Lipofuscin is a tawny pigment with a granular appearance, consisting of fat-containing residues and lysosomal digests, and is thought to be produced by the oxidation of lipids and lipoproteins. Lipofuscin oxidation occurs slowly and gradually, so the pigment will show different staining reactions, different colors, and variations in shape and size. Lipofuscin can be found in the liver, kidney, myocardium, adrenal glands, nerve cells and ganglion cells, etc., and is mostly distributed around the nucleus of cells.

Since lipofuscin is formed gradually by the slow oxidation of lipids and lipoproteins, and the pigment is at a different level of oxidation, the histochemical reaction will be different when applying the technique to confirm it, therefore, it is recommended to apply a number of different techniques to verify that the pigment is lipofuscin. Some of the commonly used methods are the PAS method, Schmorl's high iron - ferricyanide reduction method, Long Ziehl-Neelsen method, Gomori aldehyde reddening method, and Masson-Fontana silver method.