Capillary electrophoresis of proteins in bare fused-silica capillaries

Capillary electrophoresis of proteins and peptides is generally problematic, due to nonspecific interactions between proteins and silanol groups on the capillary surface exposed to the electrolyte. This interaction can cause peak broadening and asymmetry, non-reproducible migration times, low mass recovery, and irreversible adsorption. This article briefly overviews the most common strategies used to solve these problems and describes the effectiveness of several reagents (monovalent and poly-valent amines) added to the background electrolyte to prevent proteins interacting with the capillary wall. The action of these additives and other operative parameters on electroosmotic flow and electrophoretic mobility of solutes is discussed.