Rosalind Elsie Franklin (25 July 1920 – 16 April 1958) was a British biophysicist and X-ray crystallographer who made critical contributions to the understanding of the fine molecular structures of DNA, RNA, viruses, coal and graphite. The DNA work achieved the most fame because DNA (deoxyribonucleic acid) plays essential roles in cell metabolism and genetics, and the discovery of its structure helped scientists understand how genetic information is passed from parents to children.

Franklin is best known for her work on the X-ray diffraction images of DNA which led to discovery of DNA double helix. Her data, according to Francis Crick, were "the data we actually used" to formulate Crick and Watson's 1953 hypothesis regarding the structure of DNA. Furthermore, unpublished drafts of her papers (written just as she was arranging to leave King's College London) show that she had indeed determined the overall B-form of the DNA helix. However, her work was published third, in the series of three DNA Nature articles, led by the paper of Watson and Crick which only vaguely acknowledged her evidence in support of their hypothesis. After finishing her portion of the DNA work, Franklin led pioneering work on the tobacco mosaic and polio viruses. She died in 1958 at the age of 37 from complications arising from ovarian cancer.

Franklin was born in Notting Hill, London, into an affluent and influential British Jewish family. Her father was Ellis Arthur Franklin (1894 – 1964), a London merchant banker and her mother was Muriel Frances Waley (1894 – 1976); she was the elder daughter and second of the family of five children. Her father's uncle was Herbert Samuel (later Viscount Samuel) who was Home Secretary in 1916 and the first practising Jew to serve in the British Cabinet. He was also the first High Commissioner (effectively governor) for the British Mandate of Palestine. Her aunt Helen Carolin Franklin was married to Norman de Mattos Bentwich, who was Attorney General in the British Mandate of Palestine. She was active in trade union organisation and women's suffrage, and was later a member of the London County Council.

Franklin was educated at St Paul's Girls' School and North London Collegiate School where she excelled in science, Latin and sports. Her family was actively involved with a Working Men's College, where Ellis Franklin, her father, taught electricity, magnetism and the history of the Great War in the evenings and later became vice principal. Later Franklin's family helped settle Jewish refugees from Europe who had escaped the Nazis.

Franklin went up to Newnham College, Cambridge, in 1938 and studied chemistry within the Natural Sciences Tripos. One of the demonstrators who taught her was the spectroscopist W.C. Price. Later, he was one of her senior colleagues at King's College. In 1941 she was awarded Second Class Honours in her Finals. This was accepted as a bachelor's degree in the qualifications for employment. Cambridge started to award the titular B.A. and M.A. to women in 1947, and earlier women graduates received these retroactively.Franklin was awarded a research fellowship and, according to an entry on the web site of the  Dolan DNA Learning Center of the Cold Spring Harbor Laboratory, that is supported by the National Cancer Institute, "She spent a year in R.G.W. Norrish's lab without great success." Later, he received a Nobel Prize for his contributions to chemical kinetics.

Franklin continued to meet the requirements of the National Service Act by working as an Assistant Research Officer at the British Coal Utilisation Research Association (BCURA). The BCURA was located on the Coombe Springs Estate, near Kingston upon Thames on the South West outskirts of London. Professor Norrish was a wartime advisor to BCURA. John G. Bennett was the Director. Marcello Pirani and Victor Goldschmidt, both refugees from the Nazis, were consultants and lectured at BCURA while Franklin was there. She studied the porosity of coal. This work was the basis of her Ph.D. thesis The physical chemistry of solid organic colloids with special reference to coal for which Cambridge University awarded her a Ph.D. in 1945. It was also the basis of several papers. The French scientist Adrienne Weill was one of Franklin's tutors at Newnham. At the end of the war, according to Sayre, Franklin asked Weill to let her know of job openings for "a physical chemist who knows very little physical chemistry, but quite a lot about the holes in coal". At a conference in the Fall of 1946, Weill introduced Franklin to Marcel Mathieu, a director of the Centre National de la Recherche Scientifique (CNRS), the network of institutes that comprise the major part of the scientific research laboratories supported by the French government. This led to Franklin's appointment with Jacques Mering at the Laboratoire Central des Services Chimiques de l'Etat in Paris.

