A microbiologist wants to determine whether a bacterial sample contains mycobacteria. Which staining method should they use and why?

• A. They should use the acid-fast stain because it differentiates bacteria with mycolic acid in their cell walls.
• B. They should use a simple stain to quickly visualize all bacteria in the sample.
• C. They should use the Gram stain because it identifies the presence of lipopolysaccharides.
• D. They should use a capsule stain to highlight the protective layers around mycobacteria.

Answer: (A)