Highly Charged Polyelectrolyte Coatings to Prevent Adsorption During Protein and Peptide Analysis in Capillary Electrophoresis

Capillary electrophoresis (CE) is an interesting technique for protein and peptide analysis. However, one of the major problemsconcerns sample adsorption on the internal capillary wall. The use of non-covalent coatings using highly charged polyelectrolytesis an efficient, simple, and fast approach to reduce peptide and protein adsorption phenomena. We have studied in a systematicmanner the effect of coating conditions on the stability and efficiency of multilayer coatings using poly(diallyldimethylammonium)chloride (PDADMAC) as polycation and polystyrene sulfonate (PSS) as polyanion. When optimal conditions defined in the protocolsare used, very stable coatings are obtained and adsorption phenomena are eliminated. The coatings are stable over a largerange of pH buffer (2–10) and in the presence of organic solvent. Hundreds of analyses can be performed without coating regeneration. Coated capillaries can be easily stored and reused.