How did Hershey and Chase differentiate between DNA and protein in their experiment while proving that DNA is the genetic material?

Explanation

Hershey and chase purified biochemicals (proteins, DNA,RNA etc) from the heat killed .S. cells. They discovered the DNA alone from S bacteria caused R bacteria to become transformed. They also discovered that protein digesting enzymes and RNA digesting enzymes did not affect transformation. So the transforming principle was not a protein or RNA. Digestron with DNA se did inhibit transformation suggesting that the DNa caused the transformation.