DNA capillary electrophoresis using poly(vinyl alcohol). II. Separation media.

We represent the first extensive study on DNA capillary electrophoresis using various poly(vinyl alcohol) (PVAL)-related polymers as separation media. As a separation medium, PVAL homopolymer has shown poor resolutions probably due to its very strong hydrogen-bonding characteristics, resulting in extensive self-aggregation. On the other hand, poly(vinyl alcohol-co-vinyl acetate) and poly(vinyl alcohol-co-1-vinyl-2-pyrrolidone) (PVAL-VP), both with a degree of polymerization of approximately 3.0x10(3), have been found to give excellent electropherograms with good resolutions for the analysis of double-stranded (ds)DNA. PVAL-VP, with hydrolytic stability in high and low pH regions, has also yielded fair electropherograms for single-stranded (ss)DNA under neutral and alkaline conditions, although further investigation is essential in order to increase the resolutions necessary for DNA sequencing analysis. The separations obtained under alkaline conditions have shown significantly shorter retention times, one-third of that for the current commercial separation media, due to the higher ionization of phosphate groups in the DNA chains.