Micromotion of mammalian cells measured electrically.
Motility is a fundamental property of mammalian cells that normally is observed in tissue culture by time lapse microscopy where resolution is limited by the wavelength of light. This paper examines a powerful electrical technique by which cell motion is quantitatively measured at the nanometer level. In this method, the cells are cultured on small evaporated gold electrodes carrying weak ac currents. A large change in the measured electrical impedance of the electrodes is observed when cells attach and spread on these electrodes. When the impedance is tracked as a function of time, fluctuations are observed that are a direct measure of cell motion. Surprisingly, these fluctuations continue even when the cell layer becomes confluent. By comparing the measured impedance with a theoretical model, it is clear that under these circumstances the average motions of the cell layer of 1 nm can be inferred from the measurements. We refer to this aspect of cell motility as micromotion.
Giaever
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School of Science, Rensselaer Polytechnic Institute, Troy, NY 12180-3590.
Keese
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CR
D002460:Cell Line; D002465:Cell Movement; D046508:Culture Techniques / Q000295:instrumentation / Q000379:methods; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods; D005347:Fibroblasts / Q000502:physiology; D006801:Humans; D008433:Mathematics; D008962:Models, Theoretical