10X PBS (0.1M PBS, pH 7.4):

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

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

       NaCl ------------------------------------------- 90 g

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

       Mix to dissolve and adjust pH to 7.4

       Store this solution at room temperature. Dilute 1:10 with distilled water before use and adjust pH if necessary.

20X PBS (0.2M PBS, pH 7.4):

       NNa2HPO4 (anhydrous) -------------------- 21.8 g

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

       NaCl ------------------------------------------ 180 g

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

       Mix to dissolve and adjust pH to 7.4

       Store this solution at room temperature. Dilute 1:20 with distilled water before use and adjust pH if necessary.

10X PBS-Tween 20 (0.1M PBS, 0.5% Tween 20, pH 7.4):

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

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

       NaCl -------------------------------------------- 90 g

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

       Mix to dissolve and adjust pH to 7.4 and then add 5 ml of Tween 20

       Store this solution at room temperature. Dilute 1:10 with distilled water before use and adjust pH if necessary.

20X PBS-Tween 20 (0.2M PBS, 1% Tween 20, pH 7.4):

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

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

       NaCl ------------------------------------------ 180 g

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

       Mix to dissolve and adjust pH to 7.4 and then add 10 ml of Tween 20

       Store this solution at room temperature. Dilute 1:20 with distilled water before use and adjust pH if necessary.

Note: PBS buffer is used for routine immunohistochemiscal staining. PBS is often used for diluting secondary antibodies or streptavidin-HRP conjugate. PBS-Tween 20 is often used for washing steps.