This product includes 20 ml of Reagent P1 and 0.2 ml of 100 x Reagent P2 and 0.05 ml of 1 mM potassium phosphate (KH2PO4). It is for 200 assays using 96-well plates (100 ul of sample volume) or 800 assays using 384-well plates (25 ?l of sample volume). The following protocol is for assays using 96-well plates. Cuvettes may also be used for the measurement.