PBS

1x PBS is 137 mM NaCl, 12 mM Phosphate, 2.7 mM KCl, pH 7.4

To make 10x PBS

1. Combine the following:
   • 80 g NaCl
   • 2 g KCl
   • 14.4 g Na₂HPO₄ (dibasic anhydrous) OR 18.1 g Na₂HPO₄ · 2H₂O (dibasic dihydrate) OR 27.2 g Na₂HPO₄ · 7H₂O (dibasic heptahydrate)
   • 2.4 g KH₂PO₄ (monobasic anhydrous)
   • 800 mL distilled H₂O
2. Adjust pH to 7.4 with HCl
3. Add H₂O to 1L
4. Autoclave for 20 minutes on liquid cycle. Store at RT.
   
   PBST: For some applications (washing) one adds Tween 20 to PBS which makes PBST

• • Usual concentrations of Tween 20 in PBST are 0.1 or 0.05%.
  • Usual concentration of Triton X-100 in TBST is 0.1-0.3%.