James Watson diffraction data collected by Rosalind Franklin and Raymond Gosling. The controversy arose from Watson and Crick using some of Franklin's unpublished data—without her consent—in their construction of the double helix model of DNA. Franklin's experimental results provided estimates of the water content of DNA crystals and these results were consistent with the two sugar-phosphate backbones being on the outside of the molecule. Franklin personally told Crick and Watson that the backbones had to be on the outside, which was a crucial piece of information; before then, Linus Pauling and Watson and Crick had generated erroneous models with the chains inside
Molecular models of DNA omit both water and ions dynamically bound to B-DNA, and are thus less useful for understanding the dynamic behaviors of B-DNA "in vivo". The physical and mathematical analysis of X-ray and spectroscopic data for paracrystalline B-DNA is thus far more complex than that of crystalline, A-DNA X-ray diffraction patterns. The paracrystal model is also important for DNA technological applications such as DNA nanotechnology. Novel methods that combine X-ray diffraction of DNA with X-ray microscopy in hydrated living cells are now also being developed. There are various uses of DNA molecular modeling in Genomics and Biotechnology research applications, from DNA repair