Question

The purpose of a mordant in the Gram stain is to:a. remove the simple stain. b. make gram-negative cells visible. c. prevent the crystal violet from leaving the cells. d. make the bacterial cells larger. e. make the flagella visible.

Answer 1

Answer:

c. Prevent crystal violet from leaving the cells

Explanation:

Gram Staining:

• Gram staining is a staining techniques used for the identification of bacteria in microbiological studies.
• Gram staining uses crystal violet as the primary stain. It complexes with the peptidoglycan cell wall of Gram positive bacteria giving them a purple color.
• An iodine mordant is also used that forms a crystal violet-iodine complex that fixes the crystal violet dye to the cell wall. This prevents the Gram positive cell walls from being decolorized by the application of alcohol.
• A counter stain, safranin is then applied that stains Gram negative bacteria pink.