experiments in 1944 based off Griffith transformation experiments. still using R and S strains. mixed heat killed s- strain with live r- strain and transformation occurred. in a bunch of different tubes, they degraded different parts of the cell. in the control, no enzymes were used. Protein, DNA, and RNA were all present. When this tube is mixed with the heat- killed s- strain and R cells are added, transformation occurs. first experiment: used proteases (enzymes that degrade proteins). no more proteins are left on the heat- killed s- strain, but still had DNA and RNA. when you add r- cells, the s- cells are still present. transformation did occur. transformation still occurs if you take away the RNA. when the DNA is degraded and r- cells are added, there is no transformation. you get no s- cells. DNA is the only one required to make transformation occur; they proved that DNA is transforming material.