Online impedance monitoring of yeast cell culture behaviors

Online impedance monitoring of cell suspensions can be performed with integrated microelectrode array in microfluidic devices. However, its accuracy is affected by the formation of cell aggregates on the surface of the electrode array. To make this technical more reliable, we deposited a thin film of agarose which is highly permeable to soluble ions on the electrodes. The growth behavior of yeast cells in YPD medium was studied for more than 24 h and the recorded impedance spectra were used to determinate the cell metabolism induced changes of the medium resistance and the double layer capacitance as a function of time. Our results showed a much more important variation of the double layer capacitance, indicating the importance of online monitoring at low frequencies.