Horizontal electrophoresis or isoelectric focusing apparatus and method of using same

A method for separating a starting species into separate fractions by electrophoresis or isoelectric focusing, in an elongated, horizontal vessel having horizontally spaced-apart electrodes therein, said vessel having an unobstructed zone along its bottom and having a multiplicity of upright, generally parallel, horizontally spaced-apart partitions defining a multiplicity of separate compartments above said zone, which comprises the steps of:

• depositing a quantity of said starting species carried in a liquid electrophoresis or isoelectric focusing medium in said zone to form a stationary liquid layer in said zone which layer is in contact with said electrodes;
• then applying an electrophoresis or isoelectric focusing potential across said electrodes for a period of time effective to cause said species to migrate electrophoretically in a horizontal direction in said layer to separate said species into fractions which are horizontally displaced from one another in a direction lengthwise of said vessel;
• then turning said vessel about its horizontal longitudinal axis whereby to cause said layer to flow into said compartments so that the respective fractions become separated from each other and are located in different ones of said compartments.