Assay of succinate dehydrogenase activity by a colorimetric-continuous method using iodonitrotetrazolium chloride as electron acceptor.

A spectrophotometric assay method for determining succinate dehydrogenase activity is described in which iodonitrotetrazolium chloride is used as a final electron acceptor. The enzyme activity is determined by measuring the formation of formazan due to the tetrazolium salt reduction. The assay is continuous, rapid, simple, and sensitive, and may be used in the determination of enzyme activity either in tissue homogenates or as a marker of the mitochondrial fraction in cell fractionation procedures.