Electrophoretic separation of biopolymers in a matrix of polyacrylamide covalently linked to agarose

A new type of agarose polyacrylamide mixed-bed gel, obtained by simultaneous gelation of a novel type of allyl-activated agarose and its copolymerization with acrylamide, has pore sizes intermediate between those of polyacrylamide and agarose. The process used to activate the agarose chains enables the substitution to be controlled. As indicated by nuclear magnetic resonance (NMR), only one allyl group was inserted per agarose basic unit. Several formulations of mixed-bed gels, containing different percentages of acrylamide, were compared with conventional polyacrylamide or agarose gels. Resolution, migration distance and band sharpness of different molecular mass fragments were evaluated, with two types of gel run side-by-side in a vertical or horizontal system. The faster electrophoretic mobility of DNA in dilute mix-bed gels and the improved separation of the component of high molecular mass (1 to 6 kbp) of the 1 kbp ladder indicate that these matrices have larger porosity than any dilute polyacrylamide formulations. Sodium dodecyl sulfate (SDS)-protein complexes migrate in the mixed gels faster than in polyacrylamide gels of the same %T.