacLeod, and Maclyn McCarty responsible for this feat (known as the Avery-MacLeod-McCarty experiment) is very important to the field of forensic science.