title: Enzymatic regional methylation assay for determination of CpG methylation density.
abstract: DNA methylation is a critical mechanism for epigenetic gene regulation. In mammalian cells, CpG methylation density often influences the transcription level of related genes. Here, we report a short and accurate method to determine the CpG methylation density of any DNA region by sequentially applying bisulfite PCR and SssI (CpG) methylase. We introduced simple and efficient binding and washing steps that greatly improve the previous methodology and considerably enhance the accuracy of the assay. The accuracy of this method allows the detection of differences at the level of a single CpG methylation site when homogeneous PCR product was used as substrate. We validated our method by bisulfite sequencing multiple clones of samples with variable levels of CpG methylation. We envision that for its accuracy, simplicity, low-cost, flexibility, minimum instrumentation requirements, and high-throughput potential our method could greatly benefit research on DNA methylation.
authors.affiliation: The Psychiatric Institute, Department of Psychiatry and Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
authors.forename: Zhijing
authors.initials: Z
authors.lastname: Zhang
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Chen
authors.forename: Hari
authors.initials: H
authors.lastname: Manev
mesh_terms: D001483:Base Sequence; D018899:CpG Islands; D019175:DNA Methylation; D017931:DNA Primers; D015257:DNA-Cytosine Methylases / Q000378:metabolism*; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; C081573:DNA modification methylase SssI; D015257:DNA-Cytosine Methylases