AP Buffer (100mM Tris-HCl, 100mM NaCl, 5mM MgCl₂, 0.05% Tween 20, pH 9.5):

       Tris-HCl (MW 157.60) --------------------- 15.8 g

       NaCl (MW 58.44) --------------------------- 5.8 g

       MgCl₂ (MW 203.31) ------------------------ 1.02 g

       Distilled water ----------------------------- 900 ml

       Mix to dissolve. Adjust pH to 9.5 and then bring total volume to 1 liter. Add 0.5 ml Tween 20. Store this solution at room temperature.