Fundamentals of Capillary Electrophoretic Migration and Separation of SDS Proteins in Borate Cross-Linked Dextran Gels

Recent progress in the development and production of new, innovative protein therapeutics require rapid adjustable high-resolution bioseparation techniques. Sodium dodecyl sulfate capillary gel electrophoresis (SDS-CGE) using a borate (B) cross-linked dextran (D) separation matrix is widely employed today for consistency analysis therapeutic proteins manufacturing release testing. Transient cross-linking semirigid polymer chains leads to SDS–protein complexes. To understand migration basis D/B gel, present work explores various formulations monomer (2, 5, 7.5, 10%) cross-linker (2 4%) concentrations. Ferguson plots were analyzed mixture standards with molecular weights ranging from 20 225 kDa, resulting nonlinear concave curves pointed nonclassical sieving behavior. While 2% D/4% B resulted fastest time, 10% D/2% was found produce greatest window, even higher than due significant increase electroosmotic flow former composition direction opposite complex migration. The study then focused on SDS-CGE monoclonal antibody its subunits. A combination weight shape selectivity as well as, lesser extent, surface charge density differences (due glycosylation heavy chain) influenced Greater occurred concentration gels, while improved glycoselectivity obtained more dilute low B. This latter took advantage dextran–borate–glycoprotein complexation. revealed that by modulating (monomer) (cross-linker) ratios matrix, one can optimize specific biopharmaceutical modalities excellent column-to-column, run-to-run, gel-to-gel time reproducibilities (<0.96% relative standard deviation (RSD)). used dextran/4% represents good screening option, which be followed modified composition, optimized necessary.