To prove that DNA has the genetic properties, Hershey and chase conducted experiments on T2 bacteriophages. A bacteriophage has simple molecular constitution as it consists of a capsid that is made up of protein, and DNA that is contained with in the head portion of the capsid. They incorporated radioactive isotopes of 32p into phage DNA and that of 35s intro proteins of a separated phase culture. Their experiments was based on the fact that DNA, but not the proteins contains phosphorus, and similarly sulphur is present in proteins not in DNA. These phase type were used independently to infect the e.coli. Hershey and chase showed that when 32p was used, all radioactivity was associated with bacterial cells and if followed, appeared in the progency phase. However, when 35s was used, all radioactive, material was limited to phase ghost. If we use the radio labelled C and N, the result will be different as both proteins and DNA will be radio lebelled.
