Capillary gel electrophoresis of oligonucleotides using polymer solutions

Capillary gel electrophoresis (CGE) has been recognized as an effective met hod for the analysis of oligonucleotides. CGE using polymer solutions is es pecially useful and effective compared with that using crosslinked gels, be cause of easy change of media. Replacement of media leads to the reproducib le separation of analytes. We have investigated CGE analysis of oligonucleo tides of less than 20 bases employing various kinds of polymers. Polyacryla mide, dextrin, dextran, pullulan, and poly(ethylene glycol) were used as si eving matrixes at concentrations of 0-30 %. Polydeoxythymidylic acids [p(dT )(11-20)] were used as a test sample. These small oligonucleotides were suc cessfully resolved on the basis of their base number by CGE using some of t hese polymer solutions. In particular, dextran was found to be effective an d baseline separation was observed when a 30 % dextran solution was employe d. Some validations such as linearity and reproducibility were also establi shed and this method was found to be an adequate quality control method for small oligonucleotides. Finally, CGE using a 30 % dextran solution was suc cessfully applied to impurity profiling of some synthetic oligonucleotides.