A modified colorimetric method for the determination of orthophosphate in the presence of high ATP concentrations

Abstract We describe a modified colorimetric method that quantitates inorganic phosphate linearly up to 60 nmol, with high stability of the developed color and with a low interference by ATP concentration (up to 30 m m ). This method is very suitable for use in ATPase enzymatic assays, especially with enzymes that have low specific activities and (or) high K m values for ATP.