Question

1. Why is the Acid-fast stain of diagnostic importance?
2. Why is steaming required in the Acid-fast stain?
3. What is the primary stain in the Acid-fast stain?
4. At the end of the Acid-fast stain what is the color of an acid-fast organism? ____________; and a nonacid-fast organism? ______________________

Answer 1

Ans :-1) Acid fast stain is differential stain used to identify acid fast organisms such as member of genus mycobscterium. It help to determine if a sample of blood, tissues, or other body substance is infected with bacteria that causes tuberculosis and other illness.

Ans :-2) The primary stain used in acid fast staining is carbolfuchsin, is a lipid soluble and contains phenol which helps the stain to penetrate the cell wall.

Steam helps to loosen up the waxy layer and promotes the entry of the primary stain inside the wall.

Ans -3) The primary stain used in acid fast staining is cabolfuchsin. The waxy acid fast cells retain the cabolfuchsin even after a decolorizing agent is applied.

Ans :-) Acid fast scells stains red while other cells stain blue (when methylene blue is used as counterstain) .