Brief report: electrophoretic separation of oligonucleotides in replenishable polyacrylamide-filled capillaries

Linear polyacrylamide at concentrations of 8 to 10% seems to be an excellent matrix for the electrophoretic separation of oligonucleotides and DNA sequencing reactions. However, these solutions, as they are normally prepared, have an enormous viscosity and the polymerization must be done within the capillary. Based on theoretical considerations, we found that linear polyacrylamide of moderate molecular weight and therefore low viscosity could be used instead. We show that the separation of oligonucleotides obtained with such solutions is comparable to those obtained with in situ polymerization of linear or crosslinked polyacrylamide. This method allows easy refilling of the capillaries and might be a step towards automation of oligonucleotide analysis and DNA sequencing.