Synchrotron X-ray topography is one of the most powerful methods for the observation and characterization of crystal defects, especially dislocations, in crystals. For protein crystals, larger crystals with millimeter size are required to obtain clear topographic contrasts of dislocations. In this review, various types of dislocations such as straight, loop, and curved ones are identified for large crystals of hen egg-white lysozyme and glucose isomerase (GI). Pendellösung fringes which have been seen in high quality Si crystals are also observed in GI crystals with high quality. In addition, digital topography with X-ray CCD camera is shown with the analysis of local rocking curves in protein crystals. The digital topography shows promising for the evaluation of not only the distribution but also the misorientation of subgrains with strain in protein crystals.
