Antisense DNA oligonucleotides I: The use of ionspray tandem mass spectrometry for the sequence verification of methylphosphonate oligodeoxyribonucleotides

Abstract

The sequences of synthetically prepared methylphosphonate oligodeoxyribonucleotides have been verified using ionspray tandem mass spectrometry with sample introduction via flow injection. The technique involves the use of product-ion scans from multiply protonated (4+ and 5+) precursors. Among the ions detected are several series of fragments of different charge states that indicate the base sequence of the intact molecule. Oligomers as large as 18 bases have been successfully characterized.