Liquid Chromatography Tandem Mass Spectrometry for the Measurement of Global DNA Methylation and Hydroxymethylation

Abstract

DNA methylation is an important epigenetic phenomenon. Global DNA methylation levels in the genome are tissue-specific and are reduced in the context of specific developmental and pathological states. Hence accurate assays to quantify global DNA methylation are required. In this review we describe different methods for global DNA methylation measurement and explain the methodology, strengths and limitations of the gold standard assay liquid chromatography tandem mass spectrometry (LC-MS/MS) for 5-methylcytosine and 5-hydroxymethylcytosine quantitation. Measurement of global DNA methylation using LC-MS/MS has helped to elucidate the effects of environmental exposures and demethylating drugs that can alter DNA methylation levels and further studies using this technique may provide insights on the prevention and/or reversal of DNA hypomethylation.