5-Hydroxy-CTP is a modified cytidine triphosphate with a hydroxyl group at the 5-position carbon. This modification significantly alters the chemical properties and biological functions of the nucleotide. During in vitro mRNA synthesis, 5-hydroxy-CTP can be incorporated into RNA molecules, generating RNA containing 5-hydroxycytidine. RNA with hydroxyl modification plays an important role in studying RNA structure, function, and interactions with proteins. Additionally, 5-hydroxy-CTP significantly improves RNA stability and reduces intracellular degradation. Thus, this modification has extensive applications in gene expression research, RNA therapeutic development, and gene therapy.