Phosphate buffered saline

Phosphate buffered saline (abbreviated PBS) is a buffer solution commonly used in biochemistry. It is a salty solution containing sodium chloride, sodium phosphate and potassium phosphate. The buffer helps to maintain a constant pH. The concentration usually matches the human body (isotonic).

PBS has many uses because it is isotonic and non-toxic to cells. It can be used to dilute substances. It is used as a cellular cleaning solution. In addition, PBS is also used to disengage attached and clumped cells.

To make a 10 liter stock of 10x PBS:

1. weigh the following

• 800 g NaCl
• 20 g KCl
• 144 g Na₂HPO₄
• 24 g KH₂PO₄

1. add and dissolve in 8 L of distilled water under mixing
2. pH is ~6.8, but when you dilute the 10x PBS to 1x PBS it should change to 7.4 (try with a little sample; Phosphate buffers change their pH with the dilution)
3. fill up to 10 L with distilled water