G6PD deficiency is an X-linked disorder most common in individuals from malaria-endemic regions. Oxidative haemolysis is triggered by oxidative stress and visualised on peripheral smear as cells with displaced haemoglobin (Heinz bodies). The standard stain for detecting Heinz bodies is:

• A Prussian blue iron stain on bone marrow aspirate
• B Periodic acid-Schiff (PAS) for glycogen in red cells
• C Crystal violet (brilliant cresyl violet) supravital stain on unfixed blood ✓
• D Romanowsky (Giemsa) stain on fixed peripheral blood smear

Explanation

Heinz bodies are denatured haemoglobin precipitates that adhere to the inner red cell membrane; they are NOT visible on standard Romanowsky-stained smears but are revealed by supravital staining with crystal violet (or new methylene blue, brilliant cresyl blue) on unfixed whole blood. Romanowsky stains show 'bite cells' where spleen has pitted Heinz bodies. Prussian blue stains iron (sideroblasts); PAS stains glycogen.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.