Classification
Buffers
Introduction
In biological experiments, it is important to maintain the pH of the solutions used. Buffers, mixtures of appropriate weak acids, and their conjugate bases, are usually used. Most biological reactions occur at a neutral pH, from 6 to 8; the buffer needs to be effective in this range. Furthermore, the acids and bases used in the buffer should not produce chelates with metal ions, which are essential in biological systems. For these reasons, Dr. Good developed several aminoethane and aminopropane sulfonic acids that are now widely used for biological research and analysis. Good’s buffers have the following characteristics:
1) High water-solubility
2) Low cell membrane permeability
3) Consistent acid-base dissociation constants
4) Low metal chelating capability
5) High chemical stability
6) Low absorption spectra in UV and visible regions.
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Table 1 Active pH Range of Good’s Buffers
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Preparation of Good’s Buffer Solution ADA, PIPES, POPSO
Solution A: 0.1 mol/l solution
| ADA | 19.02 g + NaOH 4.0 g / 1 L |
| PIPES | 30.24 g + NaOH 4.0 g / 1 L |
| POPSO | 39.85 g + NaOH 4.0 g / 1 L |
Solution B: 0.1 mol/l NaOH solution
| NaOH | NaOH 4.0 g / 1 L |
| Solution A | Solution B | ||||
| 25 ml | 0 ml | 5 ml | 10 ml | 15 ml | 20 ml |
| ADA | 5.8 | 6.6 | 6.9 | 7.3 | 7.8 |
| PIPES | 5.6 | 6.4 | 6.8 | 7.2 | 7.7 |
| POPSO | 6.4 | 7.3 | 7.7 | 8.1 | 8.5 |
Bis-Tris
Solution A: 0.1 mol/l Bis-Tris
Solution B: 0.1 mol/l HCI solution
| Solution A | Solution B | |||
| 25 ml | 0 ml | 5 ml | 10 ml | 15 ml |
| Bis-Tris | 9.5 | 7.1 | 6.6 | 6.1 |
Other Good’s Buffers
Solution A: 0.1 mol/l Good’s Buffer solution
Solution B: 0.1 mol/l NaOH solution
| Solution A | Solution B | ||||
| 25 ml | 0 ml | 5 ml | 10 ml | 15 ml | 20 ml |
| ACES | 4.6 | 6.6 | 7.0 | 7.3 | 7.7 |
| BES | 3.8 | 6.6 | 7.0 | 7.4 | 8.0 |
| Bicine | 5.1 | 7.8 | 8.2 | 8.6 | 10.4 |
| CAPS | 6.8 | 10.0 | 10.5 | 10.8 | 11.2 |
| CHES | 5.9 | 9.0 | 9.4 | 9.7 | 10.1 |
| EPPS | 5.2 | 7.3 | 7.8 | 8.2 | 8.8 |
| HEPES | 5.3 | 7.0 | 7.4 | 7.7 | 8.1 |
| HEPPSO | 5.7 | 7.6 | 7.8 | 8.2 | 8.6 |
| MES | 3.7 | 5.6 | 6.0 | 6.4 | 8.4 |
| MOPS | 3.8 | 6.6 | 7.0 | 7.4 | 8.8 |
| MOPSO | 3.9 | 6.2 | 6.6 | 7.0 | 7.4 |
| TAPS | 4.6 | 7.8 | 8.3 | 8.6 | 9.0 |
| TAPSO | 4.7 | 7.0 | 7.4 | 7.8 | 8.2 |
| TES | 4.4 | 6.7 | 7.4 | 7.7 | 8.2 |
| Tricine | 4.9 | 7.5 | 7.9 | 8.3 | 8.6 |
Product
- Buffers
-
Code Product name Unit size GB01 Good's Buffer
ACES25 g
100 gGB02 Good's Buffer
ADA25 g
100 gGB03 Good's Buffer
BES25 g
100 g
500 gGB04 Good's Buffer
Bicine25 g
100 gGB05 Good's Buffer
Bis-Tris25 g
100 gGB06 Good's Buffer
CAPS25 g
100 gGB07 Good's Buffer
CHES25 g GB09 Good's Buffer
EPPS25 g GB10 Good's Buffer
HEPES25 g
100 g
250 g
500 g
1000 gGB11 Good's Buffer
HEPPSO25 g GB12 Good's Buffer
MES25 g
100 g
250 g
500 g
1 kgGB13 Good's Buffer
MOPS25 g
100 g
250 g
500 g
1 kgGB14 Good's Buffer
MOPSO25 g GB15 Good's Buffer
PIPES25 g
100 gGB16 Good's Buffer
POPSO25 g GB17 Good's Buffer
TAPS25 g
100 gGB18 Good's Buffer
TES25 g
100 gGB19 Good's Buffer
Tricine25 g
100 gGB20 Good's Buffer
TAPSO25 g GB25 Good's Buffer
PIPES sesquisodium25 g
