An assay for the middle portion of the mitochondrial electron transport chain (ETC) is described. Succinate: cytochrome c reductase (SCR) activity is measured in mitochondria isolated from human leukocytes, platelets, and cultured fibroblasts. The activity is blocked by antimycin A indicating specificity for the mitochondrial inner membrane ETC. SCR values in normal and Friedreich's ataxia patients were similar. This assay may be helpful in evaluating acquired and heritable disorders of mitochondrial metabolism.
ASJC Scopus subject areas