Description; Application; Cytosine has been used: • for the preparation of nucleobase solutions • as a standard for high-performance liquid chromatography (HPLC) • for the estimation of global methylation rate • for nucleoside 5′-triphosphate (NTP) synthesis • purification; Packaging; 1, 5, 10, 25, 100 g in poly bottle; Biochem/physiol Actions; Cytosine (C) is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA).; Cytosine is a pyrimidine, which forms three hydrogen bonds to base pair with guanine. It forms a nucleotide cytidine, that is phosphorylated to cytidine 5′ monophosphate (CMP), cytidine 5′ diphosphate (CDP) and cytidine 5′ triphosphate (CTP).