Hersey and Chase labeled the outer protein coat of a bacteriophage with radioactive sulfur, and the inner DNA with radioactive phosphorous. After allowing the bacteriophage to infect E.coli bacterium and undergoing a heavy blender process, the empty "ghost" phages were separated from the bacteria. The infected E.coli were positive for radioactive phosphorous, indicated that DNA was the genetic material inserted from the bacteriophage. The radioactive sulfur was not present in the infected bacteria, indicating that protein was not the genetic material.
