Abstract
A modification of a kinetic determination of 5''-nucleotidase (EC 3.1.3.5) activity is described. Special attention was paid to the stabilization of glutamate dehydrogenase (EC 1.4.1.2) by L-leucine, optimal NADH concentration and the influence of endogeneous NH3. The optimal concentrations of the other constituents of the reagent were checked with optimal values given in the literature. Normal values were determined. The proposed method shows a good correlation with a colorimetric reference method.