THE ENGINEERING DESIGN OF CONTINUOUS ELECTROPHORESIS

In the design of continuous electrophoresis devices, the main variables are the gap width, the flow rate and inlet temperature of the buffer, the electric field strength, the point of injection of the proteins, and the orientation of the flow to the gravitational field. Best values for many of these can be derived from first principles by requiring that the flow be stable, and that streak spreading be minimized. The result is a downflow device, with larger gap width than is usual, warm inlet buffer solution, and protein injection slightly downstream of the start of the electrodes. If cooling is improved by increasing the thermal conductivity of the cooling walls, the gap width must be reduced and the buffer flow increased. The performance possible with perfect cooling walls is similar to that obtained in space because, in both cases, the limiting factor is not thermal convection but the high temperature generated at the mid-point between the cooling walls.