DNA Timeline

By katelyn301

  • Friedrich Miescher

    discovered the nucleic acids

  • Phoebus Levene

    discovered the components of DNA and defined the term “nucleotides”

  • Frederick Griffith

    started experimenting on finding the hereditary materials of DNA

  • Oswald Avery/Colin Macleod/Maclyn McCarty

    improved on Griffith’s experiments to show DNA was the hereditary materials (not proteins) in bacterial (and possibly other organisms as well)

  • Erwin Chargaff

    examined the abundance of the base pairs and determined that base pairs have a 1:1 ratio with their designated pair

  • Alfred Hershey/Martha Chase

    conducted experiments using viruses to confirm that DNA was the hereditary material of organisms not protein

  • James Watson/Francis Crick

    wrote papers on the structure of DNA, describing the double helix sugar and phosphate backbone with the bases facing outwards. This proposal was rejected as it made no chemical sense

  • Linus Pauling/Robert Corey

    proposed a triple helix structure with the bases on the outside of the DNA backbone. This theory was also rejected.

  • Rosalind Franklin/Maurice Wilkins

    Franklin took an x-ray diffraction of the DNA structure. This is known as photo 51. Using many mathematical algorithms she worked out that the “x” she saw in the image was the double helix.