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Rosalind Franklin

Who Was Rosalind Franklin?

Rosalind Franklin was a scientist whose work was instrumental in one of the greatest discoveries of modern science: the structure of DNA. However, Rosalind Franklin's work with DNA and her contribution to the discovery of the double helix were largely overlooked in her lifetime. James Watson and Francis Crick, together with Franklin's colleague Maurice Wilkins, received the Nobel Prize for their discovery of the structure of DNA in 1962. Rosalind Franklin was not included in the award, as a Nobel Prize can only be shared by three living scientists.

How Did Rosalind Franklin Contribute to the Discovery of DNA Structure?

Watson and Crick were not alone in their quest to discover the structure of DNA. The Cambridge University-based duo was in a race against the renowned scientist Linus Pauling and his colleagues at the California Institute of Technology. While Watson and Crick did not collaborate with Rosalind Franklin directly, her expertise and X-ray diffraction images of crystallized DNA were critical in helping them solve the mystery of the structure of DNA.

Watson and Crick's quest to discover DNA's structure began with their very first meeting in the summer of 1951. Their first attempt at solving the structure of DNA that fall was a failure. The DNA structure they proposed consisted of three strands of DNA arranged in a helix, with the phosphates in the center.

Reportedly they shared their model with their Cambridge colleagues Maurice and Rosalind Franklin, and Franklin was highly critical. Any positive ions in the helix's core, she pointed out, would be surrounded by water. They would thus be neutral and therefore unable to hold the phosphates together.

Since DNA soaks up a significant amount of water, the phosphate groups would most likely be on the outside of the DNA molecule, not on the inside as Watson and Crick's three-stranded helix model showed.

Unimpressed with their model, Sir William Lawrence Bragg, the director of Cavendish Laboratory where Watson and Crick worked, put the pair to work on other projects. Crick went back to his work on proteins, and Watson was assigned to the crystallographic study of the tobacco mosaic virus. Though they were officially taken off the search for the structure of DNA, Watson and Crick continued to discuss the problem.

In February of 1953 Linus Pauling, together with his colleague Robert B. Corey, appeared to have won the race, with the publication of their paper, 'A Proposed Structure for the Nucleic Acids.' Watson and Crick were crushed—until they realized that Pauling's recently published three-stranded model had many of the same flaws as their discarded model and therefore could not be correct.

When Pauling's mistake became obvious, Bragg seized the opportunity to put Watson and Crick back to work full-time on the question of the structure of DNA. Although Watson and Crick were enthusiastic, they were essentially stumped.

A big breakthrough came when, without Rosalind Franklin's knowledge, Watson and Crick gained access to her research—a report written for the Medical Research Council on the structure of DNA, obtained by Crick via his thesis advisor Max Perutz.

Watson and Crick also got access to Franklin's X-ray diffraction images of crystallized DNA. The most notable was perhaps the image known as 'Photo 51', which Franklin's graduate student Raymond Gosling handed over to Maurice Wilkins.

The combination of Rosalind Franklin's images, which seemed to confirm the helical structure of DNA, and her crystallographic calculations proved critical to helping Watson and Crick solve the mystery of DNA's structure. Watson and Crick published their findings on the double helix in a paper titled 'A Structure for Deoxyribose Nucleic Acid' in April of 1953.

What Did Rosalind Franklin Do Next?

In March 1953 Rosalind Franklin left King's College for Birkbeck College, to lead their X-ray diffraction studies on plant viruses, with a particular focus on the tobacco mosaic virus (TMV). Watson and Crick published their paper outlining the double helix model the following month, in April 1953.

Though Franklin's work proved key to helping Watson and Crick devise their model, their paper included a mere footnote acknowledging that they were 'stimulated by a knowledge of the general nature' of the unpublished work and ideas of Dr. M.H.F. Wilkins and Dr. R.E. Franklin and their King's College colleagues.

During her five years at Birkbeck College, Franklin published 17 papers on viruses. Her team's pioneering work on the molecular structures of viruses laid the groundwork for structural virology.

In the final years of her career, Franklin received an increasing number of invitations to speak at conferences around the world. In 1954 and 1956, she made trips to the United States, where she collaborated with other researchers and established contacts around the country. While in the US she was invited by the Royal Institution to create five-foot models of helical and spherical viruses for the 1958 Brussels World's Fair.

Unfortunately Franklin never lived to see her models exhibited in Brussels, as her bright career was cut short by cancer. During her 1956 trip to America, she experienced the first symptoms of what would be diagnosed that fall as ovarian cancer.

Franklin continued to work at an impressive pace through multiple surgeries and remissions. She also successfully applied for a three-year research grant from the United States Public Health Service of the National Institutes of Health. It was the largest fund ever received at Birkbeck, and she decided to use the funds to decipher the polio virus' crystal structure.

Sadly, Rosalind Franklin was unable to see the fruits of her work with the polio virus, as she succumbed to cancer on April 16, 1958. She was 37 years old.

After Franklin's death, a Birkbeck College researcher by the name of Aaron Klug took over her research group. Together with another researcher, John Finch, he continued Franklin's work on the polio crystal structure. Their paper, published in 1959, was dedicated to her memory. Aaron Klug was awarded a Nobel Prize in Chemistry in 1982, for his work on the structure of nucleic acid-protein complexes, which he started with Franklin.

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