Question

How did Alfred Hershey and Martha Chase arrive at the conclusion that DNA is the genetic material?

Answer 1

Hershey and Chase performed an experiment which was conducted in 1952 by Alfred Hershey and Martha Chase that helped them to validate that DNA is a genetic material found in the animals.
While DNA had been known to biologists since 1869, many scientists still take it at the time that proteins carried the information for inheritance because DNA at that time appeared to be an inert molecule.

Complete answer: Hershey and Chase showed that when bacteriophages, which are composed of DNA and protein, infect bacteria and their DNA enters the host bacterial cell, but most of their protein does not.
Hershey and Chase and with the other scientists and some other subsequent discoveries all help them to prove that DNA is the hereditary material found in the animals.
Hershey and Chase used bacteriophage.
The phage enters the bacterium by attaching to it and they further inject its genetic material into it.
They put labels on the phage DNA with radioactive phosphorus-32.
They infect the E. coli by following the DNA phages.
So, in the end, Hershey and Chase come to the conclusion that DNA is genetic material, not protein.
They set on that a protective coat was formed around the bacteriophage, but the internal DNA is confirmed for its ability to produce new cells or progeny inside a bacterium.

Note: Hershey and Chase's experiment concluded that little sulfur-containing material entered the bacterial cell.
However, no particular decision was made related to the material that is sulfur-free and it enters the bacterial cell after phage adsorption.
Further research was necessary to conclude that it was solely bacteriophages' DNA that entered the cell and not a combination of protein and DNA where the protein did not contain any sulfur.