A Note on Serum Nucleotidase Determinations

Current methods for estimating 5'-nucleotidase activity in human serum are critically discussed. The requirements for specificity in the assay procedure are re-emphasised, special consideration being given to the absolute concentrations as well as the molar ratios of true and alternative substrates. Substrate-inhibition, described in a previous Report is believed to be due to a non-linear relationship between AMP concentration and optical density above 0.1 mM. Die gegenwärtig gebrauchten Methoden zur Bestimmung der 5'-Nucleotidaseaktivität von menschlichem Serum werden kritisch be-sprochen. Die Erfordernisse für die Spezifität des Bestimmungsverfahrens werden nachdrücklich hervorgehoben; besondere Überle