Question

How did Alfred Hershey and Martha Chase arrive at the conclusion that DNA is the genetic material?

Answer 1

Hershey and Chase used T2 phage, a bacteriophage. The phage infects a bacterium by attaching to it and injecting its genetic material into it. They put labels on phage DNA with radioactive Phosphorus-32. They then followed the phages while they infected E. coli. Hershey and Chase concluded that DNA, not protein, was the genetic material. They determined that a protective protein coat was formed around the bacteriophage, but that the internal DNA is what conferred its ability to produce progeny inside a bacterium.