Phosphate-buffered saline (abbreviated PBS) is a buffer solution that is frequently used in biological research, including phage work. It is a salt solution based on water that contains disodium hydrogen phosphate, sodium chloride, and, in some formulations, potassium chloride and potassium dihydrogen phosphate. The buffer aids in the maintenance of a constant pH. It is typically supplied as a tablet that is ready to be dissolved to achieve the desired concentration.
Preparation
Requirements
Content |
Concentration |
|---|---|
| Phosphate buffer | 10 mM |
| Sodium chloride | 137 mM |
| Potassium chloride | 2.7 mM |
| Distilled water | 100 ml |
Procedure
Dissolve one tablet in 100 ml of a 1X solution. 1X PBS solution contains10 mM phosphate buffer, 137 mM sodium chloride, and 2.7 mM potassium chloride. Each tablet prepares a 1X PBS solution when dissolved in 100 ml of distilled water H2O. Adjust the pH to 7.2 with HCl. Dispense the solution into aliquots and sterilize them by autoclaving for 20 min at 15 psi (1.05 kg/cm2) on a liquid cycle or by sterile filter membrane 0.45 lm units. Store PBS at roomtemperature.