Capillary Zone Electrophoretic Separation of Proteins Using Coated Capillaries

Abstract

The possibilities of capillary electrophoresis for the analysis of several basic and acid proteins by using different capillary modification procedures are shown. In order to reduce the interaction of proteins onto the capillary inner wall, potassium chloride (KCl), polyethyene glycol (PEG), poly(vinyl alcohol) (PVA), and hydroxyethylcellulose (HEC) were tested as additives in the running buffer. Furthermore, a PVA coated capillary was examined to compare the suitability of coating to separate different nature proteins (lysozyme, carbonic anhydrase, trypsin inhibitor, and bovine serum albumin) by capillary electrophoresis.The experiments were carried out at different concentrations of the additive, voltages and, in some cases, pH. This study showed that the PVA provides the better results, since both kinds of proteins could be analysed simultaneously without important adsorption drawbacks. When a poly(vinyl alcohol) coated capillary was used, the improved performance over bare fused-silica capillaries were emphasized. Efficiencies higher than 500,000 theoretical plates per meter were obtained.

Capillary electrophoresis‐based separation techniques for the analysis of proteins

“…Chemicals such as amines and surfactants have been tested with different degrees of success [76][77][78][79][80], including phospholipids 1,2-dilauroyl-sn-phosphatidylcholine [81,82] and didodecyldimethylammonium bromide [83]. Common polymers that are used to suppress protein adsorption and EOF include celluloses [84], dextran [85], PA [86,87], poly(vinyl alcohol) [88,89], PVP [90][91][92], and poly(ethylene oxide) (PEO) [93]. New dynamic coating materials such as EOTrol and UltraTrol have proved to be useful for the separation of protein isoforms by CZE [94].…”

The effect of sample salt additives on capillary electrophoresis analysis of intact proteins using surface modified capillaries

“…PVA coated capillaries have a hydrophilic and neutral surface, thus generating no EOF in CE analysis. These capillaries are commercially available and readily used for protein and peptide separation with CE [37,38]. Therefore, PVA coated capillaries were tested to investigate if the observed peak stacking effect could be obtained with a neutral surface.…”

Overview of the status and applications of capillary electrophoresis to the analysis of small molecules

“…These include reduction of undesired solute adsorption, elimination of EOF or reversal of the EOF direction. Separations of various basic and acidic proteins were performed [97] when polyethylene glycol (PEG), polyvinyl alcohol (PVA), and hydroxyethylcellulose (HEC) were employed as additives in the running buffer. Capillaries permanently coated with polyvinyl alcohol (PVA) where also compared and found to give the most efficient separations.…”

“…Separations on a multi-bore capillary using phosphate buffer or CElixir buffer (figure reproduced with permission from reference[97]). (a) Separation using phosphate buffer 50 mM phosphate 2.5, multi-bore capillary 19 m × 25 m channels, 27 cm long, 130 A, +5 kV, 30 • C, detection at 200 nm, sample salbutamol 1 mg/ml, 1 s injection.…”