PMID: 2388Feb 1, 1976

Determination of the molar absorptivity of NADH

Clinical Chemistry
R B McCombG N Bowers


The molar absorptivity of NADH at 340 nm has been determined by an indirect procedure in which high-purity glucose is phosphorylated by ATP in the presence of hexokinase, coupled to oxidation of the glucose-6-phosphate by NAD+ in the presence of glucose-6-phosphate dehydrogenase. The average value from 85 independent determinations is 6317 liter mol-1 cm-1 at 25 degrees C and pH 7.8. The overall uncertainty is -4.0 to +5.5 ppt (6292 to 6352 liter mol-1 cm-1), based on a standard error of the mean of 0.48 ppt and an estimate of systematic error of -2.6 to +4.1 ppt. Effects of pH, buffer, and temperature on the molar absorptivity are also reported.

Related Concepts

Process of Absorption
Adenosine Triphosphate, Chromium Ammonium Salt
Glucose, (beta-D)-Isomer
Glucosephosphate Dehydrogenase
Hexokinase 2
Hydrogen-Ion Concentration
Spectrophotometry, Ultraviolet

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