Used in biochemical assays to study enzyme activity, particularly in detecting and quantifying NAD-dependent enzymes such as dehydrogenases. Biotin-NAD serves as a coenzyme analog that allows for the immobilization and capture of target enzymes via streptavidin-biotin interaction, enabling sensitive detection in ELISA-like formats and pull-down assays. It is also applied in high-throughput screening to identify enzyme inhibitors or activators. Its biotin tag facilitates easy separation and purification of enzyme complexes in metabolic research.