Griffith, Frederick

Fig. 180 Griffith, Frederick . Griffith's results.

Griffith, Frederick

English medical bacteriologist who, in 1928, published a paper showing that it was possible to convert one type of Streptococcus pneumoniae bacterium into a new type. More specifically Griffith worked with two strains of bacterium: type r type s rough outer coat, smooth outer coat, nonvirulent in mice virulent in mice His results are summarized in Fig. 180. Griffith proposed that in experiment 4 the heat-killed ‘S’ type somehow converted the living ‘R’ type to virulent ‘S’ types, in a process he called TRANSFORMATION. Later it was shown that the transforming ‘principle’ was DNA.