Beta-Nicotinamide Adenine Dinucleotide (NAD+) — critical coenzyme in cellular redox chemistry. Reference standard for in-vitro PARP enzyme activation, sirtuin (SIRT1-7) deacylase activity assays, and NAD+/NADH ratio studies in metabolic and aging pathway research. Lyophilized. >99% HPLC purity. For research use only (RUO). Not for human or veterinary use.