Rosalind Franklin and DNA Rosalind Franklin and DNA Rosalind Franklin and DNA is a biography of an English chemist Rosalind Franklin (1920–1958) written by her American friend Anne Sayre in 1975. Franklin was a physical chemist who made pivotal research in the discovery of the structure of DNA, known as "the most important discovery" in biology. DNA itself had become "life's most famous molecule". While working at the King's College London in 1951, she discovered two types of DNA called A-DNA and B-DNA. Her X-ray images of DNA indicated helical structure. Her X-ray image of B-DNA (called Photo 51) taken in 1952 became the
Francis Crick funded by the MRC. It is also not clear how important Franklin's unpublished results from the progress report actually were for the model-building done by Watson and Crick. After the first crude X-ray diffraction images of DNA were collected in the 1930s, William Astbury had talked about stacks of nucleotides spaced at 3.4 angström (0.34 nanometre) intervals in DNA. A citation to Astbury's earlier X-ray diffraction work was one of only eight references in Franklin's first paper on DNA. Analysis of Astbury's published DNA results and the better X-ray diffraction images collected by Wilkins and Franklin revealed the helical nature