Wang Chenyu, Liu Wenwen, Tan Manqing, Sun Hongbo, Yu Yude
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, People's Republic of China.
Biomicrofluidics. 2017 Jul 20;11(4):044106. doi: 10.1063/1.4995294. eCollection 2017 Jul.
Cellular heterogeneity represents a fundamental principle of cell biology for which a readily available single-cell research tool is urgently required. Here, we present a novel method combining cell-sized well arrays with sequential inkjet printing. Briefly, K562 cells with phosphate buffer saline buffer were captured at high efficiency (74.5%) in a cell-sized well as a "primary droplet" and sealed using fluorinated oil. Then, piezoelectric inkjet printing technology was adapted to precisely inject the cell lysis buffer and the fluorogenic substrate, fluorescein-di-β-D-galactopyranoside, as a "secondary droplet" to penetrate the sealing oil and fuse with the "primary droplet." We thereby successfully measured the intracellular β-galactosidase activity of K562 cells at the single-cell level. Our method allows, for the first time, the ability to simultaneously accommodate the high occupancy rate of single cells and sequential addition of reagents while retaining an open structure. We believe that the feasibility and flexibility of our method will enhance its use as a universal single-cell research tool as well as accelerate the adoption of inkjet printing in the study of cellular heterogeneity.
细胞异质性是细胞生物学的一个基本原理，为此迫切需要一种现成的单细胞研究工具。在此，我们提出一种将细胞大小的孔阵列与顺序喷墨打印相结合的新方法。简而言之，含有磷酸盐缓冲盐水缓冲液的K562细胞作为“初级液滴”以高效率（74.5%）捕获在细胞大小的孔中，并用氟化油密封。然后，采用压电喷墨打印技术精确注入细胞裂解缓冲液和荧光底物荧光素 - 二 - β - D - 吡喃半乳糖苷作为“次级液滴”，以穿透密封油并与“初级液滴”融合。我们从而成功地在单细胞水平上测量了K562细胞的细胞内β - 半乳糖苷酶活性。我们的方法首次实现了能够同时容纳单细胞的高占有率以及顺序添加试剂，同时保持开放结构。我们相信，我们方法的可行性和灵活性将提高其作为通用单细胞研究工具的用途，并加速喷墨打印在细胞异质性研究中的应用。
