Preparative capillary zone electrophoresis using a dynamic coated wide-bore capillary

From micro to macro: conversion of capillary electrophoretic separations of biomolecules and bioparticles to preparative free-flow electrophoresis scale

This invited contribution in the special issue of Electrophoresis published in celebration of the 30th Anniversary of this journal reflects the impact of our milestone paper [Prusík, Z., Kasicka, V., Mudra, P., Stepánek, J., Smékal, O., Hlavácek, J., Electrophoresis 1990, 11, 932-936] in the area of conversion of microscale analytical and micropreparative CE separations of biomolecules and bioparticles into (macro)preparative free-flow electrophoresis (FFE) scale on the basis of a correlation between CE and FFE methods. In addition to the survey of advances in the relatively narrow field of CE-FFE correlation and CE-FFE conversion, a comprehensive review of the recent developments of micropreparative CE and (macro)preparative FFE techniques is also presented and applications of these techniques to micro- and (macro)preparative separations and purifications of biomolecules and bioparticles are demonstrated. The review covers the period since the year of publication of the above paper, i.e. ca. the last 20 years.

Off-line coupling of preparative capillary zone electrophoresis with microwave-assisted acid hydrolysis and matrix-assisted laser desorption ionization mass spectrometry for protein sequencing

An off-line coupling of capillary electrophoresis (CE) with microwave-assisted acid hydrolysis/matrix-assisted laser desorption ionization mass spectrometry (MAAH/MALDI) has been developed for protein identification and characterization. Preparative scale protein separations enable collection of 10-50 pmol of purified cytochrome c for subsequent sequencing using MAAH/MALDI. To reduce protein adsorption onto the silica surface, the cationic surfactant-based coatings, dimethylditetradecylammonium bromide and dimethyldioctadecylammonium bromide, are employed. The choice of the buffer conditions is critical for both the preparative CE and MAAH/MALDI method. The use of high buffer concentrations (100 mM Bis-tris) reduces electromigration dispersion, but suppressed MALDI ionization such that a peptide sequence coverage of only 80% was achieved at a sample loading of 40 g L(-1) of each cytochrome c. By reducing the buffer concentration to 25 mM Bis-tris, the sequence coverage increased to 95% at a sample loading of 40 g L(-1).