Rosalind Franklin

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Rosalind Franklin

Rosalind Elsie Franklin (July 25, 1920 - April 16, 1958) was a British physical chemist and crystallographer who made important contributions to the understanding of the fine structures of coal, DNA and viruses.

Contents

Background

Rosalind Franklin was born in London in the United Kingdom, into an affluent and influential Anglo-Jewish family. Her great uncle was Herbert Samuel (later Viscount Samuel) who was the first practising Jew to serve in the British Cabinet, as Home Secretary in 1916. He was also the first High Commissioner (effectively governor) for the British Mandate of Palestine. Her aunt Helen was married to Norman Bentwich who was Attorney General in the Palestine. Dr Franklin was educated at St Paul's Girls' School where she excelled in science and sport. Her family were actively involved in a local Working Men's College, where her father taught in the evenings. Later they helped settle Jewish refugees from Europe who had escaped the Nazis.

Cambridge and early career 1938-1950

In the autumn of 1938 Rosalind Franklin started at Newnham College, Cambridge. At this time women were not accepted as members of the University, simply as 'students of Girton and Newnham Colleges', the number of women students was kept to 500 (10% of the student body) and women were not entitled to a degree from the University. She passed her finals in 1941. Because of the ongoing war, World War II, she worked at the British Coal Utilization Research Association studying the fine structure of coal and charcoal and how to use them most efficiently, a problem affecting the war. Her work helped spark the idea of high-strength carbon fibres and was the basis of her doctoral degree in physical chemistry that she earned in 1945. After the war ended she went to Paris to work. She learned X-ray diffraction techniques during her three years at the Laboratoire central des services chimiques de l'╔┤at. She seemed to have been very happy there and earned an international reputation on the structure of carbons. Indeed on several occasions after accepting a position at King's, but before leaving Paris, she considered changing her mind and staying. Unfortunately, Jacques Mering, her mentor, had been unhappy about her decision to leave and refused to put his name on the papers she was writing, even though he had been equally involved in the work. It seemed she had little choice but to return to England.

King's College London 1951-1953

Rosalind Franklin started working as a research associate at King's College London in the Medical Research Council's (MRC) Biophysics Unit, directed by John Randall, at the beginning of January 1951. Originally to have worked on X-ray diffraction of proteins in solution, her work was redirected to DNA fibres. Maurice Wilkins was already carrying out X-diffraction analysis of DNA in the Unit (it was one of his photos, shown at a meeting in Naples in May 1951, which inspired James D. Watson to come to Cambridge to do similar research). Unfortunately, Randall had implied that Franklin alone would be working on DNA, apparently not informing Wilkins of that fact. Wilkins was on holiday when Franklin arrived, and so he returned to find that his research project had been taken over by a newcomer. This was not a good start to the relationship which went progressively downhill.

