Phosphate Buffer (0.2M PB, pH 7.4):

       Na2HPO4 (anhydrous) -------------------------- 21.8 g

       NaH2PO4 (anhydrous) -------------------------- 6.4 g

       Distilled water ---------------------------------- 1000 ml

       Mix to dissolve and adjust pH to 7.4

       Store this solution at room temperature.

Phosphate Buffer (0.1M PB, pH 7.4):

       Na2HPO4 (anhydrous) -------------------------- 10.9 g

       NaH2PO4 (anhydrous) -------------------------- 3.2 g

       Distilled water ---------------------------------- 1000 ml

       Mix to dissolve and adjust pH to 7.4

       Store this solution at room temperature.