A question about staining bacteria??

Question

What is the function of a mordant?

I know that a mordant is used in gram staining, but I can't figure out what it's exact function is?

Answer 1

It is used so the dye will stain, it will bind the dye so that it stays attached to the bacteria in a chemical bond.

Answer 2

A mordant is a substance used to set dyes on fabrics by forming an insoluble compound with the dye. It may be used for dyeing fabrics, or for intensifying stains in cell or tissue preparations. A mordant is either inherently colloidal or produces colloids and can be either acidic or alkaline.