L-Lysine-13C6,15N2 Hydrochloride is primarily used in research and diagnostic applications as a stable isotope-labeled compound. It serves as a tracer in metabolic studies, allowing scientists to track the incorporation and utilization of lysine in biological systems. This labeled form is particularly valuable in nutritional research, where it helps understand amino acid metabolism, protein synthesis, and turnover rates in humans and animals. Additionally, it is employed in mass spectrometry-based proteomics to enhance the accuracy of quantitative protein analysis. Its use in clinical diagnostics aids in studying metabolic disorders and evaluating dietary interventions.