Answer to Question #11129 in Biochemistry for Maria

Question

Explain the effect of increasing and decreasing the pH on the electrophoresis process

Answer 1

Electrophoresis is a method for separating substancesaccording to their charge. Proteins, nucleic acids and other biomolecules have different charged groups (such as -NH3[+], -PO4[2-], -SO3[-]) that led to a movement of biomolecules in the electric field. Changes in solution pH result in changes of charge of the biomolecules, because of this results of electrophoresis will be different in different pH. I.e. if we increase solution pH, -NH3+ groups loose their charge and turn to -NH2 groups, thus a molecule will decrease its charge and will move slower during electrophoresis. On the contrary -SO3 groups are uncharged in the low pH, but obtain negative charge in the high pH (thus molecule with large amount of -SO3 groups will move during electrophoresis only in solutions with high pH).