Biology & Genetics · 1944
Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types
Oswald T. Avery, Colin M. MacLeod, Maclyn McCarty
Overview
Avery, MacLeod and McCarty identified DNA — not protein — as the molecule that carries hereditary information. By purifying the 'transforming principle' that changes harmless pneumococci into virulent ones, they showed it was deoxyribonucleic acid.
Proved DNA is the genetic material, setting the stage for the double helix.
Key findings
Methods
Biochemical purification and enzymatic dissection: extracts from virulent bacteria were fractionated and treated with enzymes that selectively destroy proteins, RNA, or DNA, testing which treatment abolished the ability to transform a recipient strain.
Keywords
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