The Port-a-Patch is a one-cell-at-a-time system, which is surprisingly small for a complete patch clamp rig. Patch clamp recordings in the whole cell configuration, and single channel recordings in the cell attached configuration, can be performed with planar patch clamp chips. The Port-a-Patch is routinely provided with an EPC-10 amplifier from HEKA together with a computer and the software packages. Manual liquid-handling is combined with computer controlled suction supply for automated sealing and whole cell access. An optional Perfusion System and Temperature Control device is available.