Which tissues are recommended for QC in Mayer's Mucicarmine?

• A. Colon, small intestine, or appendix
• B. Brain
• C. Liver
• D. Skin

Answer: (A)

Mayer's Mucicarmine specifically highlights acidic mucins in goblet cells, turning mucin-rich tissues a magenta color. A good QC tissue for this stain must contain goblet cell mucin so you can see the expected positive reaction clearly. Colon, small intestine, and appendix all have abundant goblet cells that produce mucin, providing a reliable, consistent magenta stain when this method is working properly. Brain, liver, and skin don’t have mucin-rich goblet cells in the same way, so they wouldn’t demonstrate the stain’s intended positive reaction, making them unsuitable as QC tissues for this stain.