The twin-trough chamber is the simplest of the developing chambers. It consists of a standard rectangular developing tank with a raised, wedge-shaped bottom. The wedged bottom divides the tank into two compartments, so that it is possible to either develop two plates simultaneously, or to use one compartment to precondition the sorbent layer prior to development. The plate is placed in one compartment and the mobile phase or the conditioning solvent in the other. The mobile phase can be added directly to the plate compartment or, when the mobile phase is first used for conditioning, the chamber can be tilted to allow the transfer of solvent into the compartment for development. To facilitate more rapid and uniform saturation of the vapor space in the chamber, its inner walls are usually lined with filter paper in contact with the mobile phase or conditioning solvent. A useful feature of the twin-trough camber is its lower solvent consumption (approximately 10 ml) compared with flat-bottomed chambers of a similar size. The twin-trough chamber is widely used for routine quality control applications.