Label-free single-cell counting and characterization in the GHz-range

We demonstrate operation of a micropore based flow cytometer in the radio-frequency range. Apart from simply counting micron sized particles, such as cells, with close to nano-second resolution this counter offers the additional benefit of delivering insight into the intracellular environment. Such non-invasive screening of the cell's interior based on analysing amplitude and phase of the signal is helpful in characterizing the biological activity of cells. In detail we are using heterodyne mixing to demodulate the temporal impedance changes, which are induced by cells translocating through a micropore embedded in a radio-frequency circuit. This allows us to measure every amplitude and phase modulation induced by a translocation event. Herein, we compare the Jurkat cells (human T lymphocytes) recordings with a control group of polystyrene beads. As the cells are measured on a single cell level, the variations on the measured amplitude and phase signals are used, herein, to sense morphological cell changes in real time.