Isoelectric focusing

Adapted from Chapter 7, Gel Electrophoresis of Proteins, by David E. Garfin, Pages 197-268, in Essential Cell Biology, Volume 1: Cell Structure, A Practical Approach, Edited by John Davey and Mike Lord, Oxford University Press, Oxford UK (2003). Used by permission of Oxford University Press.

Isoelectric focusing is an electrophoretic method in which proteins are separated on the basis of their pIs (1-12). It makes use of the property of proteins that their net charges are determined by the pH of their local environments. Proteins carry positive, negative, or zero net electrical charge, depending on the pH of their surroundings.


Capillary Isoelectric Focusing

Gregory G. Wolken and Dr. Edgar A. Arriaga, University of Minnesota, Minneapolis, MN

What electrophoretic separation method can be used to separate different species of bacteria, fractionate subcellular components of a cell homogenate, test the purification of a virus from an environmental sample, and more? Isoelectric focusing (IEF) is a powerful technique for the analysis of biological particles such as cells, organelles, and viruses.1 This flexible technique can be used for separation and fractionation, functional measurements, and discernment of the chemical properties of biological particles. Capillary IEF is a technique that achieves high-resolution separations with very small amounts of sample and low limits of detection.