title: Real-time measurement of PMA-induced cellular alterations by microelectrode array-based impedance spectroscopy.
abstract: For a feasible and cost-effective impedance measurement of cellular alterations in real-time, we combined commercially available microelectrode arrays (MEAs), consisting of 60 microelectrodes, with a conventional impedance analyzer. For proof of principle, a breast carcinoma cell line (MCF-7) was cultured on MEAs, and cellular alterations were measured by impedance spectroscopy at a frequency ranging from 10 Hz to 1 MHz. Cells were stimulated with phorbol 12-myristate 13-acetate (PMA) at different concentrations to activate protein kinase C (PKC)-mediated extra- and intracellular changes. By addition of 0.03 microM PMA, an increase of the relative impedance (Z(rel)) was observed after 10 min with a maximum at 1 kHz. Moreover a gradual elevation of the impedance was measured 60 min after stimulation with PMA. If 0.3 microM PMA was applied, the maximal amplitude of the relative impedance after 60 min shifted from 1 kHz (0.03 microM PMA) to 150 Hz. Subsequently, the impedance was further increased up to 90 min after PMA application, after which the impedance reduced after 240 min. Since we could use MEAs for at least 10 times without affecting the sensitivity, our study revealed that commercially available MEAs comprising nanocolumnar titanium nitrite electrodes are suitable microstructures for a highly reproducible and cost-effective multisite measurement of intracellular processes by impedance spectroscopy.
authors.affiliation: Center for Biotechnology and Biomedicine, Division of Molecular Biological-Biochemical Processing Technology, Faculty of Biosciences, Pharmacy and Psychology, University of Leipzig, Leipzig, Germany. andree.rothermel@bbz.uni-leipzig.de
authors.forename: Andrée
authors.initials: A
authors.lastname: Rothermel
authors.forename: Matthias
authors.initials: M
authors.lastname: Nieber
authors.forename: Jana
authors.initials: J
authors.lastname: Müller
authors.forename: Peter
authors.initials: P
authors.lastname: Wolf
authors.forename: Maik
authors.initials: M
authors.lastname: Schmidt
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Robitzki
mesh_terms: D000497:Alloys / Q000737:chemistry; D001943:Breast Neoplasms / Q000473:pathology; D045744:Cell Line, Tumor; D017097:Electric Impedance; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005240:Feasibility Studies; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006801:Humans; D007150:Immunohistochemistry; D008839:Microelectrodes; D008856:Microscopy, Fluorescence; D036103:Nanotechnology / Q000379:methods; D009532:Nickel / Q000737:chemistry; D020411:Oligonucleotide Array Sequence Analysis; D013057:Spectrum Analysis / Q000379:methods*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014025:Titanium / Q000737:chemistry
chemical_list: D000497:Alloys; D005456:Fluorescent Dyes; D009532:Nickel; D014025:Titanium; D016650:Fluorescein-5-isothiocyanate; D013755:Tetradecanoylphorbol Acetate