<select Language> bio:リン酸バッファー|日本語 bio:en:phosphate buffer|English </select>
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 Good's buffers for biological assays.
The preparation of phosphate buffer by Sørensen's method.
Mix the following volumes of A and B, and add equal volume of H2O to result [phosphate] = 0.1M.
Stock solution A | 0.2 M NaH2PO4 |
---|---|
Stock solution B | 0.2 M Na2HPO4 |
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 |