A new separation medium for DNA capillary electrophoresis: self-assembly behavior of Pluronic polyol E 99P 69E 99 in 1X TBE buffer

Abstract

The unique sol–gel transition property of E 99P 69E 99 (with E and P being poly(ethylene oxide) and poly(propylene oxide), respectively), a Pluronic polyol F127, could become a useful separation medium in the miniaturization and automation of capillary electrophoresis (CE). Static light scattering (SLS), dynamic light scattering (DLS), and small-angle X-ray scattering were used to study the solution property and the gel-like structures of F127 in a CE buffer (1X TBE) for DNA separation. F127 in the CE forms core-shell micelles with a closed-association process. The critical micelle concentration (cmc) decreases and the micellar association number increases with increasing temperature. At larger solution concentrations, small-angle X-ray scattering results showed that the gel-like structure formed by close packing of the micelles had a face centered cubic (fcc) lattice. In the gel-like region the association number and also the micellar size were not affected by concentration changes. With F127 solution as a separation medium, CE could be performed successfully with a detection length of only 4 cm for separation of double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) fragments.