What hemoglobin is the fastest of the normal hemoglobins?

Hemoglobin A (Hgb A) is recognized as the fastest among the normal hemoglobins due to its electrophoretic mobility. In standard laboratory tests such as hemoglobin electrophoresis, Hgb A migrates more quickly through the gel than other types of hemoglobin. This is largely attributable to its molecular structure and the fact that Hgb A is a β-globin chain variant, which allows it to pass through the gel matrix more efficiently.

Other forms of hemoglobin, such as Hgb F (fetal hemoglobin), Hgb C, and Hgb S, exhibit slower migration rates during electrophoresis due to differences in their charge and structure. Hgb F, for instance, has a greater affinity for oxygen and a different charge that slows its migration compared to Hgb A. Hgb C has a mutation that causes it to be less negatively charged, which also results in slower mobility. Similarly, Hgb S, which is linked to sickle cell disease, has significant structural changes that affect how it moves through an electrophoretic medium.

Understanding the unique properties of each hemoglobin type is crucial for correctly interpreting laboratory results and identifying hemoglobinopathies. This knowledge ensures accurate diagnoses and the appropriate management of blood disorders.