History of molecular biology Crick and Watson built physical models using metal rods and balls, in which they incorporated the known chemical structures of the nucleotides, as well as the known position of the linkages joining one nucleotide to the next along the polymer. At King's College Maurice Wilkins and Rosalind Franklin examined X-ray diffraction patterns of DNA fibers. Of the three groups, only the London group was able to produce good quality diffraction patterns and thus produce sufficient quantitative data about the structure. In 1948 Pauling discovered that many proteins included helical (see alpha helix) shapes. Pauling had deduced this structure from X-ray
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 the unpublished results and ideas" of Wilkins and Franklin.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