Linus Pauling showed evidence for a helix and planar base stacking along the helix axis. Early in 1953 Watson and Crick proposed a correct structure for the DNA double helix. Pauling later cited several reasons to explain how he had been misled about the structure of DNA, among them misleading density data and the lack of high quality X-ray diffraction photographs. During the time Pauling was researching the problem, Rosalind Franklin in England was creating the world's best images. They were key to Watson's and Crick's success. Pauling did not see them before devising his mistaken DNA structure, although his assistant Robert
Timeline of United States discoveries chloride 1936 Elliptical galaxies 1936 Muons 1936 Vitamin E 1936 Sodium thiopental 1937 Niacin 1937 Electron capture 1938 Fluropolymers 1938 Animal echolocation 1938 Carme 1938 Lysithea 1940 Plutonium 1942 Cyanoacrylate 1943 Streptomycin 1944 Americium 1944 Curium 1946 Cloud seeding 1948 Warfarin 1948 Miranda 1948 Serotonin 1948 Tetracycline 1949 Nereid 1949 Berkelium 1950 Californium 1951 Barium stars 1951 Ananke 1952 Polio vaccine 1952 Einsteinium 1952 Rapid eye movement 1953 DNA structure In 1953, based on X-ray diffraction images and the information that the bases were paired, James D. Watson along with Francis Crick co-discovered what is now widely accepted as the