A preliminary study of space- and ground-grown insulin crystals by X-ray diffraction and by light scattering tomography

For the first time, both X-ray diffraction and light scattering tomography were used to study the same set of space- and ground-grown protein crystals. X-ray diffraction of the insulin crystals grown from T6 insulin solutions by temperature reduction showed that space-grown crystals diffract to higher resolution then those grown on the ground. The light scattering tomographs revealed that the space-grown crystals contained very few spherical micro-defects while the ground-grown ones had large numbers of extended micro-defects and dislocations. The tomographs also gave insight into the methods of defect formation. This study marks the beginning of qualification of light scattering tomograph as a tool for determining the suitability of a protein for use in X-ray diffraction studies.