Photo 51 and the discovery of DNA's structure

Dr Franklin joined the laboratory of John Randall at King’s in 1950 with a PhD from Cambridge and X-ray diffraction experience in Paris. At King’s, by controlling the water content of the DNA specimens, she showed that the molecule could exist in two forms (A and B). In May 1952 she and PhD student Ray Gosling captured the image of the B form that supported the modelling of DNA - 'photo 51'.

Photo 51 is one of the world’s most important photographs, demonstrating the double-helix structure of deoxyribonucleic acid: the molecule containing the genetic instructions for the development of all living organisms. Franklin’s image confirmed James Watson and Francis Crick of the University of Cambridge's hypothesis that DNA had a double helical structure, enabling them to build the first correct model of the DNA molecule in 1953.

A paper by Franklin and Gosling, together with one by Dr Maurice Wilkins and colleagues from King’s, accompanied the announcement of Watson and Crick’s momentous discovery in Nature in May 1953.

After leaving King’s in 1953 to work at Birkbeck College, Franklin worked on the structure of the tobacco mosaic virus and of RNA (ribonucleic acid, a nucleic acid present in all living cells). Between 1953 and her death in 1958, aged only 37, she published 17 papers on viruses, and her group laid the foundations for structural virology. 

She is described as a rigorous, careful and intelligent experimentalist, who insisted on robust and carefully collected data. She was a passionate scientist who believed that "science and everyday life cannot and should not be separated."

Watson, Crick and Wilkins were recognised with the Nobel Prize for their discovery of DNA's structure, but the prize is not awarded posthumously, contributing to the exclusion of Franklin's contributions. In recent years, however, Franklin's crucial contributions to the DNA discovery and science more broadly have become more widely recognised.

The Royal Society has an annual award named after her and, in 2015, the story of her discovery was brought to life in London’s West End in the play, Photograph 51. Her name is also immortalised by King’s Franklin Wilkins Building at Waterloo Campus, as well as The Rosalind Franklin University of Medicine and Science in Chicago. Her work provided the basis for modern understanding of genes.

Photographs courtesy of King’s College London Archives.