Contemporary Science Issues Lesson 3: DNA Discovery Main Activity: Timeline (easier version) 4 cards per page © 2006 Gatsby Technical Education Projects

25 July 1920 Rosalind Franklin born Rosalind worked for British Coal research, looking at the structures of coal and graphite. Gained PhD in – 41 Rosalind went to Cambridge to study science Rosalind moved to Paris to research structure of molecules using a new technique, X ray diffraction and became expert at producing photographs of the patterns molecules make.

8 January 1951 Took up a research post at King’s College, London under J.T. Randall. Asked to use her skills at X-ray diffraction to study DNA. Late January 1951 Her immediate supervisor at King’s, Maurice Wilkins, returned from holiday and presumed she was a laboratory technician, not a skilled scientist. They took an instant dislike to each other. Rosalind and Wilkins were very different characters. 21 November 1951 At a conference in London on the structure of DNA, Rosalind gave a talk about her work. James Watson was present and afterwards wrote “I wondered how she would look if she took off her glasses and did something … with her hair”. October/November 1951 Wilkins visited his old friend, Francis Crick, at the Cavendish Laboratory in Cambridge. They discussed all the work around the world trying to work out the structure of DNA, including the work at Rosalind’s laboratory. James Watson, a friend of Crick, was also present.

May 1952 Rosalind took the best picture yet of DNA – Photo 51. She did not write up her results for publication because she wanted to do further work and get more data. 30 January 1953 Watson went to King’s and saw Randall and Wilkins, who showed him Rosalind’s Photo 51. Later, Watson said “The instant I saw the picture my mouth fell open and my pulse began to race”. 16 April 1958 Rosalind Franklin died of ovarian cancer, probably caused by the exposure she had to radiation when carrying out her work James Watson, Francis Crick and Maurice Wilkins received the Nobel Prize for their work on the structure of DNA.

7 March 1953 Using information from various sources, including Rosalind’s photo, Watson and Crick finally realised that the structure of DNA was a double helix and built the first accurate model of DNA. April 1953 Watson and Crick published their work in the journal Nature February 1953 Rosalind began making models and came very close to working out the structure Photo 51

Watson and Crick’s model of the double helix DNA