Diao Zhidian, Wang Xixian, Zhang Jiaping, Ge Anle, Xu Teng, Kan Lingyan, Li Yuandong, Ji Yuetong, Jing Xiaoyan, Xu Jian, Ma Bo
Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China.
Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China.
Biosens Bioelectron. 2023 Nov 15;240:115639. doi: 10.1016/j.bios.2023.115639. Epub 2023 Aug 25.
Static droplet array (SDA) is a pivotal tool for high-capacity screening assays, yet extraction and collection the target droplets that contain unique analytes or cells from the SDA remains one major technical bottleneck that limits its broader application. Here we present an optical-based on-demand droplet release (OODR) system by incorporating a 1064 nm laser-responsive indium tin oxide (ITO) layer into a chamber array-based droplet microfluidic chip. By focusing the 1064 nm laser onto the ITO layer, microbubbles can be created via local heating to selectively push-out the droplets from the chamber. Then the released droplet is readily exported in a one-droplet-one-tube (ODOT) manner by the inherent capillary force into pipette tip. Releasing of the droplets containing fluorescein sodium demonstrated ∼100% successful rate (9 out of 6400 droplets were successfully released) and low residual (only ∼5% of the droplet volume remains in the chamber). White or fluorescence image-based releasing of single-cell-droplets directly after cell loading or multi-cells-droplets derived from on-chip single-cell cultivation for both E. coli and yeast cells further demonstrated the wide applicability of OODR. The present system is user-friendly and has the potential to be applied in various high-throughput screening assays, including single molecule/cell analysis, drug screening, and phenotype-based cell sorting.
静态液滴阵列（SDA）是用于高容量筛选分析的关键工具，然而从SDA中提取和收集包含独特分析物或细胞的目标液滴仍然是限制其更广泛应用的一个主要技术瓶颈。在此，我们通过将1064 nm激光响应氧化铟锡（ITO）层整合到基于腔室阵列的液滴微流控芯片中，提出了一种基于光学的按需液滴释放（OODR）系统。通过将1064 nm激光聚焦到ITO层上，可通过局部加热产生微气泡，以选择性地将液滴从腔室中推出。然后，释放的液滴通过固有的毛细作用力以一滴一管（ODOT）的方式轻松导出到移液器吸头中。含有荧光素钠的液滴释放成功率约为100%（6400个液滴中有9个成功释放），且残留量低（腔室中仅残留约5%的液滴体积）。在加载细胞后直接基于白色或荧光图像释放单细胞液滴，或基于芯片上单细胞培养的大肠杆菌和酵母细胞的多细胞液滴，进一步证明了OODR的广泛适用性。本系统用户友好，有潜力应用于各种高通量筛选分析，包括单分子/细胞分析、药物筛选和基于表型的细胞分选。
