Microchip-based impedance flow cell analyzer

Label-free and rapid analysis of a large-scale cells is essential for single-cell analysis and the point-of-care testing (POCT). We demonstrated a microchip-based impedance flow cytometer for cell identification and counting in single-cell level without labelling. Cells were focused to sequentially flow through a straight channel in a disposable chip. One pair of coplanar sensing electrodes underneath the channel was driven by an alternating current (AC) signal at given frequency and phase for continues impedance monitoring. Pulses of impedance was captured by lock-in amplifiers when cells passed the electrodes. The impedance signals and micrographs of leukocytes, RBCs, HeLa and Jurkat cells etc. passing a channel 20 μm in width with 0.1 m/s flow rate were obtained to provide the information of cell volume and cytoplasmic conductivity.