A flexible, high-throughput DNA methylation profiling technology has been introduced that is capable of surveying up to 1,536 methylation sites across 96 samples simultaneously. Illumina Inc. pairs their BeadArray platform with their GoldenGate assay to perform genome-wide methylation profiling across multiple areas such as cancer and human embryonic stem cell research. The GoldenGate Methylation Cancer Panel I, the first standard panel, covers 1,505 methylation sites over 800 cancer genes. Custom-content methylation panels will soon be available. Methylation is a form of epigenetic modification that does not affect the primary structure of the genetic code, but rather affects secondary interactions that play a critical role in the regulation of gene expression. Since aberrant DNA methylation is known to be associated with a variety of human diseases including cancer, diabetes, and certain neurological disorders, methylation patterns can help identify and validate biomarkers or support clinical diagnostics. Quantitative methylation measurement at the single CpG site level offers high resolution. CpG sites are regions of DNA where a cytosine nucleotide is located adjacent to a guanine nucleotide, the nucleotides linked together by a phosphate. The attachment of a methyl group (termed methylation) to the cytosine nucleotide at the CpG site occurs throughout genes; abnormal methylation of these CpG sites has been shown to affect expression levels, which ultimately can play a significant role in the development and progression of diseases.