This page discusses the 1952 experiment by A. D. Hershey and Martha Chase, which used the T2 DNA virus to demonstrate that genes are composed of DNA. By labeling DNA with radioactive phosphorus and pr...This page discusses the 1952 experiment by A. D. Hershey and Martha Chase, which used the T2 DNA virus to demonstrate that genes are composed of DNA. By labeling DNA with radioactive phosphorus and proteins with radioactive sulfur, they showed that only the DNA entered E. coli cells, while the protein coat remained outside. This confirmed that genetic information is carried by DNA, as it directed the production of new virus particles.