X-ray diffraction patterns obtained of A-form DNA
These images of Structure A were taken by Franklin and Gosling using the new micro-camera Spears-Ehrenberg x-ray tube single fibre method. Franklin's expertise in crystallography greatly improved the control of variables such as the humidity levels and clearer pictures emerged. These experiments with the A-form showed a marked shrinkage in structure as humidity was reduced. During these experiments with the alteration in humidity they discovered that the process was reversible.