Methylation Sensitive Restriction Enzymes
A Protocol for Digestion with Methylation-Sensitive Enzymes followed by PCR.
This method uses methylation-sensitive restriction enzymes, to cleave DNA at specific methylated-cytosine residues which have lost their methyl group, that are followed by a guanine, CpG, followed by amplification of the resultant products. The amplification products are only detected when digestion of the products are inhibited by methylation being present. This method, because of the PCR used to amplify small amounts of DNA, is highly sensitive. Its major disadvantage is incomplete digestion of the DNA material by the restriction-enzymes that will result in false-positives. It is therefore crucial to fully digest the DNA prior to PCR amplification.
R.Sadri et al. Rapid analysis of DNA methylation using new restriction enzyme sites created by bisulfite modification. Nucleic Acids Res. (1996) 24: 4987-4989