Amplite? Fluorimetric cADP-Ribose Assay Kit. cADP-ribose (cADPR) is a novel Ca2+ messenger derived from NAD+. ADP-riboxyl cyclase (ADPRC) catalyzes the synthesis of cADPR from NAD+, but the reaction can be reversed in the presence of high concentration of nicotinamide, producing NAD+ from cADPR stoichiometrically. The resultant NAD+ can be detected using our newly developed NAD sensor Quest Fluor? NAD reagent. This makes monitoring cADPR in tissues and cell cultures possible in the low nM range. The NAD+ detection using Quest Fluor? NAD reagent is specific to NAD+ and has no reaction to NADH. The fluorescent signal can be readily detected at Ex/Em = 420/480 nm. This assay can be performed in a convenient 96-well or 384-well microtiter plate.