A throat swab from a child with suspected diphtheria is stained with Albert stain. Which specific structure is demonstrated by the presence of dark blue-green metachromatic granules against a light green cytoplasm?
- A Volutin granules ✓
- B Lipid inclusions
- C Glycogen granules
- D Sulfur granules
Correct answer: A. Volutin granules
Explanation
Albert stain demonstrates volutin granules in Corynebacterium diphtheriae. These are dark blue-green metachromatic granules composed of polyphosphates, visible against a light green cytoplasm. Sulfur granules are seen in Actinomyces. Lipid and glycogen inclusions are not specifically demonstrated by Albert stain. Volutin granules are the key diagnostic feature.
Reference: Ananthanarayan and Panicker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.