Metabolic mapping. Localization of activity of SDH (A,B), NAD+-dependent IDH (C,D) and NADP+-dependent IDH (E,F). The blue color represents the activity of the respective dehydrogenases after 15 minutes of incubation at 37°C. Note the high activities of mitochondrial dehydrogenases in E478 xenograft as compared with the E434 xenograft. Bar = 100 μm.