PBS stands for phosphate buffered saline and is often used because it is isotonic to cells.
1x PBS is 137 mM NaCl, 12 mM Phosphate, 2.7 mM KCl, pH 7.4
To make 10x PBS,
- 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
- Adjust pH to 7.4 with HCl
- Add H2O to 1L
- Autoclave for 20 minutes on liquid cycle. Store at RT.
- PBST: For some applications (washing) one adds Tween 20 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%.