2'-Deoxyuridine-5'-13C is a stable isotope-labeled nucleoside derivative, where the carbon-13 (13C) isotope is incorporated at the 5' position of the deoxyribose sugar. This compound serves as a valuable tool in metabolic studies, nucleic acid research, and drug development, particularly for tracing metabolic pathways and investigating nucleotide metabolism. The 13C labeling enables precise detection and quantification using techniques such as NMR spectroscopy and mass spectrometry, enhancing analytical accuracy. Its high isotopic purity and chemical stability make it suitable for in vitro and in vivo studies, providing insights into DNA synthesis, repair mechanisms, and enzyme kinetics. The labeled deoxyuridine is also used in the development of antiviral and anticancer agents, offering researchers a reliable reference standard.