a bed of transparent , water insoluble , charge - free crosslinked gel which is suitable for use in electrophoresis is prepared . the gel is formed by dissolving a linear polysaccharide , such as agarose , in a suitable solvent , such as water . this dissolution may be accomplished with agitation . a suitable cross linking agent , which is not itself charged , nor does it become charged upon contact with water , at a ph of 2 to 12 , is then added to the solution , possibly with agitation in order to get thorough mixing of the linear polysaccharide and the cross linking agent . this mixture is then allowed to incubate and react in a quiescent state to substantially simultaneously gel and crosslink to form the desired cross linked gel bed . preferred cross - linking agents are bis - epoxides , halo - epoxides , bis - haloalkanes , bis - halo - alcohols , alkanediol - bis - alkyl sulfonates , alkanediol - bis - aryl sulfonates or divinylsulfone . the liner polysaccharide maybe mixed with a synthetic polymer such as polyvinyl alcohol .