In January 1951, Franklin began working as a research associate at the King's College London in the biophysics unit, where director John Randall used her expertise and X-ray diffraction techniques (mostly of proteins and lipids in solution) on DNA fibers. Studying DNA structure with X-ray diffraction, Franklin and her student Raymond Gosling made an amazing discovery: They took pictures of DNA and discovered that there were two forms of it, a dry "A" form and a wet "B" form. One of their X-ray diffraction pictures of the "B" form of DNA, known as Photograph 51, became famous as critical evidence in identifying the structure of DNA. The photo was acquired through 100 hours of X-ray exposure from a machine Franklin herself had refined.
John Desmond Bernal, one of the United Kingdom’s most well-known and controversial scientists and a pioneer in X-ray crystallography, spoke highly of Franklin around the time of her death in 1958. "As a scientist Miss Franklin was distinguished by extreme clarity and perfection in everything she undertook," he said. "Her photographs were among the most beautiful X-ray photographs of any substance ever taken. Their excellence was the fruit of extreme care in preparation and mounting of the specimens as well as in the taking of the photographs."
Despite her cautious and diligent work ethic, Franklin had a personality conflict with colleague Maurice Wilkins, one that would end up costing her greatly. In January 1953, Wilkins changed the course of DNA history by disclosing without Franklin's permission or knowledge her Photo 51 to competing scientist James Watson, who was working on his own DNA model with Francis Crick at Cambridge.
Upon seeing the photograph, Watson said, "My jaw fell open and my pulse began to race," according to author Brenda Maddox, who in 2002 wrote a book about Franklin titled Rosalind Franklin: The Dark Lady of DNA.
The two scientists did in fact use what they saw in Photo 51 as the basis for their famous model of DNA, which they published on March 7, 1953, and for which they received a Nobel Prize in 1962. Crick and Watson were also able to take most of the credit for the finding: When publishing their model in Nature magazine in April 1953, they included a footnote acknowledging that they were "stimulated by a general knowledge" of Franklin's and Wilkins' unpublished contribution, when in fact, much of their work was rooted in Franklin's photo and findings. Randall and the Cambridge laboratory director came to an agreement, and both Wilkins' and Franklin's articles were published second and third in the same issue of Nature. Still, it appeared that their articles were merely supporting Crick and Watson's.
