Methylated DNA is isolated from fragmented genomic DNA (5 ng–25 μg) by binding to the methyl-CpG binding domain of human MBD2 protein fused to the Fc tail of human IgG1 (MBD2-Fc), which is coupled to paramagnetic hydrophilic protein A beads (MBC2-Fc/Protein A Magnetic Bead). Two Fc domains can be bound to one site on protein A with high affinity (Kd=10-7). As the Fc fragment is a dimer, four MBD2 domains are exposed to the solvent per molecule of protein A, increasing the relative equilibrium constant 100-fold. This stable complex will selectively bind double-stranded methylated CpG containing DNA. After simple wash steps followed by magnetic capture, the enriched DNA sample is easily eluted in a small volume of nuclease-free water by incubation at 65°C. The sample is immediately ready for downstream analysis by a variety of methods including:
·Endpoint and real-time PCR assays.
·Bisulfite conversion followed by DNA amplification.
·Cloning and sequencing.
·Direct sequencing.
·Library preparation for high-throughput sequencing.
·Labeling for DNA microarray analysis.
·Methylation-sensitive restriction enzyme-based assays.
MBD-Fc and MCIp were originally developed by Michael Rehli at the University of Regensburg to improve the sensitivity and specificity of conventional CpG binding techniques.
Kit Components:
Each kit contains sufficient reagents for the enrichment of methylated DNA from up to 100 μg of fragmented input DNA. If starting with 5 ng to 10 μg of input DNA per experiment, the kit provides sufficient reagents for 25 reactions. Store at 4°C. For long-term storage > 6 months, MBD2-Fc protein should be stored at -20°C.