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P.A. Levene
He determined the basic structure of nucleotides that make up DNA. -
Fredrick Griffith
He studied two strains of a bacteria which causes pnuemonia. One strain had a sugar coat and the other didn't. The coated one is the one that causes pnuemonia and is smooth. The non-coated strain doesn't caused pnuemonia and is the rough. -
Oswald Avery
He and his colleges identified the molecule that transformed the R strain of bacteria into the S strain. Avery isolated different macromolecules, like DNA, protein, and lipids, from killed S cells, then exposed live R cells to the macromolecules seperately. Overall his conclusions were not widely accepted by the scentific community. Many other biologists question and experiment whether proteins or DNA were responsible for the transfer of genetic matieral. -
Erwin Chargaff
He analayzed the amount of adenine, guanine, thymine and cytosine in the DNA of various species. -
Rosalind Franklin
She indicated that DNA was a double helix, or twisted ladder shape, formed by two strands of nucleotides twisted around each other. -
Hershey and Chase
Alfred Hershey and Martha Chase published results of experiments that provided definitive evidence that DNA is a transforming factor. It concluded viral DNA was injected into the cell and provided the genetic information needed to produce new viruses. -
Watson and Crick
Using Franklin and Chargaff's data they measured the width of the helix and the spacing of the bases. They also built a molecule to their research. -
Maurice Wilkins
he was awarded a noble prize for his spectroscopic studies on nucleic acids which eventually led to the use of X-ray crystallography to define the Watson-Crick model of DNA. -
Linus Pauling
He proposed that DNA was a triple helix rather than a double helix.
