HE took 2 strains of bacteria:S strain (smooth) and R strain (rough).
He injected regular S strain into the mouse and the mouse got pnuemonia and died
He injected regular R strain into the mouse and it lived
Then he heated up the S strain and gave it to the mouse and the mouse lived.
- He heated the S strain Mixed it with the R strain
- He injected it into a rat
- The mouse died
- If the mouse would have only had the R strain it would have lived and not gotten pneumonia.
- The mouse died because the S strain caused Pneumonia.
- Griffith didn't know it back then, but what had changed the R cells into S was DNA.
- Scientists knew though that there was some type of disease causing ability that was transformed from 1 cell to another.