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
Maurice Wilkins deduced from her X-ray diffraction data. Watson and Crick published their proposed DNA double helical structure in a paper in the journal "Nature" in April 1953. In this paper Watson and Crick acknowledged that they had been "stimulated by... the unpublished results and ideas" of Wilkins and Franklin. The first Watson-Crick paper appeared in "Nature" on 25 April 1953. The members of the Cambridge and King's College laboratories agreed to report their interlocking work in three papers with continuous pagination in "Nature". Sir Lawrence Bragg, the director of the Cavendish Laboratory, where Watson and Crick worked, gave a talk at