TBS and TBST are used to maintain pH within a very narrow range for a variety of applications including western blotting and immunoassays. The final concentration of a 1X working solution is 137mM NaCl, 2.7mM KCl, 50mM Tris. In addition, 1X TBST contains 0.1% 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