Peanut oil is used in the Ziehl-Neelsen acid-fast staining method.

• A. True
• B. False
• C. Only for Gram staining
• D. Not used in staining at all

Answer: (B)

Peanut oil is not used in the Ziehl-Neelsen acid-fast staining method. This stain relies on carbol fuchsin (a phenolic stain) applied with heat to penetrate the waxy walls of acid-fast bacteria, then decolorization with acid-alcohol, followed by a counterstain like methylene blue. Oil immersion may be used when viewing slides under the microscope to improve resolution, but that immersion oil is a specialized optical oil and not peanut oil, and it is not part of the staining reaction itself. Therefore, the statement is false because the staining protocol does not involve peanut oil.