X-ray topography of lysozyme crystals

Laue topography of orthorhombic and tetragonal lysozyme crystals has been carried out using synchrotron radiation. A water filter, 5 mm in thickness, was effective to avoid radiation damage. The orthorhombic crystals grown at 38°C showed strong asterisms. The tetragonal crystals grown at room temperature and the orthorhombic crystals incubated at room temperature from small crystals emerging at 38°C did not show asterism but showed white bands in black Bragg spots resembling the shape of the crystals. Straight bands directed to the radial directions of the diffraction pattern, wavy bands parallel to the c-axis of the orthorhombic crystal and straight twisted bands parallel to several directions in the tetragonal crystal were also observed.