The gel you want may depend upon the separation you are attempting. Andras Guttman had a series of articles where he looked at how different gels (biopolymers) affected separations in CE. See "Gel and Polymer-Solution Mediated Separation of Biopolymers by Capillary Electrophoresis" A Guttman, J Chromatogr Sci, Oct 2003; 41: 449 - 459 OR "Rapid separation and purification of oligonucleotides by high-performance capillary gel electrophoresis" A S Cohen et al.,NAS, Dec 1988; 85: 9660 - 9663.

I believe that the best polymer for DNA separations is poly dimethylacrylamide.

I am assuming you are trying to separate DNA via CE.

In recent years, the work of Annelise Barron at Stanford has shown the efficiency of mixed pDMA (polydimethylacrylamide) and linear polyacrylamide. But the synthesis of these methylated acrylamide may be tedious.

I personally chose to use a mixture of hydroxyethylcellulose (HEC) and polyvinylpyrollidone (PVP) since 2009, after collaborating with Bruce McCord at Florida Internatioanl - who developed the system. The solutions can simply be prepared from commercial powders obtained from Sigma (HEC: 250 kDa | PVP: 1 MDa) while adjusting the proportions and completing with urea and, for instance, TAPS buffer.

For more information, download my 2012 and 2010 papers in Electrophoresis from my profile.  References for Bruce's initial work are contained therein.

Beckman Coulter offers a commercial replaceable gel kit for use in CGE. Here is some information about their product. The gel composition is proprietary, but the advantage of this kit is that it is commercially available. Several manufacturers of CE systems use this product and recommend it. Beckman also has their own lines of capillary systems.

http://sciex.myshopify.com/products/sdsmw-analysis-kit