An electrical impedance method to continuously monitor morphology and motion of cells in culture

Summary form only given as follows: Great advances have been made in quantifying biochemical and physiological activities in cultured cells. It has, however been difficult to quantify changes of cell morphology. A method has now been developed that can continuously and non-invasively track morphological changes of adherent cells and provide data from both sparse and confluent cultures. In electric cell-substrate impedance sensing (ECIS), cells are cultured on small (0.001 cm² ) gold film electrodes whose impedance is measured with a 1 micro amp current, generally at 4,000 Hz; normal tissue culture medium serves as the electrolyte. When cells attach and spread on these electrodes, their essentially insulating membranes constrain the current and force it to flow beneath and between the cells. This results in large impedance changes. Furthermore, alterations in cell morphology gives rise to variations in impedance that can be numerically analyzed to report levels of cell motility and, indirectly, cell metabolism. The approach is exceedingly sensitive and is capable of detecting changes in cell morphology on the order of nanometers, well below the resolution of an optical microscope