Zurich Instruments AG , Technoparkstrasse 1, 8005 Zurich, Switzerland.
Biomicrofluidics. 2015 Feb 11;9(1):014117. doi: 10.1063/1.4907896. eCollection 2015 Jan.
Label-free isolation of single cells is essential for the growing field of single-cell analysis. Here, we present a device which prints single living cells encapsulated in free-flying picoliter droplets. It combines inkjet printing and impedance flow cytometry. Droplet volume can be controlled in the range of 500 pl-800 pl by piezo actuator displacement. Two sets of parallel facing electrodes in a 50 μm × 55 μm channel are applied to measure the presence and velocity of a single cell in real-time. Polystyrene beads with <5% variation in diameter generated signal variations of 12%-17% coefficients of variation. Single bead efficiency (i.e., printing events with single beads vs. total number of printing events) was 73% ± 11% at a throughput of approximately 9 events/min. Viability of printed HeLa cells and human primary fibroblasts was demonstrated by culturing cells for at least eight days.
无标记的单细胞分离对于单细胞分析这一快速发展的领域至关重要。在这里，我们提出了一种设备，它可以打印封装在自由飞行的皮升级液滴中的单个活细胞。该设备结合了喷墨打印和阻抗流动细胞术。通过压电致动器的位移，可以将液滴体积控制在 500 pl-800 pl 范围内。在 50 μm×55 μm 的通道中设置两组平行的面对电极，可实时测量单个细胞的存在和速度。直径变化小于 5%的聚苯乙烯珠产生的信号变化为 12%-17%，变异系数。在大约 9 个事件/分钟的通量下，单个珠的效率（即，打印事件中有单个珠与总打印事件数之比）为 73%±11%。通过培养细胞至少 8 天，证明了打印的 HeLa 细胞和人原代成纤维细胞的活力。
