The histochemical demonstration of the activity of this enzyme is achieved by incubation of fresh frozen sections with a succinate substrate in the presence of a tetrazolium compound. Tetrazoliums are water-soluble compounds employed in histochemistry as redox indicators.
Enzymatic activity releases hydrogen from colored compounds.
Commonly used tetrazoliums include nitro blue the substrate, and the released hydrogen is transferred to the tetrazolium. With the addition of hydrogen, the tetrazolium is converted to purple-blue formazan pigment marking the site of enzyme activity. Snap frozen human striated muscle. For a negative control, eliminate sodium succinate from the incubating medium. A stock solution may be kept refrigerated for two weeks and still be effective.