In their side by side experiments Hershy and Chase incorporated ³⁵S into

Hashey and Chase worked with T2 bacteriophase. They grew some viruses on a medium that contained radioactive phosphorus (³²P) and some others on medium that contained radioactive Sulphur (³⁵S) viruses grown in the presence of ³²P contained radioactive DNA contains phosphorus but protein does not. Viruses grown ³⁵S contained radioactive protein but not radioactive DNA because DNA does not contain Sulphur.