Isoelectric focusing of catalase isozymes of tissues, utilizing an innovative overlay immunoisoelectric focusing procedure, will be carried out during the next grant peiod. Highly reproducible and statistically valid data on erythrocytic catalase have been obtained during the past year from peripheral blood specimens of healthy volunteers. Attempts will be made to determine the isoelectric focusing patterns of human leukocytic catalase in patients with acute and chronic granulocytic leukemias and will be contrasted with those of healthy individuals. BIBLIOGRAPHIC REFERENCE: Yang, H-Y, and Nishimura, E.T. Age-related paracrystalline inclusions in mouse bone marrow reticular cells. J. Reticuloendothelial Soc., December 15, 1976.