MassARRAY EpiTYPER assay is a method for the quantative analysis of DNA methylation and identification of differentially methylated CpG sites in any genomic region or candidate gene. It combines base-specific enzymatic cleavage with MALDI-TOF mass spectromentry.
The bisulfite treatment converts non-methylated cytosine into uracil, thus generating methylation depending sequence changes in the genomic DNA template. PCR with T7-promotor tagged primers amplifies the template while preserving the induced sequences changes. After SAP treatment in vitro transcription and generated transcript undergoing the enzymatic base specific cleavage. The resulting fragments differ in size and mass depending on the sequence changes generated through bisulfite treatment. The fragment mass is determined by MALDI-TOF MS and the EpiTYPER software automatically generates a report that contains quantitative information for each analyzed fragment.