TEER – “Monitoring cell – attachment and tight junctions in the same assay”

The numerous different cell types in the human body are greatly specialized and often require a conjunctive action of a population of cells, for example in tissues. Cells are interconnected via cell junctions, multiprotein complexes found in the cell membrane of animal cells, and such cell junctions allow for a mechanical, chemical or electrical transmission of signals. These junctions can be subdivided into (I) tight junctions, (II) anchoring junctions or (III) gap junctions. Defects in cell–cell junctions give rise to a wide range of tissue abnormalities that disrupt homeostasis and are common in genetic abnormalities and cancers (1). The so-called tight junctions form the barrier in endothelial and epithelial cells. Classical transepithelial electrical resistance measurements are performed using microelectrodes, where trans- and para-cellular conductivities can be calculated (2).
Here the cells are grown on a porous filter membrane which is placed between two fluid compartments. Flux of solutes from one compartment to the other must pass the interfacial cell
layer then, and this is determined by the functional properties of the tight junctions.