Electric cell-substrate impedance sensing or ECIS (a trademark of Applied BioPhysics Inc.) refers to a

non-invasive A medical procedure is defined as ''non-invasive'' when no break in the skin is created and there is no contact with the mucosa, or skin break, or internal body cavity beyond a natural or artificial body orifice. For example, deep palpation and pe ...

biophysical approach to monitor living animal

cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and ...

'', i.e. within a well-defined laboratory environment.Giaever & Keese: A morphological biosensor for mammalian cells, ''Nature'' 366(1993)591-2 In ECIS the cells are grown on the surface of small and planar gold-film

electrode An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). Electrodes are essential parts of batteries that can consist of a variety of materials ...

s, which are deposited on the bottom of a cell culture dish (

Petri dish A Petri dish (alternatively known as a Petri plate or cell-culture dish) is a shallow transparent lidded dish that biologists use to hold growth medium in which cells can be cultured,R. C. Dubey (2014): ''A Textbook Of Biotechnology For Class-X ...

). The AC impedance of the cell-covered electrode is then measured at one or several frequencies as a function of time. Due to the insulating properties of their membranes the cells behave like

dielectric In electromagnetism, a dielectric (or dielectric medium) is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the m ...

particles so that the impedance increases with increasing coverage of the electrode until a confluent (i.e. continuous) layer of cells is established. In confluent cell layers the measured impedance is mainly determined by the three-dimensional shape of the cells. If cell shape changes occur, the current pathways through and around the cell bodies change as well, leading to a corresponding increase or decrease of impedance. Thus, by recording time-resolved impedance measurements, cell shape changes can be followed in real time with sub-microscopic resolution and can be used for bioanalytic purposes. As the shape of animal cells responds very sensitively to alterations in

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...

as well as chemical, biological or physical stimuli, the ECIS technique is applied in various experimental settings in cell biological research laboratories. It can be used as a sensor in cytotoxicity studies,

drug development Drug development is the process of bringing a new pharmaceutical drug to the market once a lead compound has been identified through the process of drug discovery. It includes preclinical research on microorganisms and animals, filing for r ...

or as a non-invasive means to follow cell adhesion to ''in vitro'' surfaces.Wegener, Keese, Giaever: ECIS as a non-invasive means to follow the kinetics of cell spreading on artificial surfaces. ''Exp. Cell Res.'' 259(2000)158-166 Equipments based on the ECIS technique are also dedicated to monitor the chemokinetic activity of adherent cells spread on the electrode surface (micromotion) as well as their

chemotactic Chemotaxis (from '' chemo-'' + ''taxis'') is the movement of an organism or entity in response to a chemical stimulus. Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemical ...

activities in ECIS-based

wound healing Wound healing refers to a living organism's replacement of destroyed or damaged tissue by newly produced tissue. In undamaged skin, the epidermis (surface, epithelial layer) and dermis (deeper, connective layer) form a protective barrier aga ...

assays.

References

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References

See also