Give an account of Hershey and Chase experiment. What did it conclusively prove?If both $DNA$ and proteins contained phosphorus and sulphur do you think the result would have been the same ?

The unequivocal proof that $DNA$ is the genetic material came from the experiments of Alfred Hershey and Martha Chase ($1952$). They worked with viruses that infect bacteria called bacteriophages. The bacteriophage attaches to the bacteria and its genetic material then enters the bacterial cell. The bacterial cell treats the viral genetic material as if it was its own and subsequently manufacture more virus particles.

Hershey and Chase worked to discover whether it was protein or $DNA$ from the viruses that entered the bacteria. They grew some viruses on a medium that contained radioactive phosphorus and some others on medium that contained radioactive sulfur. Viruses grown in the presence of radioactive phosphorus contained radioactive $DNA$ but not radioactive protein because $DNA$ contains phosphorus but protein does not

Similarly, viruses grown on radioactive sulfur contained radioactive protein but not radioactive $DNA$ because $DNA$ does not contain sulfur. Radioactive phageswere allowed to attach to

E. coli bacteria. Then, as the infection proceeded, the viral coats were removed from the bacteria by agitating them in a blender.

Radioactive phageswere allowed to attach to E. coli bacteria. Then, as the infection proceeded, the viral coats were removed from the bacteria by agitating them in a blender. The virus particles were separated from the bacteria by spinning them in a centrifuge. Bacteria which was infected with viruses that had radioactive $DNA$ were radioactive, indicating that $DNA$ was the material that passed from the virus to the bacteria.