Sheathless microflow cytometer utilizing two bulk standing acoustic waves.

In recent years, microflow cytometry has become a popular research field because of its potential to provide low-cost and disposable chips for complex cell analyses. Herein, we demonstrate a sheathless microflow cytometer which integrates a bulk standing acoustic wave based microchip capable of three dimensional cell focusing. Flow cytometry was successfully demonstrated using this system with a coefficient of variation (CV) of 2.16% with standard calibration beads. The sensitivities calibrated by rainbow beads are 518 MEFL in fluorescein Isothiocyanate (FITC) channel and 264 MEPE in P-phycoerythrin (PE) channels, respectively. The linearities are more than 99% in both channels. The capability of the proposed microflow cytometer is further demonstrated by immunologically labeled leukocytes differentiation in blood. This acoustic-based microflow cytometer did not require any sheath flows or complex structures and can be mass produced. Because of the simple fluid channel, the chip can be easily made pipeless, disposable for applications requiring no cross contamination. Moreover, with the gentle and bio-compatible acoustic waves used, this technique is expected to maintain the viability of cells and other bioparticles.