DNA and the Molecular Basis of Life

The three-dimensional structure of deoxyribonucleic acid (DNA), the molecule that carries hereditary information in nearly all living organisms, was determined in early 1953 by the American biologist James Watson and the British physicist Francis Crick, working at the Cavendish Laboratory of the University of Cambridge. Watson and Crick proposed that DNA takes the form of a double helix, two intertwined strands running in opposite directions, held together by pairs of chemical bases, adenine with thymine and guanine with cytosine, whose complementary pairing immediately suggested a mechanism by which genetic information could be copied and passed on during cell division. Their model, published in a brief paper in the journal Nature on 25 April 1953, drew critically on experimental data produced by two other researchers at King's College London, the physicist Maurice Wilkins and the chemist Rosalind Franklin, whose X-ray diffraction studies of DNA fibers provided key measurements that Watson and Crick used to build and confirm their structure. Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine in 1962 for the discovery.