True or false: Hershey-Chase labeled the phage DNA with radioactive 32P?

True or false: Hershey-Chase labeled the phage DNA with radioactive 32P?

• A. Not indicated
• B. False
• C. Both true and false
• D. True

Answer: (D)

Labeling DNA with 32P works because DNA contains phosphate groups, so using radioactive phosphorus tracks the fate of the genetic material. In the Hershey-Chase experiment, phage DNA was labeled with 32P and the phage protein coat with 35S. After infection and separation, the radioactivity inside the bacterial cells came from 32P, not 35S, showing that DNA entered the cells and carried genetic information. This is why labeling the phage DNA with radioactive 32P is true.

Labeling DNA with 32P works because DNA contains phosphate groups, so using radioactive phosphorus tracks the fate of the genetic material. In the Hershey-Chase experiment, phage DNA was labeled with 32P and the phage protein coat with 35S. After infection and separation, the radioactivity inside the bacterial cells came from 32P, not 35S, showing that DNA entered the cells and carried genetic information. This is why labeling the phage DNA with radioactive 32P is true.