Sin título

Griffith's Experiment

In 1928, Frederick Griffith conducted one of the first experiments to show that cells possessed genetic material

Griffith's experiment involved the use of two strains of pneumococcus – a deadly virulent strain (S) or a non-virulent strain (R)

When Griffith infected mice with the non-virulent bacteria (strain R), the mice survived.

When Griffith infected mice with the virulent bacteria (strain S), the mice died.

When Griffith infected mice with heat-killed virulent bacteria (strain R), the mice survived as the bacteria had been killed.

When Griffith infected mice with a mix of heat-killed strain S and living strain R, the mice were found to have died

From this Griffith’s concluded that the living R cells had somehow been transformed into virulent S cells

This indicated that there was some form of transferrable genetic material present within the cells (i.e. DNA)

Other conclusion: a chemical substance from one cell is genetically transforming another cell