Block electrophoresis on agarose

Zone electrophoresis is useful for the separation of electrophoretically distinct antibodies or proteins. It is easy and reproducible, but the sample size is limited. The technique presented here is essentially 

The Ig are recovered from 0.5 cm slices of the block cut perpendicular to the direction of electrophoresis. The slices are frozen in centrifuge tubes (—20°C), quickly thawed and the agarose is pelleted at 30000 xg for 30 min. The pellets are washed 3 more times with 100 mM Tris-HCl buffer, pH 8.0, containing 500 mM NaCl. The protein content of the combined supernatants is measured by the Lowry method. 

Several pure fractions of Ig are obtained. Yield is about 75%. 

This method has also been applied successfully to the purification of IgE (Lehrer, 1979). 

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