Mering was a crystallographer who applied X-ray diffraction to the study of rayon and other amorphous substances, in contrast to the thousands of regular crystals that had been studied by this method for many years. He taught her the practical aspects of applying X-ray crystallography to amorphous substances. This presented new challenges in the conduct of experiments and the interpretation of results. Franklin applied them to further problems related to coal, in particular the changes to the arrangement of atoms when it is converted to graphite. Franklin published several further papers on this work. It became part of the main stream of work on the physics and chemistry of coal, covered by a current monograph, the annual and other publications. Mering also continued the study of carbon in various forms, using X-ray diffraction and other methods.

In January 1951, 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. Although originally she was to have worked on x-ray diffraction of proteins and lipids in solution, Randall redirected her work to DNA fibers before she started working at King's since Franklin was to be the only experienced experimental diffraction researcher at King's in 1951. He made this reassignment, even before she started working at King's, because of the following pioneering work by Maurice Wilkins and Raymond Gosling - a PhD student assigned to help Franklin. Even using crude equipment, these two men had obtained an outstanding diffraction picture of DNA which sparked further interest in this molecule. Wilkins and Gosling had been carrying out x-ray diffraction analysis of DNA in the Unit since May 1950, but Randall had not informed them that he had asked Franklin to take over both the DNA diffraction work and guidance of Gosling's thesis. Randall's lack of communication about this reassignment significantly contributed to the well documented friction that developed between Wilkins and Franklin.

Franklin, working with her student Raymond Gosling, started to apply her expertise in x-ray diffraction techniques to the structure of DNA. She used a new fine focus x-ray tube and microcamera ordered by Wilkins, but which she refined, adjusted and focused carefully. Drawing upon her physical chemistry background, Franklin also skillfully manipulated the critical hydration of her specimens. When Wilkins inquired about this improved technique, Franklin replied in terms which offended Wilkins as Franklin had "an air of cool superiority". Franklin's habit of intensely looking people in the eye while being concise, impatient and directly confrontational to the point of abrasiveness unnerved many of her colleagues. In stark contrast, Wilkins was very shy, and slowly calculating in speech while he avoided looking anyone directly in the eye. In spite of the intense atmosphere, Franklin and Gosling 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 forms were termed DNA 'B' and 'A' respectively. Because of the intense personality conflict developing between Franklin and Wilkins, Randall divided the work on DNA. Franklin chose the data rich A form while Wilkins selected the 'B' form because his preliminary pictures had hinted it might be helical. He showed tremendous insight in this assessment of preliminary data. 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".

By the end of 1951 it was generally accepted at King's that the B form of DNA was a helix, but after she had recorded an asymmetrical image in 1952 May, Franklin became unconvinced that the A form of DNA was helical in structure. In July 1952, as a practical joke on Wilkins (who frequently expressed his view that DNA was helical), Franklin and Gosling produced a death notice regretting the 'death' of helical crystalline DNA (A-DNA). During 1952, Rosalind Franklin and Raymond Gosling worked at applying the Patterson function to the x-ray pictures of DNA they had produced. This was a long and labour intensive approach but would yield significant insight into the structure of the molecule.

By January 1953, Franklin had reconciled her conflicting data and had started to write a series of three draft manuscripts, two of which included a double helical DNA backbone. Her two A form manuscripts reached Acta Crystallographica in Copenhagen on 6 March 1953, one day before Crick and Watson had completed their model. Franklin must have mailed them while the Cambridge team was building their model, and certainly had written them before she knew of their work. On 8 July 1953 she modified one of these "in proof", Acta articles "in light of recent work" by the King's and Cambridge research teams. The third draft paper on the 'B' form of DNA, dated 17 March 1953, was discovered years later amongst her papers, by Franklin's Birkbeck colleague, Aaron Klug. He then published an evaluation of the draft's close correlation with the third of the original trio of 25 April 1953 Nature DNA articles. Klug designed this paper to complement the first article he had written defending Franklin's significant contribution to DNA structure. He had written this first article in response to the incomplete picture of Franklin's work depicted in Watson's 1968 memoir, The Double Helix.

