ABSTRACT
Denaturants, such a urea, formamide, etc. are usually used in ss DNA separations, in DNA sequencing gels and in some instances for ds DNA separations. Agarose, which is very popular in conventional slab gel separations of large DNA fragments, can also be filled into capillaries and used as separation media. Polythylene oxide was successfully applied to DNA separations, particularly to DNA sequencing. Preinjection of a low-viscosity buffer plug helped to obtain high-efficiency separation with sharp peaks from high-salt-containing PCR products. Capillary electrophoresis of these relatively short oligonucleotides using crosslinked or linear PA gel filled capillaries under denaturing conditions gives single-base resolution of phosphodiester antisense from its failure sequences, but rather unsatisfactory results with backbone-modified antisense DNA. CE separations have been demonstrated on ds DNA from 60 to 20,000 bp in size using both physical and chemical gel systems, with the bulk of this work performed on physical gels due to their convenience and superior column lifetimes.
