Non-covalent capillary coatings for protein separations in capillary electrophoresis

Adsorption of proteins, particularly basic proteins onto fused silica capillaries severely degrades capillary electrophoretic performance. This review provides a synopsis of the fundamentals underlying protein adsorption and its impact on CE performance. The efficacy of small molecule background electrolyte additives, surfactants, physically adsorbed polymers (dynamic and static), and successive multiple ionic-polymer layer coatings are evaluated using a number of performance metrics. Peak efficiency and migration time reproducibility are used as measures of reversible protein adsorption, while protein recovery, electroosmotic flow reproducibility and step changes in the baseline are used as indicators of irreversible protein adsorption.