Oswald Avery and the identification of DNA as the genetic material

In February 1944, when the whole world was consumed by the ravages of a World War, an important paper appeared in the rather obscure Journal of Experimental Medicine, entitled “Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types: Induction of Transformation by a Deoxyribonucleic Acid Fraction Isolated from Pneumococcus Type III”. The principal author of the paper was a short, soft-spoken physician of Canadian origin, Oswald Theodore Avery. The carefully reasoned paper of Avery and his colleagues at the Rockefeller Institute in New York, Colin MacLeod and Maclyn McCarty, was the culmination of meticulous work carried out for over a decade, following the startling results on pneumococcal transformation reported by the British physician Frederick Griffith in 1928. Though the paper was initially met with scepticism from the scientific community, it went on to pave the way for ushering in the new field of molecular genetics. It was also the inspiration for a young American graduate student by the name of James Watson, to team up with the British biophysicist Francis Crick, to solve the structure of DNA. This article attempts to highlight the triumphs and disappointments in the pursuit of the identification of the “transforming principle”.