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.

Table 1 Active pH Range of Good’s Buffers

Good’s Buffer pKa (20℃) pH
MES 6.15 5.5-7.0
Bis-Tris 6.46 5.7-7.3
ADA 6.60 5.8-7.4
PIPES 6.80 6.1-7.5
ACES 6.90 6.0-7.5
MOPSO 6.95 6.2-7.4
BES 7.15 6.6-8.0
MOPS 7.20 6.5-7.9
TES 7.50 6.8-8.2
HEPES 7.55 6.8-8.2
TAPSO 7.70 7.0-8.2
POPSO 7.85 7.2-8.5
HEPPSO 7.90 7.4-8.6
EPPS 8.00 7.5-8.5
Tricine 8.15 7.8-8.8
Bicine 8.35 7.7-9.1
TAPS 8.40 7.7-9.1
CHES 9.50 8.6-10.0
CAPS 10.4 9.7-11.1

 

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 Buffer
ACES
25 g
100 g
GB02 Good Buffer
ADA
25 g
100 g
GB03 Good Buffer
BES
25 g
100 g
500 g
GB04 Good Buffer
Bicine
25 g
100 g
GB05 Good Buffer
Bis-Tris
25 g
100 g
GB06 Good Buffer
CAPS
25 g
100 g
GB07 Good Buffer
CHES
25 g
GB09 Good Buffer
EPPS
25 g
GB10 Good Buffer
HEPES
25 g
100 g
250 g
500 g
GB11 Good Buffer
HEPPSO
25 g
GB12 Good Buffer
MES
25 g
100 g
250 g
500 g
GB13 Good Buffer
MOPS
25 g
100 g
250 g
500 g
GB14 Good Buffer
MOPSO
25 g
GB15 Good Buffer
PIPES
25 g
100 g
500 g
GB16 Good Buffer
POPSO
25 g
GB17 Good Buffer
TAPS
25 g
100 g
GB18 Good Buffer
TES
25 g
100 g
500 g
GB19 Good Buffer
Tricine
25 g
100 g
GB20 Good Buffer
TAPSO
25 g
GB25 Good Buffer
PIPES sesquisodium
25 g

Product Classification

Product Classification

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