Publisher Information: 1953. Wilkins, Maurice (1916- ) and Randall, J[ohn] T. (1905-84). Crystallinity in sperm heads: Molecular structure of nucleoprotein in vivo. Offprint from Biochimica et biophysica acta 10 (1953). 192-193pp. Illustrated with an x-ray photograph. 242 x 167 mm. Without wrappers as issued. Fine apart from slight creasing. Book Id: 38473
First Separate Edition. Wilkins, a member of John Randall's biophysics research program at King's College, London, began performing x-ray diffraction studies of DNA in the early 1950s after accidentally discovering how to spin the very thin uniform fibers of DNA required for this type of analysis. In 1950 he and Raymond Gosling became the first to obtain diffraction photographs of DNA in crystalline form, but due to various difficulties did not continue with this line of research until 1952, by which time Watson and Crick had entered the picture. By this time there was sufficient evidence to indicate that the structure of the DNA molecule was probably helical, but it was still unclear as to whether such a structure occurred within the cell or was simply an artifact of preparation. Working with squid sperm, "which occurs in bundles remarkable for the perfection of the parallel array of cells," Wilkins performed x-ray studies "that showed, he believed, that DNA in intact cells was helical, too" (Judson, pp. 95-96).