Electrophoresis:

We know that positively charged ions (cations) move towards cathode and negatively charged ions (anions) move towards anode. Therefore, charged particles can move towards respective electrodes and the direction is decided according to their charge. The Electrophoresis is a separation method based on the migration of ions within an electric field.  It is one of the most significant techniques in analytical chemistry. The positively charged ions migrate towards a negative electrode and the negatively charged ions migrate towards the positive electrode. Ions have dissimilar rates of migration depending on their total charge, size, and shape and could, thus, be separated through this method. This separation technique was developed through Swedish chemist Arne Tiselius and he was awarded Nobel Prize within the year 1948 for his valuable contributions.

This versatile method is now-a-days applied to separate various species like drugs, inorganic ions, carbohydrates, amino acids, peptides, proteins, nucleic acids, etc. Actually, there have been innumerable applications of these methods within the biotechnological research and organization.

This unit deals along with principle, classification and instrumentation used in electrophoresis. Several analytical applications of these methods have also been highlighted.

In electrophoretic separation technique, a little amount of sample is permitted to flow by a paper or a semisolid gel media under a dc potential. These media could be porous and are immersed into an aqueous buffer solution. At a particular potential gradient, there is a differential movement of ions. The velocity of migration in the electric field is proportional to the charge-to-size ratio.

Objectives

After studying this Unit, you should be able to

• Elaborates electroosmotic flow,
• Define the basic principle of electrophoresis and operation, and
• Declare the classification of electrophoresis and the instrumentation used, and some typical applications