Question

Arrange the steps involved in Gram-stain procedure:
(A) Staining with Crystal Violet
(B) Staining with Gram’s Iodine
(C) Decolorization
(D) Staining with Safranine
Choose the correct answer from the options given below:

• A. (A), (B), (C), (D)
• B. (A), (B), (D), (C)
• C. (B), (A), (D), (C)
• D. (C), (B), (D), (A)

Hint:

Understand the sequence of steps and their purpose in the Gram-staining process to differentiate between Gram-positive and Gram-negative bacteria.

Answer 1

The Correct Option is A

The Gram-stain procedure includes:
1. Crystal Violet Staining: This primary stain attaches to peptidoglycan in bacterial cell walls.
2. Gram’s Iodine Application: Iodine serves as a mordant, creating a complex with Crystal Violet and strengthening its bond.
3. Decolorization: Alcohol or acetone removes the stain from Gram-negative bacteria due to their thinner peptidoglycan layer.
4. Safranine Staining: This counterstain colors Gram-negative bacteria pink, while Gram-positive bacteria retain their purple hue.