Rosalind Franklin arrived at King’s College, London, in 1951. The expert x-ray crystallographer had been told she would be the only one in her department working on the structure of DNA, so she did not know that Maurice Wilkins was already doing the same thing just down the hall. No one had told Wilkins about Franklin’s assignment; he assumed she was a technician hired to do his x-ray crystallography work. And so, a clash began. Wilkins thought Franklin displayed an appalling lack of deference that technicians of the era usually accorded researchers. To Franklin, Wilkins seemed prickly and oddly over-interested in her work.
Wilkins and Franklin had been given identical samples of DNA. Franklin’s meticulous work with hers yielded the first clear x-ray diffraction image of DNA as it occurs in cells, and she gave a presentation about it in 1952. DNA, she said, had two chains twisted into a double helix, with a backbone of phosphate groups on the outside, and bases arranged in an unknown way on the inside. She had calculated the DNA’s diameter, the distance between its chains and between its bases, the angle of the helix, and the number of bases in each coil. Crick, with his crystallography background, would have recognized the significance of the work—if he had been there. Watson was in the audience, but he was not a crystallographer, and he did not understand the implications of Franklin’s data.
Franklin started to write a research paper on her findings. Meanwhile, and perhaps without her knowledge, Wilkins reviewed Franklin’s x-ray diffraction image with Watson, and Watson and Crick read a report detailing Franklin’s unpublished data. Crick, who had more experience with molecular modelling than Franklin, immediately understood what the image and the data meant. Watson and Crick used that information to build their model of DNA. On April 25, 1953, Franklin’s paper appeared last in a series of articles about the structure of DNA in the journal Nature. It supported with solid experimental evidence Watson and Crick’s theoretical model, which appeared in the first article of the series.
Rosalind Franklin died in 1958, at the age of 37, of ovarian cancer probably caused by extensive exposure to x-rays during her work. At the time, the link between x-rays, mutations, and cancer was not understood. Because the Nobel Prize is not given posthumously, Franklin did not share in the 1962 honour that went to Watson, Crick, and Wilkins for the discovery of the structure of DNA.
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