The fact that only DNA of the Bacteriophages entered the host cell.
Explanation:
At the time of the experiment, scientists debated whether DNA or proteins were the genetic material. Many thought that DNA was simply used to store phosphorus because it was encased within the nucleus and was not a very active molecule. Hershey and Chase showed that when a bacteriophage virus infects a bacterial cell, only the DNA is injected into the cell while the protein case remains outside. This proved that DNA and not proteins was the genetic material.
