After allowing phages grown with bacteria in a medium that contained 32p and 35s, hershey and chase used a centrifuge to separate the phage ghosts from the infected cell. they then examined the infected cells and found that they contained which demonstrated that is the phage's genetic material.

By examining the infected cells it was found that they contained DNA, which demonstrated that the DNA molecule is the phage's genetic material. Since the phage DNA entered the infected cell, it would be logical that the DNA is the genetic material. A molecules does not have to be labeled for it to be genetic material.