Question

Did Hershey and Chase's experiment demonstrate that DNA was a double helix?

Answer 1

Hershey and Chase experiment:

1. Two scientists, Alfred Hershey and Martha Chase worked on bacteriophages to prove that DNA is the genetic material.
2. Scientists grow viruses in a radioactive phosphorus medium and a radioactive sulfur medium.
3. After doing so, they observed that viruses grown in radioactive phosphorus contained radioactive DNA.
4. There was no presence of radioactive protein.
5. Viruses that were grown in radioactive sulfur contained radioactive protein.
6. There was no radioactive DNA.
7. Then these radioactive bacteriophages were attached to E.coli bacteria.
8. By blending them, the viral coats were removed.
9. Then by centrifuging, the virus particles were separated.
10. Then they observed that the bacteria which was virus-infected and had radioactive DNA was radioactive and the other one with radioactive protein was not radioactive, which clearly meant that DNA is the genetic material that passed from the virus to the bacteria as protein does not pass from virus to bacteria.
11. This experiment was basically divided into three sections: Infection, Blending, and Centrifugation.
12. Hershey and Chase’s experiment proved that DNA is the genetic material and not protein.
13. So, Hershey and Chase's experiment did not prove that DNA is a double helix.
14. DNA as a double helix was proved by Watson and Crick in 1953.