Enrichment of DNA hypomethylated regions using 5-methylcytosine glycosylase
Here we describe DEMETER-assisted 5-Methylcytosine Nicking sequencing (DMN-seq) to enrich DNA hypomethylated regions using 5mC-specific glycosylase, DEMETER, that nicks at 5mC sites to deplete hypermethylated regions. As the nick sites represent single-base 5mC, DMN-seq robustly resolves 5mC at single-base level preferentially at hypomethylated regions in colorectal cancer. When applied to cell-free DNA as low as 0.1 ng, DMN-seq significantly expands the scope of cancer biomarkers by capturing hypomethylated regions, with high sensitivity and reproducibility even in low-input clinical samples.