how did alfred hershey and martha chase arrive at the conclusion that DNA is the genetic material ?

alfred hershey and martha chase worked with viruses that infact bacteria called bacteriophages. (bacteriophages attaches to the bacteria and its genetic material then enters the bacterial cell)

hershey and chase worked to discover whether it was protein or DNA from the viruses that entered the bacteria.

• They labelled some phages with radioactive sulphur and the others with radioactive phosphorus.

• These radioactive phages were used to infect E. coli.

• E.coli was then blended and centrifuged to remove viral particles.

• It was observed that bacteria with radioactive DNA were radioactive while those with radioactive proteins lost their radioactivity.

• This showed that it is the DNA that enters the bacteria from viruses and not proteins. Hence, it was concluded that DNA is the genetic material.