As vividly described in The Double Helix, on 30 January 1953, Watson travelled to King's carrying a preprint of Linus Pauling's incorrect proposal for DNA structure. Since Wilkins was not in his office, Watson went to Franklin's lab with his urgent message that they should all collaborate before Pauling discovered his error. The unimpressed Franklin became angry when Watson suggested she did not know how to interpret her own data. Watson hastily retreated, backing into Wilkins who had been attracted by the commotion. Wilkins commiserated with his harried friend and then changed the course of DNA history with the following disclosure. Watson was shown (by Wilkins) Franklin's famous photograph 51, which had been given to Wilkins by Gosling. Watson, in turn, showed Wilkins a pre-publication manuscript by Pauling and Corey. Franklin and Gosling's photo 51 gave the Cambridge pair critical insights into the DNA structure, whereas Pauling and Corey's paper described a molecule remarkably like their first incorrect model.

In February 1953, Francis Crick and James D. Watson of the Cavendish Laboratory in Cambridge University had started to build a model of the B form of DNA using similar data to that available to both teams at King's. Much of their data were derived directly from research done at King's by Wilkins and Franklin. Franklin's research was completed by February 1953, ahead of her move to Birkbeck, and her data were critical. Model building had been applied successfully in the elucidation of the structure of the alpha helix by Linus Pauling in 1951, but Franklin was opposed to prematurely building theoretical models, until sufficient data were obtained properly to guide the model building. She took the view that building a model was to be undertaken only after enough of the structure was known. Ever cautious she wanted to eliminate misleading possibilities. Photographs of her Birkbeck work table show that she routinely used small molecular models, although certainly not ones on the grand scale successfully used at Cambridge for DNA. In the middle of February 1953, Crick's thesis advisor, Max Perutz gave Crick a copy of a report written for a Medical Research Council biophysics committee visit to King's in December 1952, containing many of Franklin's crystallographic calculations. Since Franklin had decided to transfer to Birkbeck College and Randall had insisted that all DNA work must stay at King's, Wilkins was given copies of Franklin's diffraction photographs by Gosling. By 28 February 1953 Watson and Crick felt they had solved the problem enough for Crick to proclaim (in the local pub) that they had "found the secret of life". However they knew they must complete their model before they could be certain.

Watson and Crick finished building their model on 7 March 1953, one day before they received a letter from Wilkins stating that Franklin was finally leaving and they could put "all hands to the pump". This was also one day after Franklin's two A form papers had reached Acta Crystallographica. Wilkins came to see the model the following week, according to Maddox on 12 March, and allegedly informed Gosling on his return to King's. It is uncertain how long it took for Gosling to inform Franklin at Birkbeck, but her original 17 March B form manuscript does not reflect any knowledge of the Cambridge model. Franklin did modify this draft later before publishing it as the third in the trio of 25 April 1953 Nature articles. On 18 March, in response to receiving a copy of their preliminary manuscript, Wilkins penned the following "I think you're a couple of old rogues, but you may well have something".

Crick and Watson then published their model in Nature on 25 April 1953 in an article describing the double helical structure of DNA with only a footnote acknowledging "having been stimulated by a general knowledge of" Franklin and Wilkin's 'unpublished' contribution. Actually, although it was the bare minimum, they had just enough specific knowledge of Franklin and Gosling's data upon which to base their model. As a result of a deal struck by the two laboratory directors, articles by Wilkins and Franklin, which included their x-ray diffraction data, were modified and then published second and third in the same issue of Nature, seemingly only in support of the Crick and Watson theoretical paper which proposed a model for the B form of DNA. Franklin left King's College London in March 1953 to move to Birkbeck College in a move that had been planned for some time.

