There are various methods for staining mucus material, such as AB-PAS staining, mucus HID-AB staining, standard alcian blue staining, etc. Most of the above methods utilize the principle that alcian blue (Alcian) is a cationic dye that can bind to acidic groups, i.e., alcian blue forms insoluble complexes with anionic groups contained in the tissue, such as carboxyl groups and sulfate, however, the above methods are not specifically designed to reveal Neutral mucus material.

Mucus carmine staining is mainly used to show neutral mucus material, but can also show acidic mucus material and new cryptococcus, especially suitable for showing gastric and epithelial mucus, and clinically, it is mostly used to identify mucus-secreting epithelial carcinoma.