SDH catalyzes the dehydrogenation of succinate to fumarate, with electron transport materials transferring electrons to 2, 6-dichlorophenol indiophenol (DCPIP). Then, the reduced DCPIP is reduced to the oxidized DCPIP, which has a characteristic absorption peak at 600 nm. Therefore, the activity of SDH can be quantified by measure the change OD value at 600 nm.