Weeks later, on 10 April, Franklin wrote to Crick for permission to see their model. Franklin retained her scepticism for premature model building even after seeing the Crick – Watson model, and remained unimpressed. She is reported to have commented, "It's very pretty, but how are they going to prove it?" As an experimental scientist Franklin seems to have been interested in producing far greater evidence before publishing - as - proven a proposed model. As such her response to the Crick – Watson model was in keeping with her cautious approach to science. However, as documented above, she did not hesitate to publish preliminary ideas about DNA in Acta, even before they could be definitively proven. Most of the scientific community hesitated several years before accepting the double helix proposal. At first mainly geneticists embraced the model because of its obvious genetic implications. Broader acceptance for the DNA double helix did not start until about 1960, and was not openly acknowledged until 1961 during the 1962 Nobel prize nominations. It took Wilkins and his colleagues approximately seven years to collect enough data to prove and refine the proposed DNA structure. According to the 1961 Crick – Monod letter, this experimental proof, along with Wilkins having initiated the DNA diffraction work, were the reasons why Crick felt that Wilkins should be included in the DNA Nobel prize.

Franklin's work in Birkbeck involved the use of x-ray crystallography to study the structure of the tobacco mosaic virus (TMV) as a senior scientist with her own research group, funded by the Agricultural Research Council (ARC). She was recruited by physics department chair J.D. Bernal, a brilliant crystallographer who happened to be an Irish communist, known for promoting women crystallographers. In 1954 Franklin began a longstanding and successful collaboration with Aaron Klug. In 1955 Franklin had a paper published in the journal Nature, indicating that TMV virus particles were all of the same length, this was in direct contradiction to the ideas of the eminent virologist Norman Pirie, though her observation ultimately proved correct.

Franklin, and the research group she headed, focused on the structure of RNA, a molecule equally central to life as DNA. RNA actually constitutes the genome (central information molecule) of many viruses, including tobacco mosaic virus. She assigned the study of rod like viruses such as TMV (tobacco mosaic virus) to her PhD student Kenneth Holmes, while her colleague Aaron Klug worked on spherical viruses with his student John Finch, with Franklin coordinating and overseeing the work. Franklin also had a research assistant, James Watt, subsidised by the National Coal Board and was now the Leader of the "ARC group at Birkbeck. By the end of 1955 her team had completed a model of the TMV, to be exhibited at the upcoming Brussels World's fair. The Birkbeck team members were working on RNA viruses affecting several plants, including potato, turnip, tomato and pea.Franklin and Don Caspar produced a paper each in  Nature that taken together demonstrated that the DNA in TMV is wound along the inner surface of the hollow virus.

Her former colleagues at Birkbeck College, London Aaron Klug, John Finch and Kenneth Holmes moved to the Laboratory of Molecular Biology, Cambridge in 1962.

In the summer of 1956, while on a work-related trip to the United States, Franklin first began to suspect a health problem — she found she could no longer do up her skirt because of a lump around her abdomen. An operation in September of the same year revealed two tumours in her abdomen. After this period and other periods of hospitalization, Franklin spent time convalescing with various friends and family members. These included Anne Sayre, Francis Crick, his wife Odile, with whom Franklin had formed a strong friendship, and finally with the Roland and Nina Franklin family where Rosalind's nieces and nephews bolstered her spirits. Franklin chose not to stay with her parents because her mother's uncontrollable grief and crying upset her too much. Even while undergoing cancer treatment, Franklin continued to work, and her group continued to produce results, seven papers in 1956 and a further six in 1957. In 1957, the group was also working on the polio virus and had obtained funding from the Public Health Service of the National Institutes of Health in the United States for this. At the end of 1957, Franklin again fell ill and she was admitted to the Royal Marsden Hospital. She returned to work in January 1958 and she was given a promotion to Research Associate in Biophysics. She fell ill again on March 30 and died on April 16, 1958, in Chelsea, London, of bronchopneumonia, secondary carcinomatosis and carcinoma of the ovary. Exposure to X-ray radiation is sometimes considered a possible factor in her illness. Other members of her family have died of cancer, and the incidence of "female" cancer is known to be disproportionately high among Ashkenazi Jews. Her death certificate read: A Research Scientist, Spinster, Daughter of Ellis Arthur Franklin, a Banker.

Various controversies surrounding Rosalind Franklin came to light following her death.

