V i s u a l i z a t i o n N o t e s

Visualization Notes

Direct Autoradiography

Prepare the gel in the usual manner and expose to film as directed with the instructions accompanying the film. Exposure times, especially for medium energy beta-emitters such as 14C and 35S can be quite long. For maximum sensitivity of these types of labels,

use fluorography.

Fluorography

Fluorography intensifies a weak beta emission signal by impregnating the gel with a suitable fluor that converts beta emission from 35S, 14C, and 3H into light. Drying the gel in cellophane does not quench this signal, but for 3H, a very weak beta-emitter, up to 20% of the signal may be lost.

If using EN3HANCE or sodium salicylate as fluorography agents, include 0.5% to 2% glycerol in the cold water treatment prior to drying. Dehydration steps are not required for thinner, lower percentage gels, which are far less prone to cracking. If exposed to the maximum drying temperature (≈54 °C), these gels may form longer fluor crystals, resulting in higher background on X-ray exposures.

NOTE Certain fluorographic agent manufacturers specify temperatures higher than

those reached in the Hoefer Easy Breeze (e.g. Autofluor™ [National Diagnostics] and Fluoro-Hance™ [Research Products International], which require up to 80 °C to produce an optimum signal). This dryer is not recommended for such agents.

Bibliography

Juang, R.H., Chang, Y.D., Sung, H.Y., and Su, J.C., Oven-drying method for polyacrylamide gel slab packed in a cellophane sandwich. Anal. Biochem. 141, 348–350 (1984).

Laskey, R.A., The use of intensifying screens or organic scintillators for visualizing radioactive molecules resolved by gel electrophoresis. (In Methods in Enzymology, 65, L. Grossman and K. Moldave, eds.) Academic Press, N.Y. 365–371 (1980).

Perng, G.S., Rulli, R.D., Wilson, D.L. and Perry, G.W., A comparison of fluorographic methods of detection of 35S labeled proteins in polyacrylamide gels. Anal. Biochem. 173, 387–392 (1988).

Hoefer SE 1200 Easy Breeze Air Gel Dryer

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