The library remains closed, along with the rest of Wellcome Collection

Following the latest government advice, we remain temporarily closed until further notice. Find out more on the Wellcome Collection website.

Wellcome uses cookies. Read our policy.

Codebreakers: Makers of Modern Genetics

The Rosalind Franklin papers

Rosalind Franklin was a brilliant X-ray crystallographer whose photograph of a fibre of DNA was critical to James Watson and Francis Crick's discovery of the double helix.

Open the Franklin archive

View digitised items online

Collection overview

The discovery of the structure of DNA at Cambridge in 1953 was the most important contribution to biology of the 20th century. Rosalind Franklin's work on DNA, conducted at King's College London, played a critical role. Her X-ray studies of DNA provided data that helped to bring into being the theoretical model constructed by Watson and Crick.

The Cambridge researchers obtained access to these data without her knowledge. Her colleague at King's, Maurice Wilkins, showed her photograph of the 'B' form of DNA to James Watson early in 1953, when she was preparing to leave King's to start a new project at Birkbeck College, London. Watson describes his reaction in 'The Double Helix': "The instant I saw the picture my mouth fell open and my pulse began to race... the black cross of reflections which dominated the picture could arise only from a helical structure... mere inspection of the X-ray picture gave several of the vital helical parameters."

Summary of main conclusions
Formation of H-bonds
from 'Brief summary of main conclusions & result on DNA'
View online

The papers in this collection, which are held at Churchill College, Cambridge, include the laboratory notebooks in which Franklin set out her findings and noted her own thoughts about the structure. They contain annotations made ten years after her untimely death by her colleague Aaron Klug, who published a paper in 'Nature' in 1968 showing that she had been ahead of Watson and Crick in establishing key parameters of the structure.

DNA was only an interlude in Franklin's career. She had previously made important contributions to the study of carbon at the British Coal Utilisation Research Association; subsequently she used her crystallographic skills to reveal the hollow centre of the tobacco mosaic virus particle (TMV), and to trace the helical form of its genetic material within this cylinder. The collection includes little on her carbon work, but there is a comprehensive set of files on TMV.

Correspondence with many of the leading figures of 20th-century molecular biology, including Watson, Crick and Sydney Brenner, is contained in the collection: it shows that, contrary to myth, she enjoyed cordial professional and personal relationships with the Cambridge researchers until her death. Franklin's many letters to her parents and other relatives have been kept in family hands, although they have previously been made available to biographers including Brenda Maddox ('The Dark Lady of DNA', 2002) and were used extensively by her sister Jenifer Glynn in her own memoir, 'My Sister Rosalind Franklin' (2012).


Rosalind Elsie Franklin (1920-1958) set her heart on a scientific career from an early age, and pursued it with the imagination and determination she brought to all her activities. She was one of five children of a London banker from a Jewish family with extensive political and cultural connections.

Fibre diagram
Fibre diagram of the crystalline structure of DNA
R Franklin and R Gosling, c. 1953
View online

She studied natural sciences at the University of Cambridge, and completed a PhD in physical chemistry partly through studying 'the holes in coal' for the British Coal Research Utilisation Association. Thanks to a wartime encounter with the French refugee physicist Adrienne Weill, she moved to Paris in the postwar years to pursue her studies of carbon using the technique of X-ray diffraction.

The important original research she published during this period has been all but eclipsed in the public imagination by the two unhappy years she then spent at King's College London working on DNA. Because of a misunderstanding about their respective roles, and a total mismatch between their personalities, she and Maurice Wilkins were not able to combine their expertise, but worked grimly apart and barely spoke to one another. Even in these unpromising conditions, Franklin and her research student Raymond Gosling produced the critical X-ray photographs that led to the successful solution of the structure of the molecule.

In 1953 Franklin moved to the more congenial environment of J D Bernal's crystallography department at Birkbeck College. There she made important advances in the structure of viruses. She remained friendly with Francis Crick and his wife, Odile, even staying at their home when recovering from chemotherapy for the ovarian cancer that was diagnosed when she was 37. She died the following year.

Originals held by...

This material has been provided by Churchill Archives Centre, Churchill College, Cambridge where the originals may be consulted.

The results suggest a helical structure…containing probably 2, 3 or 4 coaxial nucleic acid chains per helical unit and having the phosphate groups near the outside.

Rosalind Franklin, from a report submitted to the Medical Research Council, February 1952

Digitised book

Tobacco mosaic virus

Tobacco mosaic virus

in Molecular Basis of Virololgy

In The Timeline

1952: Rosalind Franklin produces ‘Photo 51’ of DNA

Rosalind Franklin produces ‘Photo 51’ of DNA

Open the timeline

Back to top

More from the archives