The Succinate Dehydrogenase (SDH) Assay Kit utilizes DCPIP, a blue-colored redox dye, to measure SDH activity in samples. When SDH converts succinate to fumarate, it generates FADH2, which transfers electrons to an electron acceptor. In this assay, the electrons are transferred to DCPIP, which becomes reduced and changes color. This color change can be measured with a spectrophotometer at an absorbance of 600 nm.