Photo 51

Photo 51 is the name given to an X-ray diffraction image of DNA taken by Rosalind Franklin in 1952 that was critical evidence in identifying the structure of DNA. The photo was taken by Franklin while working at King's College London in Sir John Randall's group.

The photo, shown to James D. Watson by Maurice Wilkins without Franklin's knowledge, was the critical evidence 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. 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.