The structure of deoxyribonucleic acid (DNA) was discovered in 1953 by two molecular biologists, James Dewey Watson (1928 to 2025) and Francis Harry Compton Crick (1916 to 2004). Watson and Crick were awarded the Nobel Prize in Physiology or Medicine in 1962 for their pioneering work. This is the accepted version of history.
However, Rosalind Franklin (1920 to 1958), an English chemist whose expertise in X-ray crystallography made a significant contribution, may have paved the way for Watson and Crick. Yet Franklin has never been given due recognition for her painstaking work in producing DNA images and data that Watson and Crick used to build their model of DNA's structure.
Rosalind Franklin's story involves intellectual property theft, sexism, and deceit, and the struggle of a woman scientist to be accepted in the male-dominated scientific community of the 1950s. Recent scholarship suggests Franklin should be credited as an equal co-discoverer of DNA's structure. Whether Franklin should be acknowledged as one of the discoverers largely rests on the question: how should 'scientific discovery' be defined?
Deoxyribonucleic acid, or DNA, is a set of genetic instructions inside cells that is unique to every individual and determines how we look and how our bodies function. DNA passes along hereditary traits from generation to generation.
DNA was known to scientists before the 1950s. In 1869, the Swiss physician, Johann Friedrich Miescher (1844 to 1895), was the first to identify the molecule now known as DNA. He called it 'nuclein' and developed techniques for extracting it from cells. Austrian biologist and mathematician Gregor Mendel (1822 to 1884) also proposed a theory of inheritance based on the transmission of genes from parents to offspring, accounting for similar familial traits such as eye colour.
What was not known was the twisting, ladder-like shape of DNA and how DNA stores information and copies itself. Unlocking DNA's secrets would help scientists understand genetic susceptibility to specific disorders and contribute to drug development and gene therapy.
By the early 1950s, several research groups were working on revealing the structure. James Watson, born on the South Side of Chicago, Illinois, and Northampton-born Francis Crick, were both researchers at the Cavendish Laboratory at Cambridge University, England. They were in a race against the American chemist Linus Pauling (1901 to 1994) of the California Institute of Technology, who published an article in early 1953 that erroneously proposed a triple-stranded DNA structure.
Rosalind Franklin, along with her PhD student and research assistant, Raymond Gosling (1926 to 2015), and New Zealand-born biophysicist Maurice Wilkins (1916 to 2004), worked at John T. Randall laboratory at King's College in London. Wilkins, who became friends with James Watson, would later betray his work colleague as scientists sought to be the first to uncover the structure of DNA.
Rosalind (pronounced 'Ros-lind') Elsie Franklin, one of five children, was born in London on 25 July 1920, to Muriel and Ellis Franklin. Her father, Ellis, was a successful banker, and Rosalind was sent to private schools. She dreamed of being a scientist, finding children's toys of little interest.
In 1931, Rosalind attended St. Paul's Girls' School before studying French in Paris, returning to England in 1938 and entering Newnham, a women's college at the University of Cambridge. At Newnham, she was attracted to the work of Professor William Bragg (1862 to 1942), the 'father of X-ray crystallography' – a method of shining X-rays onto DNA cells that have been converted into crystals. The X-rays diffract (bend or spread out) as they pass through the crystals, and the scatter pattern produces a 3D image of the atoms in the crystal on a photographic plate, allowing scientists to determine the exact shape.
Rosalind Franklin became exceptionally skilled at X-ray crystallography and was awarded a doctorate in chemistry in 1945. In 1951, she was offered a fellowship at King's College to work as a crystallographer alongside Maurice Wilkins. Franklin was hired when Wilkins was absent from the laboratory, and this led to an openly hostile relationship between them. Wilkins was said to have treated Franklin as his assistant, referring to her as 'Rosy', when she had, in fact, been recruited to lead X-ray crystallography research. In response, Franklin refused to share her findings.
It was also a challenging time for a woman scientist in the 1950s, particularly given that women were excluded from eating lunch in the male-only common rooms. This led to Franklin working in isolation.
Meanwhile, in 1951, at the Cavendish Laboratory, Watson and Crick believed they had solved the puzzle of DNA's structure. They proposed a model consisting of three strands twisting around each other in a spiral (called a triple helix). Rosalind Franklin and Maurice Wilkins travelled from London to see the model after Watson had attended a lecture given by Franklin on her DNA work.
