Isolation of single motile cells using a high-speed picoliter pipette

Isolation of single cells is a fundamental technique for single-cell analyses. High resolution of controlled volume is required to isolate the target cell from a cell group with tiny medium of single-cell level. Furthermore, the speed of isolation is also an important requirement to capture a motile cell. To achieve cell isolation with high resolution at high speed, we present a high-speed picoliter pipette as an isolation device, which is driven by a piezoelectric actuator. We evaluated performances of the developed picoliter pipette. The results showed a high-resolution and high-speed response of 0.42 pL and 3.9 ms, respectively. In addition, we applied the picoliter pipette to isolate the Euglena gracilis (E. gracilis) cell which was a motile cell. Utilizing the fast response of developed picoliter pipette, we succeeded in picking up a swimming single E. gracilis cell. After the picking up, we isolated the picked cells into other culture dish individually. We evaluated viability of the isolated E. gracilis cells, and 99.1 % (total: 110 cells) of the cells showed motility and division ability. From these results, we achieved the high-speed picoliter pipetting for single-cell isolation.