What was the goal of the Hershey-Chase experiment?

-

A series of experiments conducted in 1952 by Alfred Hershey and

Martha Chase confirming that DNA was the genetic material in

cells

-

The experiment was conducted using T2 phage; a virus that infects

bacteria. They do so by attaching to the surface of a bacterium and

injecting its genetic material into the bacteria. The structure had

recently been elucidated by electron microscopy.

-

The 1st experiment- Phage DNA was labeled with radioactive 32P.

Phosphorous is an important component of DNA which is not found in

Amino Acids; protein building blocks.

-

The phages were allowed to infect E.coli bacteria and through a

series of elegant experiments they were able to observe transfer of

labeled phage DNA into the cytoplasm of the bacteria.

-

In the second experiment, they labeled phages with radioactive

Sulfur 35 which is found in amino acids cysteine and Methionine.

After infection of E.coli, they sheared off the phage protein

shells from the infected cells using high speed blender and

centrifugation to separate.

-

After centrifugation, the radioactive sulfur was found in the

protein portion confirming the hypothesis that the genetic

information transferred was DNA and not protein