Viral hepatitis is an infectious disease caused by hepatitis viruses with degeneration and necrosis of liver parenchymal cells as the main lesion. Hepatitis B virus is the hepatitis B virus that spreads worldwide, and HBsAg is present in the liver cytoplasm. Currently, HBsAg and HBcAg of hepatitis B virus can be displayed by immunohistochemical methods, and the methods for displaying HBsAg include Shikata lichen red, aldehyde magenta, and Victoria blue.

Virus staining solution (lichen red method) is easy to operate and has high specificity, but the staining effect may be varied by different batches of raw materials, and the possible mechanism is that the lichen red binds to the disulfide bond of cystine in HBsAg, and then develops the color.