CAPILLARY GEL-ELECTROPHORESIS AND THE ANALYSIS OF DNA PHOSPHOROTHIOATES

Capillary gel electrophoresis (CGE) is recognized as an effective meth od for the analysis of normal phosphodiester deoxyoligonucleotides (DN A). However, it was found that when the same electrophoretic principle s were applied to the analysis of phosphorothioate DNA, peak broadenin g due to the phosphorothioate moiety made CGE's utility questionable. Therefore, optimization of several parameters is necessary for CGE to be effective in leading to the precise and accurate analysis of phosph orothioate DNA. Phosphorothioates are oligonucleotide analogs acknowle dged as potential antisense therapeutics in the treatment of viral dis eases and certain cancers. In order to improve a CGE approach to the a nalysis of this class of therapeutics, several parameters were investi gated and improved upon. Three factors which proved critical in provid ing high resolution and good gel to gel reproducibility were: gel conc entration, buffer additives, and pH.