In the Hershey-Chase experiment, which molecule was labeled with 32P to track genetic material?

In the Hershey-Chase experiment, which molecule was labeled with 32P to track genetic material?

• A. Protein
• B. Lipids
• C. DNA
• D. RNA

Answer: (C)

The key idea is that DNA contains phosphate groups, while the protein part of a phage coat does not. In the Hershey–Chase experiment, researchers labeled the phage DNA with a radioactive isotope of phosphorus (32P) and the protein coat with radioactive sulfur (35S). After allowing infection and separating the outside coats from the infected cells, only the material inside the bacterial cells carried the 32P label. That shows the information needed to make new viruses was carried by DNA, not by the protein coat. In this setup, DNA is the molecule tracked with 32P, which is why the correct answer is DNA.

The key idea is that DNA contains phosphate groups, while the protein part of a phage coat does not. In the Hershey–Chase experiment, researchers labeled the phage DNA with a radioactive isotope of phosphorus (32P) and the protein coat with radioactive sulfur (35S). After allowing infection and separating the outside coats from the infected cells, only the material inside the bacterial cells carried the 32P label. That shows the information needed to make new viruses was carried by DNA, not by the protein coat. In this setup, DNA is the molecule tracked with 32P, which is why the correct answer is DNA.