Evaluation of a capillary measuring system for the characterisation of small tissue samples by impedance spectroscopy at higher frequencies

For the gentle and non-destructive characterisation of small tissue samples, non-invasive methods are required for biotechnological applications and medical diagnostics. One approach is the characterisation of small tissue samples by impedance spectroscopy using a measuring capillary. In this paper, the applicability of a capillary measuring system to record the impedance of a biological sample over a wide frequency range is evaluated using a suspension of human breast adenocarcinoma cells (MCF-7). Impedance spectra over a frequency range 1 Hz to 1.1 GHz were recorded. To describe the electrical properties of the cell suspensions, we use an equivalent circuit model containing advanced RC-elements. Changes of plasma membrane integrity of suspended cells were detectable