Detects whether a binding protein can attach to the specific DNA sites and thus provides information on the binding site and on the protein. The analysis is carried out by combining DNA and binding proteins and followed by treatment with methylating enzyme. If the protein binds to a specific guanine site(s), that base will not be methylated. Piperidine breaks DNA at bases modified by methylation, and sites protected from methylation by bound protein are not cleaved by peperidine. methylation of DNA; Shaw PE, Stewart AF 2001 Methods Mol Biol 148:221.