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Lidstrom:Buffers: Difference between revisions
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→How to chose a buffer for enzyme assays
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** Citric acid binds some proteins and also complexes many metal ions. It's pK<sub>a</sub> values are influenced by the ionic strength of the buffer more than most. | ** Citric acid binds some proteins and also complexes many metal ions. It's pK<sub>a</sub> values are influenced by the ionic strength of the buffer more than most. | ||
*'''Tris""" | *'''Tris""" | ||
** Tris, although widely used, has the disadvantage common to other primary amine buffers of | ** Tris, although widely used, has the disadvantage common to other primary amine buffers of being reactive and forming Schiff bases with aldehyde and ketones. | ||
* '''Glycylglycine''' | * '''Glycylglycine''' | ||
** Glycylglycine binds cetain metal ions; e.g. Mn<sup>2+</sup> and Cu<sup>2+</sup>; it may be degraded by peptidases, it is epxensive, and generally has no advantages over the cheaper Tricine. | ** Glycylglycine binds cetain metal ions; e.g. Mn<sup>2+</sup> and Cu<sup>2+</sup>; it may be degraded by peptidases, it is epxensive, and generally has no advantages over the cheaper Tricine. | ||
* '''Bicarbonate''' | * '''Bicarbonate''' | ||
** Bicarbonate buffer has the disadvantage of | ** Bicarbonate buffer has the disadvantage of having to be used in a closed system to avoid the loss of carbonic acid as CO<sub>2</sub>. | ||
