Crystallographic studies of chemically modified hemoglobins and myoglobins are reviewed. Since each subunit of these proteins is composed of polypeptide chain (globin) and heme, two kinds of modification were applied ; that of the globin and of the heme group. The relation between structural change and oxygen affinity has been understood by comparison of the structures of myoglobins reconstituted with a variety of modified hemes with that of native one.
Cothordoluminescence (CL) detection system was built up for a transmission electron microscope with scanning units, which enable us to take high-resolution CL images of crystal defects together with crystallographic information. Luminescence or non-luminescence centers localized at dislocations in III-V compound semiconductors, diamond and magnesium oxide were observed using this system. Their natures were studied through the analyses of the TEM and monochromatic CL images and spectral information of the CL light.