Which is the correct sequence of electrophoretic migration of hemoglobins from slowest to fastest on cellulose acetate at an alkaline pH?

Which is the correct sequence of electrophoretic migration of hemoglobins from slowest to fastest on cellulose acetate at an alkaline pH?

• A. C, S, F, A
• B. C, A, S, F
• C. C, S, A, F
• D. A, F, S, C

Answer: (C)

On alkaline cellulose acetate, separation relies mainly on net electric charge because the molecules are similar in size; the more negative the hemoglobin, the faster it migrates toward the positive electrode. Hb C has a beta chain mutation (glu to lysine) that reduces the molecule’s negative charge, so it moves the slowest. Hb S also decreases negative charge (glu to valine), but not as much as Hb C, so its mobility is a bit faster than Hb C. Hb A carries the normal negative charge, migrating faster than Hb S. Hb F, with gamma chains, tends to carry the greatest net negative charge among these, so it migrates the fastest. Thus the order from slowest to fastest is Hb C, then Hb S, then Hb A, then Hb F.

On alkaline cellulose acetate, separation relies mainly on net electric charge because the molecules are similar in size; the more negative the hemoglobin, the faster it migrates toward the positive electrode. Hb C has a beta chain mutation (glu to lysine) that reduces the molecule’s negative charge, so it moves the slowest. Hb S also decreases negative charge (glu to valine), but not as much as Hb C, so its mobility is a bit faster than Hb C. Hb A carries the normal negative charge, migrating faster than Hb S. Hb F, with gamma chains, tends to carry the greatest net negative charge among these, so it migrates the fastest. Thus the order from slowest to fastest is Hb C, then Hb S, then Hb A, then Hb F.