Because its osmolality and ion concentration closely mimic that of the human body, PBS is commonly used for cell culture applications, as well as HPLC and MS. PBST is a wash buffer and diluent for ELISA. The 1X PBS solution contains 137mN NaCl, 2.7mM KCl and 10mM phosphate. PBST is supplemented with 0.05% Tween-20. Premeasured pouches make 1 liter of 1X buffer solution Just empty the pouch into water and stir - no diluting of stock solutions No pH adjustment necessary Quality and consistency guaranteed Nuclease and protease free Long shelf life