The cellZscope is a device measuring the impedance of barrier-forming cell cultures grown on permeable membranes. The cellZscope measures and records the ohmic resistance (TEER, transepithelial / -endothelial resistance) and capacitance (Ccl) of the cell layers, and allows automated, long-term monitoring experiments without intervention. cellZscope is optimized for use with 6-, 12- or 24-well type inserts; and is fully compatible with inserts from different manufacturers. A direct correlation exists between the permeability of a cell layer and its resistance, the transepithelial /-endothelial electric resistance (TEER): tight cell layers exhibit high electric resistance, and high permeability correlates with low electric resistance.

The TEER measured across a cell layer is a highly qualified parameter for quantifying leak tightness of barrier forming tissue. The cellZscope measures and records the TEER of barrier forming cells to monitor the establishment or modulation of barrier-forming cell-to-cell contacts. The cell module is placed inside a standard incubator while the external controller is connected to a computer running the cZs-software. The device is ideally suited for studying the influence of substances such as drugs, toxins etc. on the barrier function of cell layers.