Which hemoglobin is the slowest of the normal hemoglobins during electrophoresis?

The slowest of the normal hemoglobins during electrophoresis is Hemoglobin A2 (Hgb A2). Electrophoresis separates proteins based on their size and charge, and various types of hemoglobin have different mobilities. Hgb A2 has a higher molecular weight and exhibits a slower migration compared to Hgb A, Hgb F, and Hgb S due to its unique structure and increased quantity of the alpha and delta chains.

Hgb A typically migrates faster than Hgb A2 because it consists of two alpha and two beta chains, allowing it to exhibit a more significant negative charge and smaller size that facilitates quicker movement through the gel during electrophoresis. Hgb F, or fetal hemoglobin, containing two alpha and two gamma chains, moves slower than Hgb A but faster than Hgb A2. Hgb S, associated with sickle cell disease, has altered migration patterns mainly due to its mutations causing a different charge than normal hemoglobin types, influencing its speed as well.

Therefore, Hgb A2 is indeed the slowest of the normal hemoglobins during electrophoresis, illustrating the importance of understanding the structural and charge differences among the various forms of hemoglobin.