Weak Mucin Staining in a Mucicarmine Stain

Situation: mucin in control slide poorly stained

Possible causes:

(1) low quality carmine powder

(2) deterioration of the working mucicarmine solution

(3) storage of mucicarmine stock solution at room temperature

(4) prolonged storage of working or stock solution

Solution to staining problems:

(1) discard working solution

(2) use only high-quality reagents

(3) discard stock solution if improperly stored

(4) ensure that all solutions have an expiration date