PBS (phosphate buffered saline) is a commonly used buffer for immunohistochemical staining. It is used as a wash solution and for diluting antibodies. The buffer recipe provided here is for 10X PBS stock solution (0.1M). An option for added Tween is also provided.
Difficulty: Easy
Time Required: 10 minutes
Here's How:
- Weigh the following: 10.9g anhydrous sodium phosphate dibasic (Na2HPO4), 3.2g anhydrous sodium phosphate monobasic (NaH2PO4), and 90g sodium chloride (NaCl).
- Dissolve all of the above in just under 1L distilled water.
- Adjust the pH to 7.4.
- Make the solution up to a final volume of 1L.
- (optional) For a solution containing 0.5% Tween 20, add 5mL Tween 20 to the 1L solution.
- Dilute 10X prior to use and readjust pH if necessary.
Tips:
- Store at room temperature.
- Non-anhydrous reagents may be substituted but you'll have to recalculate the appropriate mass of each to use, making accomodation for the added water molecules.
What You Need
- Sodium phosphate monobasic (anhydrous)
- Sodium phosphate dibasic (anhydrous)
- Sodium chloride
- Scale and weigh boats
- Magnetic stirrer and stir bar
- pH probe, calibrated, and appropriate solutions for adjusting pH
- 1L volumetric flask
- Tween 20 (optional)