It is frankly nonsense to say that "Rosalind Franklin demonstrated the existence of [DNA]." This is not to say that she didn't play a key role in our understanding of it, or that her role wasn't denied the recognition it deserved for many years.
Any implication that she was denied a Nobel prize on sexist grounds is also wide of the mark. Rosalind Franklin died of ovarian cancer in 1958 (aged just 37), and the Nobel Prize was awarded to her fellow scientists Francis Crick, James Watson and Maurice Wilkins in 1962. Nobel prizes can only be awarded to living persons.
In 1869, while working in Tübingen, Germany, the Swiss biochemist Friedrich Miescher discovered certain chemicals in the nuclei of white blood cells; these chemicals are now known as nucleic acids. Miescher succeeded in extracting a precipitate from the blood cells; he called it nuclein, but it's now known as DNA. He suggested that nuclein may be somehow involved in heredity, but the full significance of his discovery wasn't apparent until the final years of the 19th century, when the German biochemist Albrecht Kossel discovered the chemical composition of nucleic acids. Kossel isolated and described the five organic compounds that are present in nucleic acid (adenine, cytosine, guanine, thymine and uracil) which are key in the formation of DNA.
In the early 1950s, Rosalind Franklin was working as a research associate in the biophysics laboratory at King's College, London, where she used her expertise and X–ray diffraction techniques to analyse DNA fibres. She and her student Raymond Gosling 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 that Franklin herself had refined.
Maurice Wilkins was a colleague of Franklin's at King's College. The two did not get on; she was direct and intense, while he was shy and introverted. A key factor in the controversy over the importance of Franklin's role is that Wilkins showed Photograph 51 to Crick and Watson, who were carrying out similar research in the Cavendish Laboratory at Cambridge University, without her knowledge. Crick and Watson used characteristics and features of Photo 51 to develop the chemical model of the DNA molecule.
In his best–selling, highly-acclaimed book on the story of the discovery, The Double Helix (1968), Watson wrote: "Rosy, of course, did not directly give us her data. For that matter, no one at King's realized they were in our hands." He also wrote disparagingly of Franklin: "Clearly Rosy had to go or be put in her place ... Unfortunately Maurice could not see any decent way to give Rosy the boot" ... "Certainly a bad way to go out into the foulness of a ... November night was to be told by a woman to refrain from venturing an opinion about a subject for which you were not trained."
These remarks caught the attention of the emerging women's movement (this being the late 1960s), and Rosalind Franklin was portrayed as a wronged heroine. The myth was abetted by her tragically early death. (These are not my words; they come from an article by the journalist and biographer Brenda Maddox, published in the scientific journal Nature.)
Brenda Maddox also refutes allegations that Franklin was one of only two women scientists working at King's College, and that she was treated as a second–class citizen. She was not happy at King's, but this had more to do with her religion than her gender. (Franklin was Jewish, and King's – according to Maddox – was "a Church of England setting dominated by swirling cassocks and students studying for the priesthood.") She left in early 1953.
Since Franklin's death, Watson and Crick have admitted that they could not have discovered the double helix of DNA in the early months of 1953 without her work. And yet there is no evidence that Franklin felt bitter about Crick and Watson's achievement. Indeed, says Maddox, the three became close friends.
After leaving King's, Franklin worked at Birkbeck College – also in London. Here, in the years before her death, she bult a global reputation in the research of coals, carbons and viruses. She would never have imagined that she would be remembered as the unsung heroine of DNA. Nor could she have envisaged that King's College London, where she spent the unhappiest two years of her professional career, would dedicate a building – the Franklin–Wilkins building – in her honour and that of the colleague with whom she had been barely on speaking terms.
© Macclesfield Quiz League 2018