Electroendosmosis causes the gamma globulin band to migrate toward which electrode during electrophoresis?

• A. Cathode
• B. Anode
• C. Neutral
• D. No migration

Answer: (A)

Electroendosmosis is the bulk flow of the buffer inside a gel when an electric field is applied, caused by the negatively charged gel surface. This flow goes toward the cathode, dragging the solvent (and anything dissolved in it) along with it. In electrophoresis on standard gels, gamma globulins are carried by this electroosmotic flow toward the cathode, so their band appears migrating in that direction even if the proteins’ own charge would push them differently. So the gamma globulin band moves toward the cathode.