Griffith's Experiment

Studied on streptococcus pneumonia which is bacteria capable of causing pneumonia in mouse ex. When SP is grown in medium it can grow in two different strains. 1st is R strain and S strain. 1. Injecting solution of living S cells of SP to mouse, developing pneumonia and killed the mouse. When blood was taken and grown on nutrient medium S cells could be seen injected previously 2. Injecting solution of living R strain cells of SP to mouse, didn't develop pneumonia and the mouse was alive. When blood was taken and grown on nutrient medium R cells could be seen injected previously 3. Injecting solution of heat killed S cells in which cells were completely dead and inactivated unable to cause illness, of SP to mouse, didn't develop pneumonia and the mouse was alive. When blood was taken and grown on nutrient medium nothing could be seen. 4. Injecting solution of living R cells + heat killed S cells of SP to mouse, develop pneumonia and the mouse was dead. When blood was taken and grown on nutrient medium mixture of living R cells and S cells.