The Purpose of a Mordant in the Gram Stain Is

Question

The purpose of a mordant in the Gram stain is to
A)remove the simple stain.
B)make the bacterial cells larger.
C)make the flagella visible.
D)prevent the crystal violet from leaving the cells.
E)make gram-negative cells visible.

Accepted Answer

The purpose of the mordant in the Gram stain is to prevent the crystal violet from leaving the cells. The mordant, typically iodine, forms a complex with the crystal violet, making it less likely to be washed away during the decolorizing step. This allows the differentiation of gram-positive and gram-negative bacteria based on their differential ability to retain the crystal violet stain after decolorization.