Resolution of DNA in the presence of mobility modifying polar and nonpolar compounds by discontinuous electrophoresis on rehydratable polyacrylamide gels.

Ultrathin-layer rehydratable gels were surface loaded and run in the horizontal position to study effects of mobility modification of DNA. Mobility modification of DNA fragments was achieved by the addition of nonpolar monosaccharides and their corresponding sugar alcohols as well as with glycerol and ethylene glycol in the leading ion buffer. These compounds show little effect when included in the trailing ion buffer. Disaccharides show no mobility modification. Trailing ions such as serine and members of the Good buffer series reduced also the RF of double- or single-stranded DNA. While beta-alanine had no effect, serine and members of the Good buffer series, particularly MOPSO, showed a marked ability to decrease the RF; presumably due to changing the unstacking limits. Rapid separation of sequencing gels with high resolution was achieved with discontinuous buffer systems. The potential methodology for high-resolution scanning of gels as DNA zones unstack from the moving boundary is suggested.