Ask A Scientist© Biology Archive

Question:  I would like to know the characteristics of Griffth's experiment, 
and Hershey-Chase experiment.
pei01

Answer:  For the H-C experiment:  It was designed to show that the type of virus 
known as a bacteriophage infected bacteria by injecting its DNA, and not by 
incorporating the entire virus into the bacterium.  This was important because 
it showed that the entire replication of the virus could be coded for in the DNA 
of the virus, and not in the coat protein.  They labeled with radioactivity the 
coat of the virus using one type of label 35-S, and the DNA with another, 32-P 
and then infected bacteria.  After infection, the bacteria contained only 32-P, 
and no 35-S. The viruses went on to destroy the bacteria and reproduce, and the
new viruses contained no 35-S in their coats. 
Source: Biology, 3rd ed., by Solomon et al., although the same
information is in almost all texts at the college level. --ProfBill