When performing electrophoresis at pH 8.6, which hemoglobin molecule migrates the fastest on cellulose acetate toward the anode?

When performing electrophoresis at pH 8.6, which hemoglobin molecule migrates the fastest on cellulose acetate toward the anode?

• A. A1
• B. A2
• C. F
• D. S

Answer: (A)

At pH 8.6, hemoglobins carry a net negative charge and move toward the anode; the more negative the molecule, the faster it migrates. The adult hemoglobin A has the greatest negative net charge among the options, so it travels toward the anode the fastest on cellulose acetate. Hemoglobin S has one amino acid substitution (Glu to Val) that reduces negative charge, slowing its movement. Fetal hemoglobin and HbA2 have less negative charge at this pH, so their migration is slower. Therefore, the fastest migrating hemoglobin is adult HbA.

At pH 8.6, hemoglobins carry a net negative charge and move toward the anode; the more negative the molecule, the faster it migrates. The adult hemoglobin A has the greatest negative net charge among the options, so it travels toward the anode the fastest on cellulose acetate. Hemoglobin S has one amino acid substitution (Glu to Val) that reduces negative charge, slowing its movement. Fetal hemoglobin and HbA2 have less negative charge at this pH, so their migration is slower. Therefore, the fastest migrating hemoglobin is adult HbA.