A sensitive colorimetric assay for mitochondrial alpha-glycerophosphate dehydrogenase

A simple reproducible assay for mitochondrial α-glycerophosphate dehydrogenase (GPD) has been described. It takes advantage of the ability of 2-p-iodo-3-p-nitro-5-phenyl tetrazolium chloride (INT) to directly accept electrons from the dehydrogenase. The assay will accurately measure the enzyme using 20 μg of mitochondrial protein, but it could be scaled down further using smaller volumes and microcuvettes.