Sayre states "In 1951 ... King's College as an institution, was not distinguished for the welcome that it offered to women ... Rosalind ... was unused to purdah ... there was one other woman scientist on the laboratory staff". Andrzej Stasiak states "Sayre's book became widely cited in feminist circles for exposing rampant sexism in science." Farooq Hussain states "there were seven women in the biophysics department ... Jean Hanson became an FRS, Dame Honor B. Fell, Director of Strangeways Laboratory, supervised the biologists". Maddox states, "Randall ... did have many women on his staff ... they found him ... sympathetic and helpful."

Sayre states "that while the male staff at King's lunched in a large, comfortable, rather clubby dining room" the female staff of all ranks "lunched in the student's hall or away from the premises". Elkin states that most of the MRC group typically ate lunch together (including Franklin) in the mixed dining room discussed below. And Maddox states, of Randall, "He liked to see his flock, men and women, come together for morning coffee, and at lunch in the joint dining room, where he ate with them nearly every day."

Claustrophobia has been cited as an unrecognised confound to some interpersonal issues attributed to sexism. Nevertheless, sexism is said to pervade the memoir of one peer, James Watson, in his book The Double Helix published 10 years after Franklin's death and after Watson had returned from Cambridge to Harvard. In this, he denigrates her work and frequently refers to her in patronizing terms as "Rosy", a name she never used. Much later, at Cambridge, Francis Crick acknowledges, "I'm afraid we always used to adopt -- let's say, a patronizing attitude towards her". And another Cambridge colleague, Peter Cavendish wrote in a letter, "Wilkins is supposed to be doing this work; Miss Franklin is evidently a fool".

Ironically, Franklin herself is said to have been "not immune to the sexism rampant in these circles; in a letter to her parents in January 1939, she called one lecturer 'very good, though female'".

One of Rosalind Franklin's important contributions to the Crick and Watson model was her lecture at the seminar in November 1951, where she presented to those present, among them Watson, the two forms of the molecule, type A and type B, and her position whereby the phosphate units are located in the external part of the molecule. She also specified the amount of water to be found in the molecule in accordance with other parts of it, data that have considerable importance in terms of the stability of the molecule. Franklin was the first to discover and formulate these facts, which in fact constituted the basis for all later attempts to build a model of the molecule. The other contribution included an X-ray photograph of B-DNA (called photograph 51), that was briefly shown to James Watson by Maurice Wilkins in January 1953, and a report written for an MRC biophysics committee visit to King's in December 1952 which was shown by Dr. Max Perutz at the Cavendish Laboratory to both Crick and Watson. This MRC report contained data from the King's group, including some of Rosalind Franklin's and Raymond Gosling's work, and was given to Francis Crick — who was working on his thesis on haemoglobin structure — by his thesis supervisor Max Perutz, a member of the visiting committee. Maurice Wilkins had been given photograph 51 by Rosalind Franklin's Ph.D. student Raymond Gosling, because she was leaving King's to work at Birkbeck. There was allegedly nothing untoward in this transfer of data to Wilkins, since the Director Sir John Randall had insisted that all DNA work belonged exclusively to King's and had instructed Franklin in a letter to even stop thinking about it. Also it was implied by Horace Freeland Judson, incorrectly, that Maurice Wilkins had taken the photograph out of Rosalind Franklin's drawer. However, the B-DNA X-ray pattern photograph in question was shown to Watson by Wilkins — without Franklin's permission.

Likewise Max Perutz saw "no harm" in showing an MRC report containing the conclusions of Franklin and Gosling's X-ray data analysis to Crick, since it had not been marked as confidential, although – in the customary British manner in which everything official is considered secret until it is deliberately made public – "The report was not expected to reach outside eyes". Indeed, after the publication of Watson's The Double Helix exposed Perutz's act, he received so many letters questioning his judgment that he felt the need to both answer them all and to post a general statement in Science excusing himself on the basis of being "inexperienced and casual in administrative matters".

