Maurice couldn’t believe it when I offered it to him. I took it down the corridor and gave it to him because it had reached the stage now when Rosalind was going to leave, so she suggested that I go down the corridor and give this beautiful structure B pattern, this photo 51, to Maurice. Wilkins thought that she was being brought in as an assistant, and eventually the relationship grew so fraught that Franklin stopped showing him her data, and she was planning on moving to Birkbeck College. Apparently, Franklin thought that she was being brought to King’s College London as an independent investigator who would be in charge of her own research. So, Rosalind Franklin was working with Maurice Wilkins but the two of them had a pretty bad working relationship. I only wish I’d been able to plug the value of looking at structure B as well as Structure A.Įlla Fitzgerald – I’ve Got the World on a String Now, Rosalind was absolutely determined that there was so much information in structure A’s diffraction pattern that was what she wanted to do and therefore put this photo 51 on one side and said we’ll come back to that.
What is puzzling, I think is still puzzling, is why they didn’t pursue that photograph once they had it. It’s very crisp, it’s very clean, it’s got this really neat ‘X’ shape, and apparently if you know something about crystallography, this photo just screams helix. At higher humidities, a different structure, structure B, appears.Īnd the best structure B pattern we ever got is photo 51, which I took and was called 51 because that was the 51 st photograph that we’d taken, Rosalind and I, in our efforts to sort out this A and B difference. The first corresponds to a crystalline form, structure A. Sodium thymonucleate fibres give two distinct types of X-ray diagram. One would produce the diffraction pattern so weak that you’d never see it, so I wound 35 fibres round a paperclip and then pushed the clip open a bit to make the fibres taught. You surround that, in the early days, with photographic film so that when the X-rays come in, they hit the atoms in the crystal and they’re diffracted out and they make spots on the photographic film.
Double helix full#
I mean it was a form of technology that was available from the 19 th century but it’s a tube full of gas that you run an electric current through and it emits X-rays, and then in order to study your molecule, the thing you’re interested in, you have to crystallise it. What you need is an X-ray source, which in those days would have been an X-ray tube. The only time I could get at the X-ray set in King’s, the only one that existed, was in the basement of the chemistry department, and that was below the level of the Thames and I was only allowed to play with it in the evenings. That wasn’t really discovered until the mid-40s and then, obviously, it became very important to study its structure. Everybody was interested in the structure of proteins back in the 30s because nobody thought that DNA could possibly be complicated enough to be the molecule of life. At the time, X-ray crystallography of large molecules – the sort of molecules that you get in living bodies – was still a very, very small field. Gosling, King’s College London, Molecular Configuration in Sodium Thymonucleate. The Franklin and Gosling paper was primarily about crystallographic work. I think a lot of people don’t necessarily know that there were three DNA papers instead of just the one, and I think the big reason that the Watson and Crick paper became the one that we do remember is because that’s the one where the structure of DNA was published, and I think as a consequence the second two papers have really fallen out a bit of consciousness.
I’m a historian of science at the American Academy of Arts and Sciences in Cambridge, Massachusetts. I’m Raymond Gosling, co-author of one of the papers in Nature, 1953, April, on the structure of DNA. So, it looked right and it was sheer elegance. Walking into the lab and seeing this double helix, of course, it looked familiar because all of the stator of the dimensions was the stuff that we got from our X-ray diffraction patterns. , Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid, J. , Microsomal particles of normal cow’s milk. Music: I’ve Got the World on a String by Ella Fitzgeraldįrom the Editorial and Publishing Offices of Nature, Macmillan and Co., St Martin’s Street, London. In this show, we’re going back to the 1950s.
Double helix archive#
This is the Nature PastCast, each month raiding Nature’s archive and looking at key moments in science. The Astonishing Hypothesis: The Scientific Search for the Soul (Simon & Schuster, 1994).
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