filters
in 1953
Their genetic material
Their genetic material
The Hershey-Chase experiment was a scientific study conducted in 1952 by Alfred Hershey and Martha Chase. They used bacteriophages, viruses that infect bacteria, to demonstrate that DNA, not protein, is the genetic material that carries hereditary information. The key finding of the experiment was that when the bacteriophages infected bacteria, only the DNA of the virus was injected into the bacterial cell, not the protein coat. This provided strong evidence that DNA is the molecule responsible for transmitting genetic information.
The genetic mateial is made of DNA and not of proteins
The genetic mateial is made of DNA and not of proteins
They might have concluded that both protein and DNA transmitted hereditary material. The 32P was a radioisotope in DNA, and the 35S was a radioisotope in proteins. They were used to track the DNA and proteins to see if they were injected by a virus into a bacterium.
that DNA rather than the protein coat of a virus contains the hereditary material.
Hershey and Chase knew that the particular phage they worked with has two basic components: DNA on the inside, coated with protein on the outside. In their expt theylabelled phages with radioisotopes . For one batch of infecting phages, they used a radioactive isotope of sulfur to label only the phages' protein coats.In another batch of phages, they used a radioactive isotope of phosphorus to label only DNA. Next, they allowed each batch of phages to infect separate cultures of nonradioactive bacterial cells. They then whirled each culture in a blender to shake loose any parts of the phages that remained outside the bacterial cells. Result of expt. confirmed that only DNA of phage entered bacteria .
They found that all of the viral DNA and little of the protein had entered E. coli cells. Then they concluded that DNA is the hereditary molecule in viruses.
virus
DNA