Although newer detection methods exist, hemoglobin electrophoresis is considered the classic gold-standard in identifying the different types of hemoglobin.
Hemoglobin electrophoresis is the movement of hemoglobin proteins in an electric field at a fixed pH.
Since different types of hemoglobin molecules 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 electrophoresis is performed which may be confirmed with acid electrophoresis.
For an alkaline hemoglobin electrophoresis, a hemolysate is applied to cellulose acetate which is 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.
