Phosphate buffered saline (PBS)

Reagents

·	Sodium chloride NaCl	40.0g
·	Potassium chloride KCl	1.0g
·	Potassium dihydrogen phosphate anhydrous KH2PO4	1.0g
·	Disodium hydrogen phosphate anhydrous Na2HPO4	4.6g
OR	Disodium hydrogen phosphate dihydrous Na2HPO4.2H2O	5.75g
OR	Disodium hydrogen phosphate dodecahydrous Na2HPO4.12H2O	11.6g
·	Distilled water to make up to 5 L

Method

1.    Weigh out the reagents and place in a 5 L conical flask.

2.    Add distilled water to make 5 L. Mix well.

3.    Check pH. Adjust to pH 7.3 to 7.4.

4.    Pour into storage bottles.

5.    Autoclave at 121°C for 15 minutes. Use a slow exhaust.

6.    Allow to cool, then tighten the lids and label the bottles.

Ten times (10 ×) stock solution

If you require large volumes of PBS in your laboratory, you may find it useful to prepare a stock solution that is ten times the strength of the working solution used in the laboratory procedures.

This is called a ten times stock solution, usually labeled by the abbreviation “10 × stock solution”. Before use, prepare the “working solution” by making a one in ten dilution of the stock solution.

To prepare 1 L of working solution, mix 100 mL of the stock solution with 900 mL of distilled water.

Three recipes for the stock solution are provided for total volumes of 1 L, 2 L and 5 L. Choose the recipe for the volume best suited for your laboratory's requirements.

Remember 5 L of the stock solution is enough to prepare 50 L of the working solution. This may be far more than required for the next few months. 2 L of the stock solution may be an adequate supply of the stock solution.

Reagents for varying volumes of ten times stock solution of PBS

Reagents	Total volume
	1 Litre	2 Litres	5 Litres
NaCl	80.0g	160.0g	400.0g
KCl	2.0g	4.0g	10.0g
KH2PO4	2.0g	4.0g	10.0g
One of the following
Na2HPO4 anhydrous	9.2g	18.4g	45.9g
OR Na2PO4.2H2O	11.5g	23.0g	57.5g
OR Na2HPO4.12H2O	23.1g	46.1g	115.7g

Method

1. Weigh out reagents for the selected total volume of PBS.

2. Mix with distilled water to the required volume. Adjust pH to 7.3.

3. Dispense into sterile glass bottles, sterilize by autoclaving at 121°C for 15 minutes. Use a slow exhaust.

4. When cool, tighten lids and label.