Bio-Rad Whole Gel Eluter and Mini Whole Gel Eluter - Manual (Page 22)

For this reason, 6% polyacrylamide gels are recommended for most applications. For very
large proteins 4% or 5% gels may be used.
Continuous and Elution Buffer Systems
McLellan describes various continuous buffer systems from pH 3.8 to pH 10.2 all with
the same ionic strength. 2 Use the table below to prepare 5x continuous, non-denaturing buffers.
Add both the acidic and basic components to 1 liter of water. Do not adjust pH with acid or
base. If the final pH is outside the listed range, discard the buffer and remake it.
Buffer Basic 5X Acidic 5X
pH±0.1 component solution component solution
and MW g/L or ml/L and MW g/L or ml/L
Beta-Alanine Lactic Acid
3.8 89.09 mw 13.36 g/L 85% soln. 7.45 ml/L
Beta-Alanine Acetic Acid
4.4 89.09 mw 35.64 g/L 17.4 M 11.5 ml/L
GABA Acetic Acid
4.8 103.1 mw 41.24 g/L 17.4 M 5.75 g/L
Histidine MES
6.1 155.2 mw 23.28 g/L 195.2 mw 29.5 g/L
Histidine MOPS
6.6 155.2 mw 19.4 g/L 209.3 mw 31.4 g/L
Imidazole HEPES
7.4 68.08 mw 14.64 g/L 238.33 mw 41.7 g/L
Tris EPPS
8.1 121.14 mw 19.38 g/L 252.2 mw 37.85 g/L
Tris Boric Acid
8.7 121.14 mw 30.29 g/L 61.83 7.73 g/L
Tris CAPS
9.4 121.14 mw 36.34 g/L 221.3 mw 44.26 g/L
Ammonia CAPS
10.2 14.8 M 12.5 ml/L 221.3 mw 22.13 g/L
To make 1 liter of 1X elution buffer, dilute 200 ml of 5X buffer with 800 ml deionized
water. The final concentrations of buffer components will be:
Buffer pH Basic Component Acidic Component
3.8 30 mM Beta-Alanine 20 mM Lactic Acid
4.4 30 mM Beta-Alanine 40 mM Acetic Acid
4.8 80 mM GABA 20 mM Acetic Acid
6.1 30 mM Histidine 30 mM MES
6.6 25 mM Histidine 30 mM MOPS
7.4 43 mM Imidazole 35 mM HEPES
8.1 32 mM Tris 30 mM EPPS
8.7 50 mM Tris 25 mM Boric Acid
9.4 60 mM Tris 40 mM CAPS
10.2 37 mM Ammonia 20 mM CAPS
20