Sequence Specific Separation of Target DNA in Micellar Electrokinetic Chromatography

摘要

We present the use of hydrophobically labeled peptide nucleic acid (PNA) probes for the multiplexed detection and separation of oligomeric DNA in micellar electrokinetic chromatography (MEKC). MEKC is an operational mode of capillary electrophoresis in which a surfactant is added to the running buffer at a concentration above its critical micelle concentration. In addition to differences in electrophoretic mobilities, separation of compounds can be achieved through differences in the partitioning of a molecule into the micellar core of the migrating surfactant assemblies. Due to the nearly constant charge-to-mass ratio of DNA targets, the electrophoretic mobility of DNA is largely insensitive to its length and sequence. In addition, the negatively charged backbone of DNA renders it sufficiently hydrophilic, limiting interaction with the surfactant assemblies. Interaction with the micellar subphase has been promoted through the use of a PNA probe appended to an aliphatic tail, forming a peptide nucleic acid amphiphile (PNAA).