In Hershey and Chase experiment, supernatant has only protein coats of bacteriophage.

The Experiment conducted by Hershey and Chase:

In the experiment conducted by Hershey and Chase in 1952, they aimed to determine whether DNA or protein is the genetic material that is transmitted from bacteriophages (viruses that infect bacteria) to the bacterial host during infection. They used the T2 bacteriophage and the bacterium Escherichia coli (E. coli) as their model system for the experiment.

Experimental Setup:
1. The T2 bacteriophage consists of a protein coat (capsid) that encloses its genetic material, which could be either DNA or protein. It does not have a cell wall like E. coli.
2. The bacterium E. coli has a cell wall but no protein coat.

Experimental Procedure:
1. Hershey and Chase labeled the two components of the bacteriophage separately using radioactive isotopes. They labeled the DNA with radioactive phosphorus-32 (^32P) and the protein coat with radioactive sulfur-35 (^35S).
2. They infected two separate cultures of E. coli with the labeled bacteriophages.
3. After allowing the infection to occur, they used a blender to separate the phage particles from the bacterial cells.
4. The mixture was then centrifuged to obtain a pellet of bacterial cells and a supernatant containing the phage particles.

Results and Conclusion:
1. Hershey and Chase observed that when they analyzed the pellet of bacterial cells, it contained a significant amount of radioactive phosphorus (^32P), indicating that the DNA had been transferred from the phage to the bacterial cells during infection.
2. On the other hand, the supernatant did not contain any significant amount of radioactive phosphorus (^32P), indicating that the DNA was not present in the supernatant.
3. However, the supernatant did contain a significant amount of radioactive sulfur (^35S), indicating that the protein coats of the phages had been released into the supernatant during infection.
4. These results led Hershey and Chase to conclude that DNA, not protein, is the genetic material that is transmitted from bacteriophages to the bacterial host during infection.

Answer:
In the experiment conducted by Hershey and Chase, the supernatant contained the protein coats of the bacteriophage. This finding supported their conclusion that DNA, not protein, is the genetic material that is transmitted from bacteriophages to the bacterial host. Therefore, the correct answer is option 'C' - Protein coats of bacteriophage.