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en:phosphate_buffer [2013/06/09 10:09] (current)
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 +<select Language>​
 +bio:​リン酸バッファー|日本語
 +bio:​en:​phosphate buffer|English
 +</​select>​
 +
 +======Phosphate buffer======
 +Phosphate buffer is often used for column chlomatography. But it is not an ideal buffer for biological assays because phosphate can act as either a substrate or a regulation factor of enzymes. Besides, the buffering ability decreases significantly at low pH. __Use [[Buffer solution|Good'​s buffers]] for biological assays__.
 +
 +
 +
 +=====Sørensen'​s 0.1M buffer=====
 +
 +The preparation of phosphate buffer by Sørensen'​s method.
 +
 +  *Sørensen, S.P.L.: Biochem Z. 21, 131 (1909) and Biochem. Z. 22, 352 (1909)
 +  *Gomori, G.: Methods Enzymol. Vol. 1, 138 (1955)
 +
 +Mix the following volumes of A and B, and add equal volume of <​chem>​H2O</​chem>​ to result [phosphate] = 0.1M.
 +
 +^Stock solution A|0.2 M <​chem>​NaH2PO4</​chem>​|
 +^Stock solution B|0.2 M <​chem>​Na2HPO4</​chem>​|
 +
 +^pH|5.8|6.0|6.2|6.5|6.6|6.7|6.8|6.9|7.0|7.1|7.2|7.3|7.4|7.5|7.8|8.0|
 +^A (ml)|92.0|87.7|81.5|68.5|62.5|56.5|51.0|45.0|39.0|33.0|28.0|23.0|19.0|16.0|8.5|5.3|
 +^B (ml)|8.0|12.3|18.5|31.5|37.5|43.5|49.0|55.0|61.0|67.0|72.0|77.0|81.0|84.0|91.5|94.7|
 +
 +{{tag>​buffer preparation}}