DETERMINATION OF NAD(P)H BY A BIOLUMINESCENT ENZYME FIBER OPTIC PROBE

A fiber optic probe was interfaced to a photon counting system for the determination of nicotinamide adenine dinucleotide reduced [NAD(P)H] by a bioluminescence method. The reagents employed in a bacterial luci ferase/flavin mononucleotide /decanal system were optimized. Attempts were made to increase the quantum yield of the system. Dodecanal, trid ecanal, and tetradecanal were evaluated as alternative aldehyde reagen ts for decanal, and hydrogen peroxide was added to the system. Neither attempt increased the quantum yield of the system. However, a relativ ely low detection limit of 1.6 x 10(-9) M for NAD(P)H was obtained wit h a linear dynamic range of 3.8 orders of magnitude. These results dem onstrate the sensitivity of this instrumentation and assay.