The detection of haptoglobin in bloodstains is carried out by extracted blood in tris-citrate buffer and run in starch gel electrophoresis in NaOH-boric and stained with benzidine-hydrogen peroxide. The persistence of haptoglobin varies according to the supporting medium and environment (heat, moisture) and also to its phenotypes. The duration for detection of haptoglobin in bloodstains is between 1 and 7 days.
