Size separation of sodium dodecyl sulfate–proteins by capillary electrophoresis in dilute and ultra‐dilute dextran solutions

Abstract

SDS capillary gel electrophoresis is a widely used in the biopharma and the biomedical fields for rapid size separation of proteins. However, very limited information is available on the use of dilute and ultra‐dilute sieving matrices for SDS–protein analysis. Here, background electrolytes (BGEs) containing 1%–0% dextran were used in borate‐based BGE to separate a protein sizing ladder (PSL) ≤225 kDa and the intact and subunit forms of a therapeutic monoclonal antibody (mAb). The separation performance for the PSL and mAb components differed significantly with decreasing dextran concentration. Ferguson and reptation plots were used to elucidate the separation mechanism. Highly diluted dextran solutions resulted in linear Ferguson plots for both solute types (cf. Ogston theory) in spite of this model assumes a rigid pore structure, thus cannot describe the separation mechanism in ultra‐dilute polymer solutions with no reticulations. The saddle differences between the resolution of the PSL and the intact/subunit mAb forms in ultra‐dilute dextran‐borate matrices suggested the importance of shape selectivity, manifested by the adequate separation of the SDS covered intact as well as light and heavy chain subunits of the therapeutic mAb even at zero dextran concentration.

CoMnOx Nanoflower-Based Smartphone Sensing Platform and Virtual Reality Display for Colorimetric Detection of Ziram and Cu2+

“…With the increase of living standards, pesticide residue in food has become a hot issue in society, and research on pesticide residue detection has become popular. Currently, common methods for the determination of pesticide residues include high-performance liquid chromatography (HPLC) [1], spectrophotometry [2], capillary electrophoresis [3], and voltammetry [4]. However, all of the above methods are not suitable for in-field analysis, severely constraining the widespread use of the above techniques for detecting pesticide residues on site and in a timely manner.…”