[The alkaline phosphatase activity in the lyophylized commercial control sera after reconstitution]

Soon after the reconstitution of the lyophylized commercial control sera the alkaline phosphatase activity is smaller than stated value and theoretical value is reached after a time varying according to the various sera; at any rate this value is hever higher than seven hours since reconstitution. The lyophylized sera reconstitution with a solution of diethanolamine 1 mol/l or MgCl2 0,5 mmol/l alone or associate consents to restore much more swiftly the enzymatic activity to a higher value than 90% of the stated value since reconstitution. No alkaline phosphatase variation is observed in the congealed human sera at --20 degrees C after the decongealment. We recommend to reconstitute the lyophylized sera for the alkaline phosphatase determination by the use of a solution of diethanolamine 1 mol/l and MgCl2 0,5 mmol/l instead of distilled water.