Phosphate buffered saline (PBS) is a very common solution in molecular biology, cell culture, and histology. It is isotonic and is often used to maintain a stable pH during cell culture or rinsing of fixed cells. PBS is also available from multiple vendors as pre-made 1x or 10x solutions, or as PBS buffer tablets than can be directly dissolved in water. 10x concentrations are best stored at room temperature following sterilization (autoclaving) while 1x solutions can be stored at 4 degrees C.
1. Measure out 800 ml distilled water into a glass beaker or container. Dissolve the following in the water:
80 grams NaCl
2 grams KCl
14.4 grams of Na2HPO4
2.4 grams KH2PO4
2. To quickly dissolve the solute, place a magnetic stir bar in the glass container and allow it gently agitate the liquid for 10 minutes.
3. Bring volume to 1 L by adding distilled water.
4. Adjust pH of the solution to 7.4
5. Autoclave and then store at room temperature.
For 1 x PBS, dilute the above solution 1:10 in distilled water.