DNA was first isolated in 1869, by the Swiss physician Friedrich Miescher. In 1927, Nikolai Koltsov proposed that life passes along traits via a giant molecule composed of two mirror-image strands that replicate using each other as templates. In 1953, James Watson and Francis Crick proposed the now-accepted model of DNA's double-helix structure, for which they were awarded Nobel Prizes.Continue Reading
Many researchers were involved in the discovery of isolation, analysis and identification of DNA. In 1878, Albrecht Kossel isolated the non-protein part of nucleic acid, a major component of DNA. In 1919, Phoebus Levene identified additional parts of nucleic acid and correctly proposed that DNA consisted of a string of nucleotide units. In 1937, William Astbury produced x-rays which proved that DNA has a regular structure. Between 1928 and 1943, researchers including Frederick Griffith, Oswald Avery, Colin MacLeod, Maclyn McCarty, Alfred Hershey and Martha Chase performed work establishing that inherited traits were passed along by DNA.
In 1952, Rosalind Franklin and Raymond Gosling made an x-ray diffraction image of DNA. Watson and Crick derived their proposition about DNA's double-helical structure partly on this image. Maurice Wilkins performed similar work and was awarded a Nobel Prize for using x-ray analyses of DNA to confirm its double-helical structure. However, only Watson, Crick and Wilkins received Nobel Prizes because at the time that Nobel Prizes were awarded to them, Nobel Prizes were not awarded posthumously, and debate about who should receive credit for the discovery of DNA continues in modern times.Learn more about Molecular Biology & DNA