Cytosine-13C,15N2 is intended for use as an internal standard for the quantification of cytosine by GC- or LC-MS. Cytosine is a pyrimidine base.[1] It forms complementary base pairs with the purine guanine in DNA and RNA and is a precursor of uracil . Methylation of cytosine is a key epigenetic mark that plays a role in gene regulation.[2]
References:
[1].Berg, J.M., Tymoczko, J.L., and Stryer, L.Nucleotide biosynthesisBiochemistry(2002).
[2].Breiling, A., and Lyko, F.Epigenetic regulatory functions of DNA modifications: 5-Methylcytosine and beyondEpigenetics Chromatin824(2015).