Perutz also claimed that the MRC information was already made available to the Cambridge team when Watson had attended Franklin's seminar in November 1951. A preliminary version of much of the important material contained in the 1952 December MRC report had been presented by Franklin in a talk she had given in 1951 November, which Dr. Watson had attended but not understood. This seems to be a rather tenuous claim. There is a significant difference between the results Franklin achieved at the end of 1951 (at the time of the seminar) and those she held when editing the report – at the end of 1952. It was a year in which her knowledge substantially increased. This and more, Watson and Crick received the report from Perutz during February, 1953, a short time after Watson received Franklin’s type B photograph, no. 51. Thus, there is no doubt that the report helped them to analyze Franklin’s correct data, which explain this and other photographs.

The Perutz letter was as said one of three letters, published with letters by Wilkins and Watson, which discussed their various contributions. Watson clarified the importance of the data obtained from the MRC report as he had not recorded these data while attending Franklin's lecture in 1951. The upshot of all this was that when Crick and Watson started to build their model in February 1953 they were working with critical parameters that had been determined by Franklin in 1951, and which she and Gosling had significantly refined in 1952, as well as with published data and other very similar data to those available at King's. Rosalind Franklin was probably never aware that her work had been used during construction of the model, but Maurice Wilkins was.

Upon the completion of their model, Francis Crick and James Watson had invited Maurice Wilkins to be a co-author of their paper describing the structure. Wilkins turned down this offer, as he had taken no part in building the model. Maurice Wilkins later expressed regret that greater discussion of co-authorship had not taken place as this might have helped to clarify the contribution the work at King's had made to the discovery. There is no doubt that Franklin's experimental data were used by Crick and Watson to build their model of DNA in 1953. Some, including Maddox, have explained this citation omission by suggesting that it may be a question of circumstance, because it would have been very difficult to cite the unpublished work from the MRC report they had seen. Indeed a clear timely acknowledgment would have been awkward, given the unorthodox manner in which data were transferred from King's to Cambridge, however methods were available. Watson and Crick could have cited the MRC report as a personal communication or else cited the Acta articles in press, or most easily, the third Nature paper that they knew was in press. One of the most important accomplishments of Maddox's widely acclaimed biography is that Maddox made a well received case for inadequate acknowledgement. "Such acknowledgement as they gave her was very muted and always coupled with the name of Wilkins".

Twenty five years after the fact, the first clear recitation of Franklin's contribution appeared as it permeated Watson's account, The Double Helix, although it was buried under allegations that Franklin did not know how to interpret her own data and that she should have therefore shared her work with Wilkins, Watson, and Crick. This attitude is epitomized in the confrontation between Watson and Franklin over a pre-print of Pauling's mistaken DNA manuscript. Watson's words impelled Sayre to write her rebuttal, in which she designs her entire chapter nine, "Winner Take All" to be like a legal brief dissecting and analyzing the topic of acknowledgement. Unfortunately Sayre's early analysis was often ignored because of the supposed feminist overtones in her book. It should be noted that in their original paper, Watson and Crick do cite the X-ray diffraction work of both Wilkins and William Astbury. In addition, they admit their, "having been stimulated by a knowledge of the general nature of the unpublished experimental work of [groups led by both Wilkins and Franklin]". Franklin and Raymond Gosling's own publication in the same issue of Nature was the first publication of this more clarified X-ray image of DNA.

Franklin's part in the discovery of the nature of DNA was shown in the 1987 TV Movies Life Story, starring Tim Pigott - Smith as Francis Crick, Alan Howard as Maurice Wilkins, Jeff Goldblum as James Watson, and Juliet Stevenson as Rosalind. This movie portrayed Franklin in a somewhat stern role, but also alleged that Watson and Crick did use a lot of her work to do theirs.

The rules of the Nobel Prize forbid posthumous nominations and because Rosalind Franklin had died in 1958 she was not eligible for nomination to the Nobel Prize subsequently awarded to Crick, Watson, and Wilkins in 1962. The award was for their body of work on nucleic acids and not exclusively for the discovery of the structure of DNA. By the time of the award Wilkins had been working on the structure of DNA for more than 10 years, and had done much to confirm the Watson - Crick model. Crick had been working on the genetic code at Cambridge and Watson had worked on RNA for some years.