Rosalind Franklin

Born on 25 July 1920 in London, Rosalind Franklin was a pioneering x-ray crystallographer who made essential contributions toward determining the structure of DNA. Franklin received a PhD in physical chemistry from Cambridge in 1945. Her work in the early 1950s exposed elusive structural details about the composition and structure of deoxyribonucleic acid (DNA), which encodes genetic information for all single-celled and multicellular organisms on Earth. Franklin determined the density of DNA and its helical shape, and her photographs proved crucial to James Watson and Francis Crick’s double-helix model. In April 1953 a paper by Franklin appeared third in a series of studies in Nature describing DNA structure, with Watson and Crick’s paper appearing first. That’s just one of the reasons that Franklin’s contributions have been overlooked over the years. You can read more about her pivotal work in a March 2003 Physics Today article by biological sciences professor Lynne Elkin. Franklin died in 1958 from cancer at age 37.

Date in History: 25 July 1920