Describe the experimental design that allowed Hershey and Chase to distinguish between the two options for genetic material?

Answer 1

Hershey and Chase knew that the particular phage they worked with has two basic components: DNA on the inside, coated with protein on the outside. In their expt theylabelled phages with radioisotopes . For one batch of infecting phages, they used a radioactive isotope of sulfur to label only the phages' protein coats.In another batch of phages, they used a radioactive isotope of phosphorus to label only DNA. Next, they allowed each batch of phages to infect separate cultures of nonradioactive bacterial cells. They then whirled each culture in a blender to shake loose any parts of the phages that remained outside the bacterial cells. Result of expt. confirmed that only DNA of phage entered bacteria .

Answer 2

Hershey and Chase used a bacteriophage virus with a protein coat labeled with radioactive sulfur and DNA labeled with radioactive phosphorus. By infecting bacteria with the labeled virus, they were able to track which component (protein or DNA) entered the bacterial cell and concluded that DNA, not protein, is the genetic material.