DNA methylation profiling using bisulfite-based epityping of pooled genomic DNA.

DNA methylation plays a vital role in normal cellular function, with aberrant methylation signatures being implicated in a growing number of human pathologies and complex human traits. Methods based on the modification of genomic DNA with sodium bisulfite are considered the 'gold-standard' for DNA methylation profiling on genomic DNA; however they require large amounts of DNA and may be prohibitively expensive when used on the large sample sizes necessary to detect small effects. DNA pooling approaches are already widely used in large-scale studies of DNA sequence and gene expression. In this paper, we describe the application of this economical DNA pooling technique to the study of DNA methylation profiles. This method generates accurate quantitative assessments of group DNA methylation averages, reducing the time, cost and amount of DNA starting material required for large-scale epigenetic investigation of disease phenotypes.