Frederick Griffith

Frederick Griffith (1877–1941) was a British bacteriologist whose focus was the epidemiology and pathology of bacterial pneumonia. In January 1928 he reported what is now known as Griffith's Experiment, the first widely accepted demonstrations of bacterial transformation, whereby a bacterium distinctly changes its form and function.

He showed that Streptococcus pneumoniae, implicated in many cases of lobar pneumonia, could transform from one strain into a different strain. The observation was attributed to an unidentified underlying principle, later known in the Avery laboratory as the "transforming principle" (abbreviated as T. P.) and identified as DNA. America's leading pneumococcal researcher, Oswald T. Avery, speculated that Griffith had failed to apply adequate controls. A cautious and thorough researcher, and a reticent individual, Griffith's tendency was to publish only findings that he believed truly significant, and Griffith's findings were rapidly confirmed by researchers in Avery's laboratory. His discovery was one of the first to show the central role of DNA in heredity.