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Phosphate buffered saline

2007-01-21T06:58:24Z

71.133.213.109: /* Applications */

'''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]]).

==Applications==
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. PBS can be used as a reference spectra when measuring the protein adsorption in ellipsometry.

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.

==Preparation==
A 10 liter stock of 10x PBS can be prepared by dissolving 800 g NaCl, 20 g KCl, 144 g Na2HPO4 and 24 g KH2PO4 in 8 L of distilled water, and topping up to 10 L. The pH is ~6.8, but when diluted to 1x PBS it should change to 7.4.

On dilution, the resultant 1x PBS will have a final concentration : 137 mM NaCl, 10 mM Phosphate, 2.7 mM KCl, pH 7.4

{{biochem-stub}}

[[Category:Buffers]]

Phosphate buffered saline

2007-01-21T06:58:07Z

71.133.213.109: /* Applications */

'''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]]).

==Applications==
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.PBS can be used as a reference spectra when measuring the protein adsorption in ellipsometry.

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.

==Preparation==
A 10 liter stock of 10x PBS can be prepared by dissolving 800 g NaCl, 20 g KCl, 144 g Na2HPO4 and 24 g KH2PO4 in 8 L of distilled water, and topping up to 10 L. The pH is ~6.8, but when diluted to 1x PBS it should change to 7.4.

On dilution, the resultant 1x PBS will have a final concentration : 137 mM NaCl, 10 mM Phosphate, 2.7 mM KCl, pH 7.4

{{biochem-stub}}

[[Category:Buffers]]