The Human Methylation 450K BeadChip enables the simultaneous quantitative monitoring of more than 480,000 CpG positions. This BeadChip has a 12-sample per array format and requiring only 500 ng of input. A positive methylated DNA control is added in each experiment. DNA methylation is measured using quantitative “genotyping” of bisulfite-converted genomic DNA. The analysis required the R software and several packages for data pre-processing and statistical analysis.