Final answer:
Hershey and Chase were able to determine that DNA was the genetic material by using radioactive labeling and observing the presence of phosphorus in DNA.
Step-by-step explanation:
Experiments conducted by Martha Chase and Alfred Hershey in 1952 provided confirmatory evidence that DNA was the genetic material and not proteins. Chase and Hershey were studying a bacteriophage, which is a virus that infects bacteria. They labeled one batch of phage with radioactive sulfur, ³5S, to label the protein coat, and another batch with radioactive phosphorus, 32p, to label the DNA. Because phosphorus is found in DNA, but not protein, the DNA was tagged with radioactive phosphorus. This allowed Hershey and Chase to determine that DNA, not protein, was the genetic material.