Beibrich scarlet is used in which staining procedure?

• A. Masson trichrome
• B. Gomori trichrome
• C. Verhoeff
• D. MGP

Answer: (A)

Beibrich scarlet is used in Masson trichrome to stain muscle fibers and cytoplasm red, creating a strong contrast with collagen which is later stained blue by the counterstain. In this procedure, after the nuclear stain, Beibrich scarlet (often combined with acid fuchsin) binds to cytoplasmic elements, giving them a bright red color. A subsequent differentiating step and the blue counterstain separate the connective tissue, so tissue appears with muscle in red, collagen in blue, and nuclei dark. This specific red dye combination is characteristic of Masson trichrome, whereas the other stains target elastic fibers or use different dye systems.