CpG Methylase completely methylates all cytosines in double-stranded, non-methylated, and hemimethylated DNA in a 5’…CpG…3′ context. The recombinant methylase is isolated from an E. coli strain that expresses the methyltransferase gene from Spiroplasma sp. strain MQ1. Reaction conditions have been optimized to maximize the processivity of the enzyme to ensure rapid, complete, and reproducible methylation of DNA for accurate DNA methylation analysis. This product is supplied with 10X Reaction Buffer and S-adenosylmethionine cofactor.