Unfortunately, it was a humiliating experience for Watson and Crick. Their model incorrectly showed the sugar-phosphate 'backbones,' which every DNA strand has, in the centre of the helix instead of on the outside. Watson, whose doctoral training was in ornithology, had not understood parts of Franklin's lecture and was said to have resented a woman lecturing. Rosalind Franklin returned to London after informing the duo that their model was flawed. Watson and Crick were told to leave the study of DNA structure to King's College researchers, which only further fuelled Watson's antipathy towards Franklin.
Back at King's, Franklin found that the DNA molecule's interaction with water changed its form and 'twistiness.' DNA exists in two forms when water content is controlled – A and B, with the B form being more hydrated or 'wet.' This distinction became important when Franklin and Gosling took a series of photographs of a thin DNA fibre in May 1952 with a specially designed microcamera. The fibre was bombarded with X-rays for 62 hours.
Photograph 51, taken by Gosling under Franklin's supervision, is often referred to as the most important scientific photograph ever taken. It is an image of the more hydrated B form. No scientist had taken a photograph of the wet form before this moment. The pattern of dark spots on the photographic plate was a distinct central 'X,' indicating a helical (spiral) structure with the sugar-phosphate 'backbones' on the outside. More astonishing was the photographic view – down the core of the DNA molecule – and the clarity of the photograph for that time period.
Franklin's analysis of the B-DNA data was published in Nature, April 1953. Watson and Crick also published a paper in the same issue, and their analysis was based on Franklin's Photograph 51 findings. Yet, Rosalind Franklin's contribution has largely been cast aside.
Months earlier, on January 30, 1953, James Watson visited King's. Franklin had placed Photograph 51 in a drawer, and without her knowledge or permission, Maurice Wilkins showed the photograph to Watson, whose reaction was immortalised in his 1968 bestselling book, The Double Helix: "The instant I saw the picture my mouth fell open and my pulse began to race" (quoted in Gibbons, 66).
Watson understood what he was looking at – DNA's double helix structure.
At this point, a number of questions arise:
- Did Rosalind Franklin realise she had revealed DNA's structure? Why did she seemingly discard Photograph 51?
- Would James Watson and Francis Crick have discovered DNA's structure without Photograph 51 and Franklin's data?
- Was Rosalind Franklin the victim of institutional sexism and unethical behaviour?
Recent scholarship (Cobb & Comfort, 2023) suggests that Franklin, a gifted scientist, described both forms of DNA in her 1951 lecture notes as a 'big helix with several chains.' Unlike Watson and Crick, though, she was not a model-builder, preferring to treat Photograph 51 as merely one piece of evidence among diffraction patterns as opposed to a single 'eureka' moment. Hers was a mathematical approach, but had Franklin assembled a full 3D model, history may have recorded her as the discoverer of DNA's structure.
The A or less hydrated form of DNA also interested Franklin far more because the fibres were 'drier' and more ordered and would therefore result in richer, cleaner diffraction patterns from which she could extract valuable data. Franklin, who was Jewish, was also unhappy in the Church of England setting at King's College and ultimately moved to Birkbeck College, London, where she led a team studying the molecular structure of the tobacco mosaic virus. These two factors are most likely the reason Rosalind Franklin did not fully capitalise on her DNA work at King's.
What constitutes 'scientific discovery' is perhaps the key question. Aside from Photograph 51 being shown to James Watson, Crick's academic supervisor, molecular biologist Max Perutz (1914 to 2002), also shared Franklin's unpublished results with Crick, which Perutz received in December 1952. Max Perutz did not consult the King's research group. This has led critics to suggest that Watson and Crick came into possession, via unethical means, of Franklin's work, and that without it, they may not have made their breakthrough discovery and been awarded the Nobel Prize. In The Double Helix, James 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" (Watson, 62).
Watson's reaction to Photograph 51 has been portrayed as an 'a-ha' moment of lone genius insight or internal cognitive thinking that sparked a brilliant idea. Because Franklin was unaware of how her research was used or that her colleague, Maurice Wilkins, had, in effect, betrayed her, she became a feminist icon with accusations that she was a victim of chauvinism and not duly credited for her pioneering work.
