Quality Control: Phosphatase, acid from potato (Sigma cat. P1146)and alkaline from bovine intestinal mucosa (Sigma cat. no. P6772) were serially diluted in Assay Buffer-acidic and Assay Buffer-alkaline respectively. The activity of both phosphatases were measured with ScienCell™ pNPP PhosphataseAssay after a given time of reaction (15 min and 45 min).