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
Molecular models of DNA community. After DNA has been separated and purified by standard biochemical methods, one has a sample in a jar much like in the figure at the top of this article. Below are the main steps involved in generating structural information from X-ray diffraction studies of oriented DNA fibers that are drawn from the hydrated DNA sample with the help of molecular models of DNA that are combined with crystallographic and mathematical analysis of the X-ray patterns. A paracrystalline lattice, or paracrystal, is a molecular or atomic lattice with significant amounts (e.g., larger than a few percent) of partial disordering of