Methyl-DNA immunoprecipitation (MeDIP): hunting down the DNA methylome

One of the most challenging projects in the field of epigenetics is the generation of detailed functional maps of DNA methylation in different cell and tissue types in normal and disease-associated conditions. This information will help us not only understand the role of DNA methylation but also identify targets for therapeutic treatment. The completion of the various epigenome projects depends on the design of novel strategies to survey and generate detailed cartograms of the DNA methylome. Methyl-DNA immunoprecipitation (MeDIP) assays, in combination with hybridization on high-resolution microarrays or high-throughput sequencing (HTS) techniques, are excellent methods for identifying methylated CpG-rich sequences. We provide a critical overview of different genome-wide techniques for DNA methylation analysis and propose that MeDIP assays may constitute a key method for elucidating the hypermethylome of cancer cells.