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Systematic evaluation of genome-wide methylated DNA enrichment using a CpG island array

Liu Yang23, Kunlin Zhang1, Wei Dai2, Ximiao He1, Qian Zhao1, Jing Wang1* and Zhong Sheng Sun2*

Author Affiliations

1 Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 100101 Beijing, PR China

2 Behavioral Genetics Center, Institute of Psychology, Chinese Academy of Sciences, 100101 Beijing, PR China

3 Zhejiang University School of Medicine, 310058 Hangzhou, PR China

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BMC Genomics 2011, 12:10  doi:10.1186/1471-2164-12-10

Published: 6 January 2011



Recent progress in high-throughput technologies has greatly contributed to the development of DNA methylation profiling. Although there are several reports that describe methylome detection of whole genome bisulfite sequencing, the high cost and heavy demand on bioinformatics analysis prevents its extensive application. Thus, current strategies for the study of mammalian DNA methylomes is still based primarily on genome-wide methylated DNA enrichment combined with DNA microarray detection or sequencing. Methylated DNA enrichment is a key step in a microarray based genome-wide methylation profiling study, and even for future high-throughput sequencing based methylome analysis.


In order to evaluate the sensitivity and accuracy of methylated DNA enrichment, we investigated and optimized a number of important parameters to improve the performance of several enrichment assays, including differential methylation hybridization (DMH), microarray-based methylation assessment of single samples (MMASS), and methylated DNA immunoprecipitation (MeDIP). With advantages and disadvantages unique to each approach, we found that assays based on methylation-sensitive enzyme digestion and those based on immunoprecipitation detected different methylated DNA fragments, indicating that they are complementary in their relative ability to detect methylation differences.


Our study provides the first comprehensive evaluation for widely used methodologies for methylated DNA enrichment, and could be helpful for developing a cost effective approach for DNA methylation profiling.