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 The controversy arose from Watson and Crick using some of Franklin's unpublished data—without her consent—in their construction of the double helix model of DNA.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
Solenoid (DNA) Solenoid (DNA) The solenoid structure of chromatin is a model for the structure of the 30 nm fibre. It is a secondary chromatin structure which helps to package eukaryotic DNA into the nucleus. Chromatin was first discovered by Walther Flemming by using aniline dyes to stain it. In 1974, it was first proposed by Roger Kornberg that chromatin was based on a repeating unit of a histone octamer and around 200 base pairs of DNA. The solenoid model was first proposed by John Finch and Aaron Klug in 1976. They used electron microscopy images and X-ray diffraction patterns to determine