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Phoebus Levene
In 1905, Phoebus Levene was appointed as head of the biochemical labratory at the Rockefeller Institute of Medical Research. Here, he identified the components of DNA. He also showed that the components were linked together in the order phosphate-sugar-base to form units. He called each of these units a nucleotide. http://en.wikipedia.org/wiki/Phoebus_Levene -
Frederick Griffith
Griffith discovers pneumococcal transformation, which showed that Streptococcus pneumoniae, implicated in many cases of lobar pneumonia, could transform from one strain into a different strain. His discovery was one of the first to show the central role of DNA in heredity. http://en.wikipedia.org/wiki/Frederick_Griffith -
Oswald Avery
Oswald Avery discovers that DNA is the material of which genes and chromosomes are made. http://en.wikipedia.org/wiki/Oswald_Avery -
Linus Pauling
In the early 1950s, Linus Pauling propsed his first DNA model, based more on common sense than mathematical reasoning. http://elvis.engr.wisc.edu/uer/uer96/author9/index.html -
Watson and Crick
At the same time as Linus Pauling, Watson and Crick were studying to find the structure of hemoglobin http://elvis.engr.wisc.edu/uer/uer96/author9/index.html -
Maurice Wilkins & Rosalind Franklin
At King's College in London, Maurice Wilkins was studying the DNA molecule. He needed an x-ray specialist to aid him in his search. He called in Rosalind Franklin because she could make excellent x-rays, despite using poor equipment. http://elvis.engr.wisc.edu/uer/uer96/author9/index.html http://elvis.engr.wisc.edu/uer/uer96/author9/index.html -
Watson & Crick Obtain Important Information
Watson attended a lecture that Rosalind Franklin was giving to her co-workers on her work thus far with DNA. Watson based his model on a value that he rememered from the lecture. The value turned out to be wrong. They were told to abandon their research. However, Franklin argued with Wilkins and eventually shut him out of her work. Wilkins a friend of Watson and Crick, gave them important information about Franklin's research. -
Hershey & Chase
Alfred Hershey & Martha Chase helped confirm that DNA was genetic material. At the time, some scientists thought that protein carried genetic information. Hershey and Chase's experiment showed that when bacteriophages, which are composed of DNA and protein, infect bacteria, their DNA enters the host bacterial cell, but most of their protein does not. http://en.wikipedia.org/wiki/Hershey%E2%80%93Chase_experiment -
Erwin Chargaff
Erwin Chargaff discovered two rules that helped lead to the discovery of the double helix structure of DNA.. He shared his research with Watson & Crick, which helped them deduce the double helix shape of DNA. http://en.wikipedia.org/wiki/Erwin_Chargaff -
Watson & Crick Complete Their Model of DNA
Using Franklin's data, Watson & Crick complete their model of the DNA molecule. http://elvis.engr.wisc.edu/uer/uer96/author9/index.html