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Hershey-Chase Experiment

In 1952, Hershey and chase infected bacteria with T2 phages that had been radioactively labeled either in their DNA component (with 32P) or in their protein component (with 32S).The infected bacteria were agitated in a blender, and two fractions were separated by centrifugation. One contained the empty phage coats that were released from the surface of the bacteria; these consist of protein and therefore carried the 32S radioactive label. The other fraction consisted of the infected bacteria themselves. Most of the 32P label was present in the infected bacteria. The progeny phage particles produced by the infection contained 30% of the original 32P label. The progeny received very little less than 1% of the protein contained in the original phage population.

 

This experiment therefore showed directly that the DNA of parent phages enters the bacteria and than becomes part of the progeny phages, exactly the pattern of inheritance expected of genetic material.
 



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