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Automated dielectric single cell spectroscopy - temperature dependence of electrorotation

: Mietchen, D.; Schnelle, T.; Müller, T.; Hagedorn, R.; Fuhr, G.


Journal of Physics. D. Applied Physics 35 (2002), pp.1258-1270
ISSN: 0022-3727
ISSN: 1361-6463
Journal Article
Fraunhofer IBMT ()

A theoretical framework is presented which allows, for the first time, quantitative statements about the temperature dependence of electrorotation (ER): while temperature changes in physiological ranges do not significantly alter the overall shape of the spectrum, all of the characteristic points of the spectra do shift, to varying extends, in both their field frequency and amplitude of rotation. To experimentally verify these predictions, we developed a device which allows for autonomous detection of rotation speed. It is based on the pinhole technique known as MOSPAD [1] but differs in its higher degree of automation, more robust algorithms for signal analysis, and the possible use of an adaptable virtual mask in the video-RAM instead of the solid one in the optical path. Our results are in good agreement with theory and suggest previous ER data without temperature control should be reconsidered. We describe conditions under which physical and physiological effects of temperature in and on cells can be distinguished. Moreover, we broaden the applications of ER from the traditional determination of (rather static) cellular properties to kinetics of cellular processes, to the impact of optical tweezers on the temperature of cells in their focus, or to resonance characteristics of electrode chambers.