Illumina Methylation Assay

The Illumina Methylation Assay using the Infinium I platform uses 'BeadChip' technology to generate a comprehensive genome-wide profiling of human DNA methylation. Similar to bisulfite sequencing and pyrosequencing, this method quantifies methylation levels at specific loci within the genome. This assay is used for methylation probes on the Illumina Infinium HumanMethylation27 BeadChip (henceforth, 27k [methylation] array). Probes on the 27k array target regions of the human genome to measure methylation levels at 27,578 CpG dinucleotides in 14,495 genes. The Infinium HumanMethylation450 BeadChip array targets >450,000 methylation sites.

DNA methylation plays a significant role in the epigenetic regulation of chromatin structure, which in the last decade has been recognized to be important in the regulation of gene expression, development and genetic imprinting in vertebrates. Changes in the methylation pattern and level have been shown to contribute to cancer and various developmental diseases. For example, hypermethylation at the promoter CpG islands of a tumour suppressor gene, which in turn leads to its silencing, is frequently associated with tumourgenesis. A large scale measurement of DNA methylation patterns from a wide selection of genes may enable us to understand better the relationships between epigenetic changes and the genesis of different diseases and a better understanding of the role that epigenetics plays in tissue specific differentiation.

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