Which type of staining method involves the dye binding directly to the specimen, thereby imparting color to it?

• A. Direct (positive) staining
• B. Gram staining
• C. Negative staining
• D. Acid-fast staining

Answer: (A)

Verified step by step guidance

1. Understand the difference between direct (positive) staining and other staining methods. Direct staining involves the dye binding directly to the specimen, coloring the cells themselves.
2. Recall that in Gram staining, multiple dyes and steps are used to differentiate bacteria based on cell wall properties, not just direct dye binding.
3. Recognize that negative staining colors the background instead of the specimen, so the cells appear clear against a dark background.
4. Know that acid-fast staining is a differential stain used to identify acid-fast bacteria by their resistance to decolorization, involving multiple steps and dyes.
5. Conclude that the staining method where the dye binds directly to the specimen, imparting color to it, is called direct (positive) staining.