14Clabeled

14C-labeled refers to molecules in which one or more carbon atoms are replaced with the radioactive isotope carbon-14, enabling tracking and quantification in experiments. Carbon-14 has a half-life of about 5,730 years and decays by beta emission to nitrogen-14, with detectable emissions used in a range of analytical techniques.

Production and labeling are typically achieved by generating carbon-14 in a nuclear reactor and converting it into usable labeled reagents. Common sources include 14CO2, 14CH3I, and other 14C-labeled precursors that can be incorporated into target molecules. Researchers choose site-specific, positional, or uniform labeling depending on the desired information about a molecule’s fate or reaction mechanism.

Detection and analysis of 14C-labeled compounds rely on radiometric and spectrometric methods. Liquid scintillation counting, gas proportional counting, and Cherenkov counting provide quantitative measures of radioactivity. Autoradiography allows imaging of labeled samples, while accelerator mass spectrometry (AMS) offers highly sensitive detection of very low 14C levels, enabling detailed pharmacokinetic and metabolic studies.

Applications of 14C labeling span several fields. In biomedical research, it is used to trace metabolic pathways, measure drug absorption and excretion, and study distribution and clearance. Environmental science employs 14C labels to follow the fate of chemicals and assess ecological impact. In basic chemistry and biochemistry, labeling aids in mechanistic studies and structural investigations, including nucleic acid and protein research.

Safety and regulation are important considerations. 14C emits low-energy beta radiation, with external exposure typically low; handling occurs under radiation safety guidelines, with sealed sources and appropriate waste disposal. Work is conducted under institutional and national regulatory oversight to ensure safe use and disposal of radioactive materials.