The quality control of alkaline phosphatase determinations with placental phosphatase

Human placenta has been recommended as the source of the alkaline phosphatase used for the preparation of control or reference materials. The effect of certain inhibitors, which may be present in the reagents, on control materials containing the placental isoenzyme, is shown to differ significantly from their effect on the isoenzymes in patient's sera. This finding indicates that if control materials are used which contain only human placental alkaline phosphatase, changes in accuracy resulting from differences in reagent quality may be missed, or alternatively a change in accuracy may be indicated by the quality control results which does not apply to the patient's sera.