How is x ray crystallography involved with dna

How an X-ray diffraction pattern is created and how the DNA X-ray diffraction pattern can be interpreted to give the dimensions. It is know as the B-form. It was clearer than the other X-ray patterns because water was included in the DNA sample. Both James Watson and Francis Crick were struck by the simplicity and symmetry of this pattern.

The distinctive "X" in this X-ray photo is the telltale pattern of a helix. Origin of Cells 6. Cell Division 2: Molecular Biology 1. Metabolic Molecules 2. Water 3. Protein 5. Enzymes 6. Cell Respiration 9. Photosynthesis 3: Genetics 1. Genes 2. Chromosomes 3. Meiosis 4. Inheritance 5. Genetic Modification 4: Ecology 1. Energy Flow 3. Carbon Cycling 4. Climate Change 5: Evolution 1. Opinion and evidence vary as to how and when Franklin interpreted her evidence as bearing on the form of the DNA molecule.

When she decided to leave Kings College, Franklin delivered her notebooks including Photo 51 to Wilkins, with instructions to use them as he wished. Wilkins showed Photo 51 to Watson, who immediately realized that the X -structure implied two strands. In combination with his work on model building, the familiar " D ouble Helix " with paired bases on the inside quickly emerged.

The model and crystallographic evidence were published as twin papers in Nature. Wilkins had by then amassed a great deal of additional crystallographic evidence for the double-helical structure. Franklin had moved on to other crystallographic studies, notably the structure of Tobacco Mosaic and Polio viruses.