Non-helical models of DNA structure the top of this article, or there could be an equal number of right-handed and left-handed twists, as in the Rodley structure below. The abbreviation "TN", to be used to refer to any DNA structure whose strands are topologically non-linked, has been proposed. The double-helix model of DNA structure was first published in the journal "Nature" by James D. Watson and Francis Crick in 1953 with further details in 1954.) Their work was based upon the crucial X-ray diffraction image of DNA - labeled as "Photo 51" - from Rosalind Franklin in 1952, followed by her more highly clarified DNA
James Watson his phage and other experimental research conducted at Indiana University, Statens Serum Institut (Denmark), CSHL, and the California Institute of Technology, Watson now had the desire to learn to perform X-ray diffraction experiments so he could work to determine the structure of DNA. That summer, Luria met John Kendrew, and he arranged for a new postdoctoral research project for Watson in England. In 1951 Watson visited the Stazione Zoologica 'Anton Dohrn' in Naples. In mid-March 1953, Watson and Crick deduced the double helix structure of DNA. Crucial to their discovery were the experimental data collected at Kings College — mainly