Phosphate buffered saline

2006-12-07T06:53:05Z

150.65.147.118: I have added three lines on the uses of PBS by appending those to the end of the second paragraph

'''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. To ensure the prolonged dry-storage of immobilized-biomolecules like proteins, enzymatic proteins etc., PBS is used as biomolecule diluent since it can structure water around biomolecules immobilized to the solid surface. Such thin film of water prevents denaturing of biomolecules or conformational changes to them. Carbonate buffers may be used for the same purpose but with less effectiveness.

Additives can be used to add function. For example, PBS with [[EDTA]] is also used to disengage attached and clumped cells. Divalent [[metals]] such as [[zinc]], however, cannot be added as this will cause precipitation. For these sorts of applications, [[Good's buffers]] are recommended.
To make a 10 liter stock of 10x PBS:
#weigh the following
#*800 g NaCl
#*20 g KCl
#*144 g Na2HPO4
#*24 g KH2PO4
#add and dissolve in 8 L of distilled water under mixing
#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)
#fill up to 10 L with distilled water

1x PBS final concentration : 137 mM NaCl, 10 mM Phosphate, 2.7 mM KCl, pH 7.4

{{biochem-stub}}

[[Category:Buffers]]

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Phosphate buffered saline