Question

Differential staining property of Gram staining is due to

• A. Difference in lipid content in Gram positive and negative bacteria
• B. Difference in protoplasmic contents in Gram positive and negative bacteria
• C. Difference in teichoic content in Gram positive and negative bacteria
• D. None of the above

Answer 1

The Correct Option is A

The Gram staining technique is based on differences in cell wall composition, specifically the lipid content, between Gram-positive and Gram-negative bacteria. 

Step 1: Understanding the Principle of Gram Staining - Gram-positive bacteria have a thick peptidoglycan layer with low lipid content, which retains the crystal violet stain, appearing purple. - Gram-negative bacteria have a thin peptidoglycan layer with high lipid content and an outer membrane. The alcohol decolorizer dissolves the lipid layer, allowing the stain to escape, making them take up the safranin counterstain and appear pink. 

Step 2: Evaluating the Options - Option (A) - Correct: The differential staining property is due to differences in lipid content between Gram-positive and Gram-negative bacteria. 
- Option (B) - Incorrect: The protoplasm does not directly affect Gram staining. 
- Option (C) - Incorrect: Teichoic acids are found in Gram-positive bacteria, but they do not determine staining properties. 
- Option (D) - Incorrect: Since lipid content influences Gram staining, this option is incorrect. 

Step 3: Conclusion Since lipid content in the bacterial cell wall determines the staining property, the correct answer is option (A).