Question

In the process of Gram staining the fixed bacterial smear is subjected to which of the following staining reagents?

• A. Crystal violet
• B. Methyl orange
• C. Iodine solution
• D. Alcohol (decolorizing agent)
• E. Safranin

Hint:

Remember: The Gram stain procedure involves crystal violet, iodine, alcohol, and safranin to differentiate bacterial types.

Answer 1

The Correct Option is A

Step 1: Understanding Gram staining process.
In Gram staining, bacteria are subjected to a series of staining reagents that help classify them as either Gram-positive or Gram-negative.
- Crystal violet is used as the primary stain, which initially stains all bacteria.
- Iodine solution is used as a mordant to fix the crystal violet stain in the cell.
- Alcohol is then used to decolorize the smear, allowing differentiation between Gram-positive and Gram-negative bacteria.
- Safranin is used as a counterstain to color Gram-negative bacteria pink, as they lose the initial crystal violet stain.
Step 2: Conclusion.
Therefore, the correct staining reagents used in the Gram staining process are (A) Crystal violet, (B) Methyl orange, (C) Iodine solution, and (D) Alcohol.