Hemoglobin electrophoresis

Abstract:
The different globin tetrameres (HbA=α₂β₂, HbF=α₂γ₂, HbA₂=α₂δ₂ etc.) of hemoglobin have different electrical charges. If electric current is applied, the globin chain pairs move at varying speeds according to their charges. Since the electrical charge changes with the pH, hemoglobin electrophoresis is performed both in an alkaline as well as in an acidic environment.

Assessment:
On account of the differing rate of migration of the globin chain pairs, specific band patterns are seen in gel or cellulose acetate electrophoresis.

Normal range:
HbA = 95 -98%, HbA₂ = 1.5 - 3.5%, HbF = 0.2 - 1.0 %

Typical patterns in normality and some hemoglobinopathies

Normal (or α-Thalassemia minor)
β-Thalassemia minor
β-Thalassemia major
Sickle cell anemia, heterozygous
Sickle cell anemia, homozygous
Sickle cell anemia / β-Thalassemia
HbH disease
Hemoglobin C disease
A2=HbA2, S=HbS, F=fetal Hb, A=HbA, H=HbH=β4

Indication:
Suspicion of hemoglobinopathy , especially of β-globin chains. For the diagnosis of α-Thalassemieas, molecular methods have to be applied.