Nicotinamide adenine dinucleotide (NAD+) is a dinucleotide coenzyme present in all living cells, consisting of adenosine monophosphate and nicotinamide mononucleotide moieties linked via a phosphoanhydride bond, with a molecular weight of 663.43 g/mol in its oxidized form. As a central redox carrier, NAD+ functions as an obligate electron acceptor in glycolysis, the tricarboxylic acid (TCA) cycle, and mitochondrial beta-oxidation, cycling between its oxidized (NAD+) and reduced (NADH) states to facilitate electron transport chain activity and ATP synthesis. Beyond its redox role, NAD+ serves as a consumed substrate for a distinct class of NAD+-dependent enzymes including the sirtuin deacylases (SIRT1-7), poly(ADP-ribose) polymerases (PARPs), and the cyclic ADP-ribose synthase CD38 that cleave the glycosidic bond to generate ADP-ribose derivatives as signaling intermediates. This 1000mg research vial is supplied for biochemical, cell-based, and cell-free investigations into NAD+ metabolism, redox signaling, and enzyme substrate utilization. For in vitro research use only. Not for human or veterinary administration.