Disposable Coded Low Signal-Noise Ratio Single Cell Impedance Cytometry

S. Emaminejad, M. Javanmard, R.W. Dutton, R.W. Davis
Stanford Genome Technology Center, US

Keywords: impedance cytometry, coding, microfluidics, disposable device

Summary:

We envision a disposable device that can be inserted onto a Printed Circuit board (PCB) which has a non-disposable, yet inexpensive, electronic reading apparatus. This significantly reduces the manufacturing costs (5 cents per consumable device in retail price, and the instrumentation cost of $5), making it suitable for low resource settings, such as point-of-care testing in the developing countries. In this work, we demonstrated a novel and cost-effective approach to implement a disposable coded microfluidic flow-through impedance cytometer. Conventional methods for single cell impedance cytometry use microfabricated electrodes in direct contact with the buffer to measure changes of its electrical impedance when cells pass through the applied electric field. However, this approach requires expensive microfabrication of electrodes, and also, the fabricated electrodes cannot be reused without thorough and time-consuming cleaning process. Here, we introduced a simple approach to allow for single cell impedance cytometry using electrodes that can be reused, without the need for microfabrication of the electrodes. Furthermore, we used microchannels with corrugated sidewalls to code their widths, which improves the robustness of cell counting by reducing the detection error.