Does urea promote the bisulfite-mediated deamination of cytosine in DNA?
Hikoya Hayatsu1, Katsumi Tsuji2 and Kazuo Negishi3 1 School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Okayama 703-8516, Japan, 2 Biotechnology Frontier Project, Toyobo Co., Ltd., 10-24 Toyocho, Tsuruga, Fukui 914-0047, Japan, 3 Department of Health and Medicine, Nihon Pharmaceutical University, 10281 Komuro, Ina-cho, Kita-Adachi-gun, Saitama 362-0816, Japan Methylation of cytosine in DNA at position 5 plays important roles in gene functions. Changes in the methylation status are linked to cancer. These studies have been developed on the basis of determining 5-methylcytosine residues [mC] in DNA. This analytical procedure uses the principle that bisulfite deaminates cytosine [C] but it deaminates mC only very slowly. Thus, bisulfite genomic sequencing involves treatment of a given DNA sample with bisulfite followed by PCR amplification and sequencing, through which C residues in the original DNA are found as T and mC as C. In this procedure, a treatment with 3-5 M sodium bisu