Discovery of the structure of DNA

Franklin together with her Ph.D. student Ray Gosling obtained some excellent X-ray diffraction photographs of DNA. They discovered that there were two forms of DNA, at high humidity (when wet) the DNA fibre became long and thin, when it was dried it became short and fat. These were termed DNA A (the dry or crystalline form) and DNA B (the wet or paracrystalline form). In October 1951 relations between Franklin and Wilkins were so bad that the work on DNA was divided, Franklin taking the A form to study and Wilkins the B form. Franklin had the better quality DNA and the better apparatus, but as would become apparent later, the B form was the form which produced the most easily interpretable X-ray diffraction pictures. The X-ray diffraction pictures taken by Franklin at this time have been called, by J. D. Bernal, 'amongst the most beautiful X-ray photographs of any substance ever taken.' In November 1951 King's held a colloquium on nucleic acid structure. Rosalind Franklin and Maurice Wilkins both gave presentations, James Watson was present. Shortly afterwards Francis Crick and Watson put together a model of DNA, but the flaws in the model were spotted immediately by Franklin. By the beginning of 1952 it was generally accepted in King's that the B form of DNA was a helix and Franklin's photograph 51 seemed to put the question beyond doubt. Because of the agreement not to work on the B form, Franklin never tried to interpret the photograph. In the Summer of 1952 Franklin told Randall that she was leaving King's to go to work at Birkbeck in January 1953. Gosling and Franklin were not convinced that DNA 'A' was a helical molecule. The disadvantage of working on the 'A' form of deoxyribonucleic acid is that it is a much more dense and tightly coiled molecule, which gives diffraction patterns which are more difficult to interpret. In December 1952 members of the department wrote up their work in a report for the MRC, in it Franklin gave important information about the space group the DNA crystal fell into, 'face-centred monoclinic'. In January 1953 Maurice Wilkins showed James Watson Franklin's photograph 51 (which he had every right to do, it was of the B form which had been assigned to him). Crick and Watson had already obtained much information from Wilkins about the dimensions of the molecule and so started to build a new model. Crick and Watson had also managed to get hold of a copy of the MRC report from the previous December. This contained the unpublished work by Franklin on the DNA crystal's space group, and therefore was not intended to be circulated to other laboratories. Crick and Watson realised this showed that the two chains were antiparallel. Watson and Crick succeeded in building a model of the B form of DNA incorporating the data, which was published in Nature on April 25, 1953 in an article describing the double-helical structure of DNA. Upon seeing the Crick and Watson model, Franklin is reported to have commented that it was very pretty 'but how are they going to prove it'. Crick and Watson never did prove their model. Articles by Wilkins and Franklin illuminating their X-ray diffraction data published in the same issue of Nature supported the Crick and Watson model for the B form of DNA. Francis Crick has commented that 'Strictly speaking, our model was not finally decisively proved until some 25 or so years later'. Rosalind Franklin never did work on the B form of DNA, and perhaps never knew that Crick and Watson had seen the MRC report. Franklin eventually left King's in March 1953 to move to Birkbeck.

Rosalind Franklin and DNA

Much has been written on the role that Franklin played in the discovery of the structure of DNA. Her work was an important basis for determining DNA's structure and used extensively by Crick and Watson. Franklin was very close to a solution, but had several obstacles to overcome. The antipathy between her and Maurice Wilkins was the major problem. It seems likely that they got off to a bad start with each other and their working relationship never recovered. This led to Franklin having no real collaborator (and so no one to trade ideas with), and to the two working in seclusion from each other, when they should have been working together. It has been implied by Wilkins himself that this situation may well have been deliberately exacerbated by John Randall. Watson has stated that Franklin should have discovered the structure of DNA as much as two years before he and Crick did (though Rosalind Franklin started to work on DNA in January 1951, two years and two months before the discovery, which means that according to Watson she should have discovered it in less than two months, and before her X-ray machine had even been built); on the other hand, Crick has said Franklin would have made the discovery within three months, if he and Watson had not published their paper. In fact, she had already prepared a draft paper describing the structure as a double helix when Crick and Watson produced theirs.

Franklin died of ovarian cancer in 1958 in London; which was quite possibly caused by exposure to radiation in the course of her research. She is interred in the Willesden Jewish Cemetery in London.

Wilkins, Watson, and Crick were awarded the Nobel Prize in Physiology or Medicine in 1962.

Recognition

Some have said that Franklin deserved a share of the 1962 Nobel Prize received by Crick, Watson and Wilkins, unfortunately her death in 1958 had made her ineligible. (Posthumous prizes are permitted only if the recipient dies after the award is announced).

King's College London opened the Franklin-Wilkins Building [1] (http://www.kcl.ac.uk/about/elevat/ch1.html) in 2000 in honour of Dr. Rosalind Franklin's and Dr. Maurice Wilkin's work at the college.

In 2004, Finch University of Health Sciences/The Chicago Medical School, located in North Chicago, IL, changed its name to Rosalind Franklin University of Medicine and Science.

Further reading

  • Maddox, Brenda Rosalind Franklin: The Dark Lady of DNA, 2002. ISBN 0060184078.
  • Sayre, Anne. 1975. Rosalind Franklin and DNA. New York: W.W. Norton and Company.
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