Hemoglobin electrophoresis is the movement of hemoglobin proteins in an electric field at a fixed pH. Because the various hemoglobins are comprised of different combinations of globin chains (normal or abnormal), they will demonstrate different degrees of mobility.
Typically, when a thalassemia or hemoglobinopathy is suspected, an alkaline hemoglobin electrophoresis is performed. For an alkaline electrophoresis, a hemolysate is applied to cellulose acetate, which is then electrophoresed in a buffer at pH 8.4-8.6. At this pH hemoglobin proteins move from cathode to anode. The proteins are visualized by the application of a dye, which also makes them measurable by densitometry.
The results of the alkaline electrophoresis can be confirmed with acid electrophoresis.