Translator for HPLC HINTS and TIPS for Chromatographers

Saturday, October 7, 2017

Preparation of Phosphate Buffered Saline (PBS)


While not commonly used in liquid chromatography, PBS solution is commonly used in preparing samples. Because chemical forms and grades vary, there are several recipes on the web. By popular request, I am provided a common laboratory recipe for a 1X PBS solution here.

To make Phosphate Buffered Saline (PBS), 1x pH 7.4 solution:


1. To a 1-liter Beaker, add the following four anhydrous salts:

a. 200 mg KCI

b. 8,000 mg NaCI

c. 240 mg KH2PO4

d. 1,400 mg Na2HPO4

2. Add about 850 ml of deionized water and stir to dissolve the salts. Adjust the pH to 7.4 with 10% phosphoric acid (phosphate solutions should be adjusted with phosphoric acid only). Transfer to a 1 L volumetric flask (class-A). Fill to the “line” with more deionized water. Cap and mix a final time to insure a uniformly mixed solution.
3. Filter the final solution through a suitable 0.22 micron filter before use.

Note: pH increases with decreasing temperature.