Non-cross-linked polyacrylamide

Widhalm, A., Schwer, C., Blaas, D., Kenndler, E. (1991). Capillary zone electrophoresis with a linear, non-cross-linked polyacrylamide gel separation of proteins according to molecular mass. J. Chromatogr. 549, 446 451. 

Figure 8 Illustration of whole-column imaging miniaturized capillary isoelectric focusing instruments with a LED as light source. A 1.2-cm capillary is used as a separation column for focusing. The outside polyimide coating of the capillary is removed, and the inside surface of capillary is coated with non-cross-linked polyacrylamide to eliminate electroosmotic flow. The two ends of the capillary are connected with inlet and outlet capillaries (with the same i.d. and o.d. as the separation capillary) by two pieces of porous hollow fiber. Two glass tubes are used as electrolyte tanks and glued directly on the glass slide by epoxy glue. The two pieces of hollow fiber are in the electrolyte tanks. The length of the capillary between the two electrolyte tanks is about 0.9 mm.

In the first report of Heiger et al non-cross-linked polyacrylamide was introduced into coated capillary columns and applied to the separation of double-stranded DNA fragments ranging up to several thousand base pairs [41] (Figure... 

An alternative to cross-linked polymer gels is non-cross-linked polyacrylamide. The non-cross-linked polymers separate by means of a mechanism... 

Wu D, Regnier FE (1992) Sodium dodecyl sulfate-capillary gel electrophoresis of proteins using non-cross-linked polyacrylamide. J Chromatogr 608349-356. 

Another possibility is to use a capillary gel electrophoretic method that is nowadays a routinely and commercially available method for the determination of the molecular mass of proteins/polypeptides. This method can also be used for the separation of collagen chains and their polymers. For example, this procedure is described in the literamre for the separation of collagen type I a-chains and chain polymers p (dimers), and y (trimers), and also chain polymers of related molecular mass 300,(X)0 and higher (typically in the study of the formation of crosslinks). Besides commercially available kits, another option is to use fused-silica or poly vinylalcohol-coated capillaries filled with non-cross-linked polyacrylamide or hydroxyl-propylmethylcellulose in a 50 vaM Tris-glycine buffer (pH 8.8) or phosphate buffer (50 vaM, pH 2.5) (Table 1). 

Non-cross-linked polyacrylamide 50 mM Tris-glycine buffer, pH 8.8... 

Capillary SDS-gel electrophoresis is a rapid automated separation and characterization technique for protein molecules and is contemplated as a modern instrumental approach to sodium dodecylsulfate-polyacrylamide slab-gel electrophoresis (SDS-PAGE). Size separation of SDS-protein complexes can be readily attained in coated capillaries filled with cross-linked gels or non-cross-linked polymer networks. Figure 9 depicts one of the early applications of the technique for the analysis of a standard protein test mixture ranging in size from 14.2 to 205 kDa. 

Gels used for the stationary phase can be hydrophilic, for separations in aqueous and other polar solvents, or hydrophobic, for use in non-polar or weakly-polar solvents. Agar, starch, polyacrylamide and cross-linked dextrans possess hydroxyl or amide groups and are thus hydrophilic. They swell... 

Swell the dry beads made of cross-linked dextran, polyacrylamide or gelatin in PBS-A or Hepes buffered saline as described by the manufacturer. The cross-linked dextran beads require 2-3 h to swell at room temperature. Avoid stirring with a simple bar magnet as this may grind the beads. Addition of non-ionic detergent (e.g. Tween 80) to 0.1% may help initial wetting of the microcarrier. 

Gels used for the stationary phase can be hydrophilic, for separations in aqueous and other polar solvents, or hydrophobic, for use in non-polar or weakly-polar solvents. Agar, starch, polyacrylamide and cross-linked dextrans possess hydroxyl or amide groups and are thus hydrophilic. They swell in aqueous media and in such solvents as ethylene glycol and dimethylform-amide. Bio-Cel (a co-polymer of acrylamide and jV.W -methylene-bisacryl-amide) and Sephadex (dextran cross-linked with epichlorhydrin) arc two commercially available gels made in bead form. Cross-linking produces a... 

---