Orcein Stain Kit is a stain technique used to identify viral inclusion bodies of hepatitis B surface antigen (HBsAG) and copper-associated proteins in tissue sections on the Artisan Link and Artisan Link Pro Staining Systems. Virus particles inside host cells are called viral inclusion bodies. A hepatitis B virus lies on the surface of the virus particle. HBsAG can be detected by using the Orcein staining method. The antigen appears as fine granules either diffusely spread throughout the cytoplasm or concentrated in the cytoplasm peripheral to the sinusoid space. Copper-associated proteins when in excessive pathologic amounts, such as Wilson's disease and some forms of cirrhosis, can be detected by using the Orcein staining method. HBsAG/elastin fibers: dark reddish brown, copper-associated protein: dark red-purple and background: pale pink-pink.