The Hershey–Chase experiment showed that DNA entered bacteria and carried the genetic instructions of bacteriophages.
Alfred Hershey and Martha Chase studied viruses called bacteriophages, which infect bacteria. A phage consists mainly of DNA enclosed in a protein coat. The researchers separately labeled phage DNA with radioactive phosphorus-32 and phage protein with radioactive sulfur-35.
After the phages infected bacterial cells, blending separated the empty viral coats from the bacteria. Most of the phosphorus label was found with the bacterial cells, while most of the sulfur label remained with the discarded coats. This indicated that DNA, not protein, entered the cells and directed production of new phages.
The 1952 result strongly supported DNA as genetic material, following earlier evidence from experiments by Frederick Griffith and by Oswald Avery, Colin MacLeod, and Maclyn McCarty. It helped prepare the way for the molecular biology revolution.