Continuous Flow Curtain Electrophoresis

 

This procedure is a simple and logical extension of two-dimensional paper electrophoresis and is diagrammatically depicted in figure 21.

 

 

 

 

Figure 21. Continuous Two-Dimensional Paper Electrophoresis

 

The system is arranged such that there is a continuous downward curtain-flow of electrolyte on a vertically held sheet of filter paper. At the same time the sample is continuously fed onto the paper at a spot at the top of the paper. There is a potential applied across the paper from electrodes situated along the side edges; the left hand edge is held at a positive potential and, thus, is made the anode and right hand edge held at a negative potential and, thus, is made the cathode.

 

As a consequence, anions migrate laterally to the anode while travelling downward in the curtain flow, and the cations migrate laterally towards the cathode. Thus, each ion travels at an angle across the paper and exits at a specific point on the lower horizontal edge of the paper. The bottom edge of the paper is often serrated to provide fixed exit positions to facilitate sample collection along the paper edge. 

 

The angle of deflection of the sample () is given by the following equation,

 

 

The loading of the system is limited by the carrying capacity of the buffer. Nevertheless, commercial instruments are available and the system is still in general, if perhaps, limited, use.