In the capsule stain using India ink, capsules are distinguished as __________ surrounding cells.

• A. clear halos
• B. darkly stained regions
• C. pink cytoplasmic areas
• D. blue granules

Answer: (A)

Verified step by step guidance

1. Understand the principle of the capsule stain using India ink: India ink is an acidic stain that stains the background but does not penetrate the capsule or the cell.
2. Recognize that the capsule itself is a non-ionic, gelatinous layer that does not take up the stain, so it remains unstained or clear.
3. Note that the bacterial cell inside the capsule can be stained by a different stain (such as crystal violet or safranin), making it visible against the dark background.
4. Therefore, in the final microscopic image, the capsule appears as a clear, unstained halo surrounding the stained bacterial cell against the darkly stained background.
5. Conclude that the correct description of capsules in the India ink stain is 'clear halos' surrounding cells.