Biomolecular structure chemical probing, hydroxyl radical probing, nucleotide analog interference mapping (NAIM), and in-line probing. Protein and nucleic acid structures can be determined using either nuclear magnetic resonance spectroscopy (NMR) or X-ray crystallography or single-particle cryo electron microscopy (cryoEM). The first published reports for DNA (by Rosalind Franklin and Raymond Gosling in 1953) of A-DNA X-ray diffraction patterns—and also B-DNA—used analyses based on Patterson function transforms that provided only a limited amount of structural information for oriented fibers of DNA isolated from calf thymus. An alternate analysis was then proposed by Wilkins et al. in 1953 for B-DNA X-ray diffraction and scattering
Francis Crick some of which were performed by Crick. The details of the code came mostly from work by Marshall Nirenberg and others who synthesized synthetic RNA molecules and used them as templates for "in vitro" protein synthesis. Nirenberg first announced his results to a small audience in Moscow at a 1961 conference. Crick's reaction was to invite Nirenberg to deliver his talk to a larger audience. An enduring controversy has been generated by Watson and Crick's use of DNA X-ray diffraction data collected by Franklin and Wilkins. The controversy arose from the fact that some of Franklin's unpublished data were used