Affinity capillary electrophoresis of DNA for detection of single-nucleotide polymorphisms and point mutations. Comprehensive study for optimization of the weak affinity.

A single-stranded DNA and its point mutant can be separated with affinity capillary electrophoresis (ACE) in which an appropriate ligand DNA is used as a pseudo-stationary affinity phase. In this paper, we systematically examine the effects of ligand sequence, capillary temperature, and cation concentration on the ACE separation quality, which is quantitatively evaluated in terms of resolution and peak height. For fine tuning of the affinity, control of MgCl(2) concentration and insertion of a spacer sequence into the ligand DNA are more effective than control of the capillary temperature.