Buffer List

Name Useful pH Range (pKa1) Useful pH Range (pKa2) Useful pH Range (pKa3) Note
ACES 6.1 - 7.5

Absorbs UV at 230 nm, binds Cu2+

Acetate 3.6 - 5.6
ADA 6.0 - 7.2

Absorbs UV under 260 nm, binds metal ions

Ammonia 8.8 - 9.9
AMP 9.0 - 10.5
AMPD 7.8 - 9.7
AMPSO 8.3 - 9.7
Barbital 6.8 - 9.2
BES 6.4 - 7.8

Binds Cu2+

Bicine 7.6 - 9.0

Binds Cu2+

Bis-Tris 5.8 - 7.2
Bis-Tris Propane 6.3 - 9.5
Borate 8.5 - 10.2

Forms covalent complexes with sugars, ribonucleotides, and glycerol

CABS 10.0 - 11.4
Cacodylate 5.0 - 7.4

Toxic

CAPS 9.7 - 11.1
CAPSO 8.9 - 10.3
Carbonate 6.0 - 8.0 9.5 - 11.1

Equilibrates with CO2

CHES 8.6 - 10.0
Citrate 2.2 - 6.5 3.0 - 6.2 5.5 - 7.2

Binds some proteins and metals

DIPSO 7.8 - 8.2
EPPS 7.3 - 8.7

Can form radicals

Formate 3.0 - 4.5
Gly-Gly 2.5 - 3.8 7.5 - 8.9

Binds Cu2+

Glycine 2.2 - 3.6 8.6 - 10.6
HEPBS 7.6 - 9.0
HEPES 6.8 - 8.2

Can form radicals

HEPPSO 7.1 - 8.5

Can form radicals

Imidazole 6.2 - 7.8

Forms complexes with divalent cations

Malate 2.7 - 4.2 4.0 - 6.0
Maleate 1.2 - 2.6 5.5 - 7.2

Absorbs in UV range

MES 5.5 - 6.7
MOBS 6.9 - 8.3
MOPS 6.5 - 7.9

Degrades when autoclaved with glucose

MOPSO 6.2 - 7.6
Phosphate 1.7 - 2.9 5.8 - 8.0

Inhibits some enzymes, precipitates with divalent cations, pKa affected by dilution

Phthalate 4.1 - 5.9
PIPES 6.1 - 7.5

Can form radicals

POPSO 7.2 - 8.5
Pyridine 4.9 - 5.9
Succinate 3.2 - 5.2 5.5 - 6.5
TABS 8.2 - 9.6
TAPS 7.7 - 9.1
TAPSO 7.0 - 8.2
Taurine 8.4 - 9.6
TES 6.8 - 8.2

Binds Cu2+

Tricine 7.4 - 8.8

Binds Cu2+

Triethanolamine 7.3 - 8.3
Tris 7.0 - 9.0

Highly temperature sensitive, affected by dilution, forms Schiff's base with aldehydes and ketones