<P> Hershey and Chase concluded that DNA, not protein, was the genetic material . They determined that a protective protein coat was formed around the bacteriophage, but that the internal DNA is what conferred its ability to produce progeny inside a bacterium . They showed that, in growth, protein has no function, while DNA has some function . They determined this from the amount of radioactive material remaining outside of the cell . Only 20% of the P remained outside the cell, demonstrating that it was incorporated with DNA in the cell's genetic material . All of the S in the protein coats remained outside the cell, showing it was not incorporated into the cell, and that protein is not the genetic material . </P> <P> Hershey and Chase's experiment concluded that little sulfur containing material entered the bacterial cell . However no specific conclusions can be made regarding whether material that is sulfur - free enters the bacterial cell after phage adsorption . Further research was necessary to conclude that it was solely bacteriophages' DNA that entered the cell and not a combination of protein and DNA where the protein did not contain any sulfur . </P> <P> Hershey and Chase concluded that protein was not likely to be the hereditary genetic material . However, they did not make any conclusions regarding the specific function of DNA as hereditary material, and only said that it must have some undefined role . </P> <P> Confirmation and clarity came a year later in 1953, when James D. Watson and Francis Crick correctly hypothesized, in their journal article "Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid", the double helix structure of DNA, and suggested the copying mechanism by which DNA functions as hereditary material . Furthermore, Watson and Crick suggested that DNA, the genetic material, is responsible for the synthesis of the thousands of proteins found in cells . They had made this proposal based on the structural similarity that exists between the two macromolecules, that is, both protein and DNA are linear sequences of amino acids and nucleotides respectively . </P>

Why did hershey and chase use s and p why not radioactive c or n