Detection of aberrant DNA methylation in acute myeloid leukemia samples compared to normal human monocytes

To globally define CG-rich regions that show altered DNA methylation im leukemia, we analyzed the methylation status of 23,000 CpG islands of the human genome in twenty seven acute leukemia samples as well as normal blood monocytes using our previously described methyl-CpG immunoprecipitation (MCIp) technique (Gebhard et al. 2006; Schilling and Rehli 2007). This method enriches for highly CpG methylated DNA that can be directly applied to fluorescent labeling and oligonucleotide microarray hybridization without an additional amplification step. CpG-methylated genomic DNA was enriched using methyl-CpG immunoprecipitation (MCIp). On each microarray, the enriched material from leukemia samples was compared to the enriched material from normal blood monocytes to identify aberrantly methylated regions. MCIp-on-Chip; comparative genomic hybridization