Photo 51

Photo 51 is the nickname given to an X-ray diffraction image of DNA taken by Rosalind Franklin in 1952 [http://www.pbs.org/wgbh/nova/photo51/ Secret of Photo 51. Nova] ] that was critical evidence [http://www.pbs.org/wgbh/nova/photo51/anat-flash.html Nova] ] in identifying the structure of DNA.Watson JD, Crick FHC (1953). "A Structure for Deoxyribose Nucleic Acid". "Nature" 171: 737–738. [http://www.nature.com/nature/dna50/watsoncrick.pdf Full text PDF] ] The photo was taken by Franklin while working at King's College London in Sir John Randall's group.

James D. Watson was shown the photo by Maurice Wilkins, who had been given it with Franklin's apparent prior approval by Raymond Gosling. With the help of Francis Crick, he used it to win the Nobel Prize in Physiology or Medicine. It was the critical evidence ["The instant I saw the picture my mouth fell open and my pulse began to race." -- James D. Watson (1968), "The Double Helix", page 167. New York: Atheneum, Library of Congress card number 68-16217. Page 168 shows the X-shaped pattern of the B-form of DNA, clearly indicating crucial details of its helical structure to Watson and Crick.] that led to the confirmation of the postulated double helical structure of DNA, published during 1953 in a series of five articles in the journal "Nature".Double Helix: 50 Years of DNA. [http://www.nature.com/nature/dna50/archive.html Nature archives. Nature Publishing Group] ] Franklin and Raymond Gosling's own publication in the same issue of "Nature" was the first publication of this more clarified X-ray image of DNA.Franklin R, Gosling RG (1953) "Molecular Configuration in Sodium Thymonucleate". "Nature" 171"': 740–741. [http://www.nature.com/nature/dna50/franklingosling.pdf Full text PDF] ]

References