Information: The Orcein Stain may be used in histology procedures for the visualization of Hepatitis B surface Antigen (HBsAg), elastic fibers, and copper associated proteins. HBsAg appears as irregular shaped aggregates in the cytoplasmic region of the cells. This reagent may be used on formalin-fixed, paraffin-embedded sections. HBsAg: Dark Red/Brown Elastic Fibers: Dark Red/Brown Copper Assoc. Proteins: Dark Red/Brown Background: Light Reddish/Purple