Francis Crick DNA crystals revealed to Crick that the two DNA strands were antiparallel. In January 1953, Watson was shown an X-ray photograph of B-DNA (called photograph 51), by Wilkins. Wilkins had been given photograph 51 by Rosalind Franklin's Ph.D. student Raymond Gosling. Wilkins and Gosling had worked together in the Medical Research Council's (MRC) Biophysics Unit before director John Randall appointed Franklin to take over both DNA diffraction work and guidance of Gosling's thesis. It appears that Randall did not communicate effectively with them about Franklin's appointment, contributing to confusion and friction between Wilkins and Franklin. In the middle of February
Francis Crick to peptide bonds in proteins and the structure of nucleotides in DNA. In 1951 and 1952, together with William Cochran and Vladimir Vand, Crick assisted in the development of a mathematical theory of X-ray diffraction by a helical molecule. This theoretical result matched well with X-ray data for proteins that contain sequences of amino acids in the alpha helix conformation. Helical diffraction theory turned out to also be useful for understanding the structure of DNA. Late in 1951, Crick started working with James Watson at Cavendish Laboratory at the University of Cambridge, England. Using "Photo 51" (the X-ray diffraction results