Yet, this ignores her active role in the discovery process and the argument that a 'scientific breakthrough' is usually a team effort, or that an 'external, visible discovery' like Photograph 51 should not be regarded as a discovery in its own right. Additionally, Franklin presented her data in her 1951 public lecture, which was attended by James Watson. Since it was not confidential information, Watson and Crick were at liberty to interpret the data and apply it to their model building. The issue is proper acknowledgement of Franklin's work and whether she should have been recognised as a co-discoverer of DNA structure. Conversely, it could be said that without Watson and Crick's interpretation of her data, there would be no discussion of Franklin as a co-discoverer.
British science journalist Nicolas Wade has suggested that Franklin's portrayal as a wronged heroine is a myth and that she became close friends with Francis Crick, who said in a 2003 interview: "Our belief is that she didn't realize until the structure came out how important DNA was. For her, it was just another problem" (Wade, 2022).
Franklin never claimed that she had been denied credit for her experimental work.
Rosalind Franklin's life was dramatically cut short. She died in April 1958 at the age of 37, most likely due to radiation exposure from her work with X-rays. Following treatment, she stayed at the home of Francis Crick and his wife, Odile, lending support to Wade's assertion that Franklin and Crick had a close relationship rather than an antagonistic one.
Twelve years after her death, Maurice Wilkins had the grace to admit his wrongdoing in showing Photograph 51 to James Watson, saying:
It was all here . They were working at Cambridge along certain lines, and we were working along certain lines . It was a question of time. They could not have gone on to their model, their correct model, without the data developed here. They had that – I blame myself, I was naïve – and they moved ahead.
(Rapoport, 123)
Rosalind Franklin did not live long enough to see Watson and Crick share the Nobel Prize in 1962 with Maurice Wilkins, who was recognised for his early X-ray diffraction studies on DNA. The Nobel Prize is not awarded posthumously, so Rosalind Franklin could not have been included, and it has never gone to more than three people for one award.
If scientific discovery is viewed as a collaborative process that may extend over months or years, then Rosalind Franklin should rightly be recognised as the equal fourth co-discoverer. James Watson, who was only 25 when he and Crick published the double-helix structure of DNA in 1953, led a long but somewhat controversial life, dying in November 2025 at the age of 97.
Watson stated in a footnote to an article in Nature, April 1953, that he and Crick had been "stimulated by a knowledge of the general nature of the unpublished experimental results and ideas of Dr M H F Wilkins, Dr R E Franklin and their co-workers at King's College" (737). The wording was careful. It did not explicitly state the extent to which Watson and Crick relied on Franklin's work, and he never publicly credited her. Whatever he may have thought of Franklin as a scientist was overshadowed by his dismissive and questionable view of Franklin in The Double Helix, which he wrote when he was 40 years old:
Though her features were strong, she was not unattractive and might have been quite stunning had she taken even a mild interest in clothes. This she did not. There was never lipstick to contrast with her straight black hair, while at the age of thirty-one her dresses showed all the imagination of English bluestocking adolescents... Unfortunately… there was no denying she had a good brain.
(Watson, 17 to 18).
Passages like this might explain why Watson never fully acknowledged Rosalind Franklin's crucial role in the discovery of DNA.
Watson's legacy has been tarnished by later public statements. In 2019, Cold Spring Harbor Laboratory in Long Island, New York, where Watson became the lab's second director in 1968, stripped him of all titles and honors following controversial remarks about race and intelligence. In 2012, at a conference in Dublin, Watson said, when asked about women in science: "I think having all these women around makes it more fun for the men but they're probably less effective" (Nuwer).
James Watson was the first Nobel Laureate to sell his prize, raising USD 4.1 million, mainly because he had become a pariah in the scientific community, and speaking engagements had dried up.
Between 1953 and her death in 1958, Rosalind Franklin demonstrated she was a world-class crystallographer. At Birkbeck College, her work on the tobacco mosaic virus, the polio virus, and the role of ribonucleic acid (RNA) in viruses established the field of structural virology, which investigates the key components of viruses to understand how they function, leading to the design of effective vaccines.
British biophysicist and chemist Aaron Klug (1926 to 2018), who worked with Franklin at Birkbeck, was awarded the Nobel Prize in Chemistry in 1982 for developing crystallographic electron microscopy, a technique that helps reveal the 3D structure of molecules. Klug credited Rosalind Franklin's meticulous research approach, saying that she showed him that "... you have to tackle long and difficult problems rather than publishing clever papers" (Advice for Young Scientists).
Klug's remark is a fitting tribute to a brilliant scientist, who should be regarded as the co-discoverer of DNA's structure – arguably one of the most important scientific discoveries, reshaping biology and medicine.