To maintain a constant value, the activity of the alkaline phosphatase, serum containing this control phosphatase

摘要

The activity of alkaline phosphatase in aqueous solution, especially in reconstituted serum, is kept constant by adding to the phosphatase-containing solution Mn2+ or Cd2+ ions, preferably to an end concentration of 0.05 to 0.5 mMol/liter of Mn2+ or 0.05 to 0.1 mMol/liter of Cd2+. Control serums comprising the Mn2+ and/or Cd2+ ions in human or animal serum or serum-like compositions are also provided.