Electrophoresis

This technique is useful for the separation of small charged molecules such as amino acids and small proteins. A strip of filter paper is moistened with buffer and the ends of the strip are immersed into buffer reservoirs containing the electrodes. The samples are spotted in the center of the paper, high voltage is applied, and the spots migrate according to their charges. After electrophoresis, the separated components can be detected by a variety of staining techniques, depending upon their chemical identity.

Electrophoretic techniques have also been adapted to other applications such as the determination of protein isoelectric points. Affinity gels with biospecific properties are used to study binding sites and surface features of proteins. Continuous flow electrophoresis is applied to separations in free solution and has found very useful application in blood cell separation. Recently, High Performance Capillary Electrophoresis (HPCE) has been developed for the separation of many classes of biological molecules.