On September 23, 1953, Rosalind Franklin presented a paper at a crystallography conference in Madrid summarizing her X-ray diffraction work on DNA. She had left King's College London the previous year for Birkbeck, taking her research on tobacco mosaic virus with her. The work she had done at King's — including Photograph 51, the diffraction image that Watson and Crick used without her knowledge to confirm the double helix structure — had been published in Nature the previous April alongside, but subordinate to, the Watson-Crick paper.

Franklin was born in 1920 in Notting Hill, London, into an affluent Jewish family. She studied chemistry at Cambridge and earned her doctorate from Cambridge in 1945. She spent three years in Paris learning X-ray crystallography, where she was treated as a full scientist among colleagues who respected her work. She took the King's College position in 1951.

At King's, the situation was different. Her colleague Maurice Wilkins, who had a different understanding of their working relationship than she did, showed Watson photograph 51 without asking her. Watson and Crick did not tell her they were using her data. Their February 1953 paper in Nature contained an acknowledgment of "the unpublished experimental results and ideas" of Franklin and Wilkins — buried in a footnote to a citation.

Franklin died of ovarian cancer in 1958 at thirty-seven. In 1962, Watson, Crick, and Wilkins received the Nobel Prize for the discovery of DNA's structure. The Nobel is not awarded posthumously.