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
James Watson determined that their results were inconclusive and could not specifically identify the newly labeled molecules as DNA. Watson never developed a constructive interaction with Kalckar, but he did accompany Kalckar to a meeting in Italy, where Watson saw Maurice Wilkins talk about his X-ray diffraction data for DNA. Watson was now certain that DNA had a definite molecular structure that could be elucidated. In 1951, the chemist Linus Pauling in California published his model of the amino acid alpha helix, a result that grew out of Pauling's efforts in X-ray crystallography and molecular model building. After obtaining some results from