Rosalind Franklin (1920 – 1958) was a chemist and X-ray crystallographer whose work on the structure of DNA was central to figuring out its double-helix shape. She was not included in the Nobel Prize in Physiology or Medicine for this discovery, which was awarded to Watson, Crick and Wilkins in 1962, because she had already died and the committee did not make awards posthumously.
Her work was also central to the understanding of the molecular structures of RNA, viruses, coal and graphite.