Cellulose Acetate

Only continuous buffer systems are suitable for electrophoresis in cellulose acetate gel. The gel and the electrode buffers are usually of the same ionic strength.

1. Phosphate-citrate (pH 6.4)8

10 mM phosphate (sodium dibasic) 2.5 mM citric acid Modifications: There are numerous modifications of this buffer concerning the pH value (varies from pH 5.0 to 7.5) and final concentrations of phosphate (varies from 5 to 100 mM) and citrate (varies from 1.5 to 35 mM) constituents.

20 mM phosphate (sodium dibasic), adjusted to pH 7.0 with 20 mM phosphate (sodium monobasic) Modifications: There are numerous modifications of this buffer concerning the pH value (varies from pH 6.5 to 7.5), the final concentration of phosphate (varies from 10 to 40 mM), and the presence of some additional components (e.g., magnesium chloride, EDTA, 2-mercaptoethanol, Triton X-100) used to activate or preserve an enzyme under analysis or to improve resolution of its isozymes.

10 mM Tris 1 mM EDTA 10 mM maleic acid 1 mM MgCl2

Note: Dissolve buffer components in the indicated order to prevent formation of insoluble products. Adjust to pH 7.4 using sodium hydroxide. Modifications: There are modifications of this buffer concerning the pH value (varies from pH 6.0 to 7.8), the final concentration of Tris (varies from 15 to 100 mM), and the absence of EDTA or magnesium chloride.

20 mM Tris, adjusted to pH 7.5 with saturated solution of citric acid Modifications: There are numerous modifications of this buffer concerning the pH value (varies from pH 5.0 to 8.6), the final concentration of Tris (varies from 10 to 100 mM), and the presence of EDTA (varies from 2 to 4 mM).

15 mM Tris

5 mM EDTA (disodium salt) 10 mM MgCl2 5.5 mM boric acid

Note: Use boric acid to adjust pH to 7.8. Modifications: Most modifications are minor and concern adjustments of pH (range from 7.8 to 9.0), the final concentration of Tris (varies from 15 to 130 mM), and the presence of magnesium chloride (varies from 1 to 10 mM).

25 mM Tris 192 mM glycine Modifications: Most modifications are minor and concern adjustments of pH (range from 8.5 to 9.0).

General Notes: It should be taken into account that the use of highly concentrated buffers can draw a large current that may cause overheating of the gel. Thus, the progress of an electrophoretic run should be carefully monitored, even when electrophoresis is carried out in a refrigerator at 4°C or in a cold room at nearly 0°C.

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