Cytidine is a naturally occurring nucleoside composed of the pyrimidine base cytosine attached to a ribose sugar. It is widely used in biochemistry and molecular biology research as a key component in nucleic acid metabolism and enzyme studies. Cytidine serves as a precursor for the synthesis of nucleotides such as CMP, CDP, and CTP, which are essential building blocks for RNA. It is employed in the production of oligonucleotides for probing genetic functions and in investigations of cellular processes, including transcription, translation, DNA repair, and replication. Additionally, cytidine is utilized in nutritional supplements and pharmaceutical formulations to support cellular health and metabolism.