Sudan Black B, a fat-soluble diazo dye, serves as a histochemical stain, particularly effective for staining neutral triglycerides and lipids [1].

Sudan Black B works in frozen material and can be complementarily used with SA-β-gal when investigating senescence. Sudan Black B is a highly lipophilic agent with a high affinity for the lipid compartment of lipofuscin. The positive Sudan Black B-lipofuscin reaction reveals blue-black intracellular granules in cells and frozen tissues, and brown to black granules in FFPE tissues under the light microscope.