Handy and prompt DNA separation using PNA with internal disulfide bond.

PNA (peptide nucleic acid) is a DNA analogue which has a peptide backbone. PNA is very useful as a recognition probe because of its immensely high affinity to DNA. In this study, we used PNA as a DNA separation tool. Furthermore, we introduced a cleavable disulfide bond into main chain of PNA in order to facilitate the removal of PNA from PNA/DNA duplex. This disulfide bond was readily cleaved by various reducing agents and then the resultant two short PNA fragments could not form stable PNA/DNA duplex anymore. Accordingly, a desired DNA fragment was picked up from the DNA mixtures and readily recovered by the reductive treatment.