These experiments were to make sure that DNA was the genetic material which had been discovered by the Swiss physician Friedrich Miescher in his experiments on white blood cells or leukocytes between 1868 and 1869. Hershey shared the 1969 Nobel Prize in Physiology or Medicine for his “discoveries concerning the genetic structure of viruses.”
They put labels on phage DNA with radioactive Phosphorus-32. They then followed the phages while they infected E. coli. They found that the radioactive element was only in the bacteria, and not in the phage.
In a second experiment, they put labels on the phage protein with radioactive Sulfur-35. After the phage was attached to the bacterium, the radioactive element was found in the phage, but not in the bacteria. This showed them that genetic material which infects the bacteria is DNA.
- Hershey A.D. and Chase M. (1952) Independent functions of viral protein and nucleic acid in growth of bacteriophage. J Gen Physiol. 36:39-56.