Crystal Violet is a rapid screening method for which substance?

• A. Amyloid
• B. Collagen
• C. Mucin
• D. Nuclei

Answer: (A)

Crystal Violet is used as a quick screening stain to detect amyloid deposits in tissue. Amyloid binds the basic dye readily, so areas with amyloid take up the violet stain prominently, making them easy to flag for further confirmation. If this rapid screen is positive, the specimen is then tested with Congo red and viewed under polarized light to look for the characteristic apple-green birefringence, which confirms amyloid. Other tissues components—collagen, mucin, and nuclei—have different staining patterns and are identified best with other stains (for example, collagen with Masson’s trichrome, mucin with Alcian blue or mucicarmine, and nuclei with hematoxylin).