High pressure electrophoresis in narrow bore glass tubes: One‐ and two‐dimensional separations of protein subunits

A mini‐gel tube electrophoresis apparatus that is easily constructed and simple to operate has been developed. The system can be accommodated in standard commercially available high pressure tubing, and has been tested at up to 200 MPa. The narrow diameter of the glass tubes allows rapid and efficient dissipation of heat. Adequate buffer capacity is maintained in the low volume anode reservoir by increasing the concentration of the buffer. Analytical separations can be achieved in short times with high resolution. After the electrophoresis has been carried out at elevated pressure, the gel can easily be extruded from the tube and loaded onto a standard slab gel for a second‐dimensional run at atmospheric pressure. We illustrate the application of this apparatus with the high pressure gel electrophoresis separation and subsequent identification of the constituent subunits of E. coli RNA polymerase.