6] 



ELECTROPHORESIS AND CHROMATOGRAPHY 



95 



Fig. 2. Zone column electrophoresis apparatus 

 according to Porath (1956). The packed column 

 is seen to the right, surrounded by a cooling 

 mantle. Below are the electrode vessels with a 

 levelling arrangement. 



shows the zone electrophoresis laboratory in the Institute of Biochemistry, 

 Uppsala, with several columns in operation. In this procedure the zones, 

 after having been separated by electrophoretic migration, are eluted from 

 the column and collected in a standard automatic fraction collector of the 

 type commonly used in chromatographic work. This has the advantage that 

 the columns may be used many times without repacking. In other types of 

 apparatus (see especially Kunkel, 1954) flat horizontal troughs are used. 

 This makes the surface of the supporting medium more easily accessible, 

 so that staining reactions can be applied for the localization of the zones, 

 which may then be isolated by cutting the trough contents accordingly. This, 

 however, makes it necessary to pack the trough anew for each experiment. 

 Experiments in gels often give very sharp separations, but elution is diffi- 

 cult. Paper strip electrophoresis has become extremely popular on account 



