Capillary electrophoresis of proteins and peptides

Capillary electrophoresis (CE) is a high-resolution technique for the separation of a wide variety of molecules of biological interest such as metabolites, drugs, amino acids, nucleic acids, and carbohydrates. This unit focuses on the use of CE to separate proteins and peptides based on charge-to-mass ratios. Separation of proteins based on their isoelectric points is described along with a protocol for optimizing the separation conditions for a given protein. CE is also used for separations of peptides on an analytical scale and as a micropreparative technique--with either multiple separations that are pooled or a single, larger-scale separation--for the isolation of peptides from a protease digestion. In most of these examples the same capillary column can be used for all the separations. Only changes in buffer composition, ionic strength, and the presence or absence of additives are required for each specific application.