Electrophoresis on uncrosslinked polyacrylamide: Molecular sieving and its potential applications

Abstract

Uncrosslinked polyacrylamide, a viscous liquid, provides a molecular sieving effect in electrophoresis qualitatively the same as that of crosslinked gels. This finding confirms previous results by others using uncrosslinked polyacrylamide mixed with various gel matrices. It provides a sieving medium constituted by an entirely and necessarily random association of inert fibers, as stipulated for interpretation of migration by the Ogston theory. Ferguson plots of several proteins in uncrosslinked polyacrylamide exhibit Yo values smaller and less divergent from one another than in 5 % crosslinked gels, suggesting a curvature of the Ferguson plots of crosslinked polyacrylamide gels at low %T. If linearity of these plots at low %T, 0 %C could be demonstrated, a means would be found to determine accurate values of free mobility by their linear extrapolation to 0 gel concentration. Potentially, uncrosslinked polyacrylamide at low concentrations may provide a tool for the analytical sieving of subcellular particles. However, electrophoresis in uncrosslinked polyacrylamide at concentrations of less than 10 %is perturbed by convection, and thus these potential applications will depend on combining it with a suitable anticonvective device.

On the separation mechanism of capillary sodium dodecyl sulfate‐gel electrophoresis of proteins

“…The results in this paper clearly show t4at in PEO-mediated capillary electrophoresis of SDS-protein complexes, increasing the concentration of the same chain length polymer solution or increasing the chain length of similar concentration, or both, increases the sieving capability of the polymer solution. Tietz and Chrambach [43] suggested that the average apparent chain length of a crosslinked polymer is always longer than the similar molecular mass non-crosslinked polymer. Therefore, some crosslinking (either chemical or dynamic) should increase the separation capability of a given polymer network.…”

DNA analysis on electrophoretic microchips: Effect of operational variables

“…Most of the important operational variables in gel electrophoresis based analysis of DNA fragments, such as sieving matrix concentration, applied electric field strength, separation temperature, etc., have been well characterized in conventional slab-gel electrophoresis [16,17], capillary gel electrophoresis (CGE) [18,19] and ultrathinlayer gel electrophoresis (UTLGE) [20,21]. Yet, the migration properties of dsDNA molecules are somewhat different in these various separation formats.…”

Rapid single nucleotide polymorphism analysis by primer extension and capillary electrophoresis using polyvinyl pyrrolidone matrix

“…Linear polymers, such as noncross-linked polyacrylamide [2], derivatized celluloses [3], polyethylene oxides [4] and polyvinylpyrrolidone (PVP) [5] have all been demonstrated to be effective in electric field mediated size separation of DNA molecules. Although, the advantages of these noncross-linked polymers have been demonstrated almost entirely in capillary electrophoresis applications [6], it had been shown that very high concentration linear polymers can also be used in planar separation format [7,8]. This lower viscosity noncross-linked polymers are easily replaced within capillary columns [9] supporting repetitive work with these matrices.…”