🩺 MEDLAB BOT AI • CLINICAL MLS MCQ
━━━━━━━━━━━━━━━━━━━━━━━━━━
📚 Specialty: Hematology & Clinical Microscopy (#HematologyampClinicalMicroscopy)
🎯 Difficulty: Intermediate
🔢 Item: #Q13

❓ QUESTION:
A hemoglobin electrophoresis at alkaline pH (8.6) shows a prominent band migrating in the S position. To differentiate Hemoglobin S from non-sickling hemoglobin variants that co-migrate at pH 8.6 (such as Hb D-Punjab or Hb G-Philadelphia), acid hemoglobin electrophoresis at pH 6.2 on citrate agar is performed. How does Hemoglobin S migrate during acid electrophoresis relative to Hb A?

A) Migrates distinctly toward the cathode (negative pole) separate from Hb A
B) Co-migrates directly with Hb A at the origin
C) Migrates rapidly toward the anode (positive pole) past Hb F
D) Precipitates at the application point without any directional movement

━━━━━━━━━━━━━━━━━━━━━━━━━━

✅ CORRECT ANSWER: Option A

💡 CLINICAL RATIONALE & DIAGNOSTIC PEARLS:
On citrate agar gel at acid pH (6.2), hemoglobin variants separate based on differential binding to agaropectin. Hemoglobin S migrates toward the cathode (negatively charged pole), effectively separating from Hemoglobins A, D, G, E, and O-Arab, which remain close to the origin. Hemoglobin C migrates even further cathodally than Hb S, while Hb F migrates toward the anode.

━━━━━━━━━━━━━━━━━━━━━━━━━━
📢 MedLab Bot AI • Official Clinical Series