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| Blender Experiment by Hershey and Chase |
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| Hershey and Chase devised an experiment in the year 1952 with two different preparations of T2 phage. T2 phage contains both DNA and proteins. It is possible to examine which of the two components has the information to programme for the production of more viral particles. |
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| In one preparation the protein part was made radioactive with S35 and in the other the DNA was made radioactive with P32. |
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| These 2 phages were made to infect a culture of E. coli. Soon after infection, the E. coli cells were gently agitated in a blender to loosen the adhering particles (phage) and the culture was centrifuged. The heavier bacterial pellets settled at the bottom. The supernatant contained the lighter viral particles that had not entered the bacteria. |
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| It was found that when T2 phage containing radioactive protein was used as the infecting agent, the bacterial pellet contained very little radioactivity and most of the radioactivity was in the supernatant. |
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| But if T2 phage with radioactive DNA was used, the heavier bacterial pellets were radioactive. |
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| This experiment indicated that during infection with the virus, it is the DNA that actually entered the bacteria. |
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| This finding suggests that it is the viral DNA and not protein that contains information for the production of more viral particles and therefore, DNA must be the genetic material. |
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| Experiment of Hershey and Chase to show that DNA is the hereditary material in the bacteriophage T2 |
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