enzymatic footprinting methylation interference assay In interference assays, the DNA will be methylated before the binding assay. Protein binding to DNA protects DNA from methylation by dimethylsulphate. If the contact points are methylated, the protein binding is prevented. After isolating the protein-DNA complex, the methylation sites are cleaved by chemical method. As a result, only those regions out of the binding sites will be cleaved. The protein binding region is not methylated; hence, this region is not cleaved. Although the pattern looks like a footprint, the blank region means "contact points". methylation protection assay methylation interference orchard contact point analysis 2012-06-07T02:54:00Z PSI-MI MI:1189