Capillary Zone Electrophoresis Separations of Basic and Acidic Proteins Using Poly(vinyl alcohol) Coatings in Fused Silica Capillaries

Abstract

Poly(vinyl alcohols) (PVA) of a molecular weight of about 50 000 were applied to the modification of fused silica surfaces for the separation of large charged molecules such as proteins.Basic and acidic proteins could be separated in PVA-modified capillaries at highly optimized and analytically suitable performance with regard to efficiency, zone symmetry, and resolution. PVA can be used in the "dynamic" mode as an additive to the buffer medium or as a water-insoluble "permanent" coating on the fused silica surfaces which can be

Selectivity change in the separation of proteins and peptides by capillary electrophoresis using high-molecular-mass polyethyleneimine

“…The use of polymeric coatings has led to high efficiency and reproducible protein separations preventing the surface adsorptions. Polymers ranging from highly hydrophobic to highly hydrophilic were used for this purpose to obtain efficient separations of proteins in CE [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

Surface modification in microchip electrophoresis

“…Surfactants had also to be added to enable the analysis of proteins in PDMS-coated FS-capillaries. The observed separation efficiencies of about 40 000 plates are, however, only moderate compared to those obtained with hydrophilic coatings in classical CE [46]. Applied to MCE it was shown that for the fluorescein-labelled goat antihuman Fab fragment a sharp peak was observed.…”

“…Furthermore, a considerable suppression of analyte-wall interaction is often observed. For the suppression of protein adsorption and electroosmosis HPMC was found to be especially useful [46,47]. Accordingly, these cellulose derivatives are applicable for dynamic coating of microfluidic glass chips especially for DNA separation as they can suit as sieving buffer and for surface deactivation.…”

“…Coatings based on PVA, which has to be considered the most hydrophilic nonionic polymer, have proven to exhibit a particularly good performance in classical CE [46,77]. The use of covalently linked PVA coatings in microfluidic devices was mentioned by Zhang et al [74].…”

“…For this approach, which is based on a method introduced by Gilges et al [46] in classical CE, the microchannels were simply rinsed with a 1% solution of PVA followed by a drying step with N 2 and a heating step in a nitrogen flow. The coated devices exhibited a suppressed EOF and a considerable improved separation performance compared to uncoated chips.…”