Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland.
Lab Chip. 2012 Oct 21;12(20):3995-4002. doi: 10.1039/c2lc40540g.
We demonstrate an integrated system for rapid and automated generation of multiple, chemically distinct populations of 10(3)-10(4) sub-nanoliter droplets. Generation of these 'libraries of droplets' proceeds in the following automated steps: i) generation of a sequence of micro-liter droplets of individually predetermined composition, ii) injection of these 'parental' droplets onto a chip, iii) transition from a mm- to a μm-scale of the channels and splitting each of the parental drops with a flow-focusing module into thousands of tightly monodisperse daughter drops and iv) separation of such formed homogeneous populations with plugs of a third immiscible fluid. This method is compatible both with aspiration of microliter portions of liquid from a 96-well plate with a robotic station and with automated microfluidic systems that generate (μL) droplets of preprogrammed compositions. The system that we present bridges the techniques that provide elasticity of protocols executed on microliter droplets with the techniques for high-throughput screening of small (~pL, ~nL) droplet libraries. The method that we describe can be useful in exploiting the synergy between the ability to rapidly screen distinct chemical environments and to perform high-throughput studies of single cells or molecules and in digital droplet PCR systems.
我们展示了一种集成系统，用于快速自动生成多个具有不同化学性质的~10(3)-10(4)亚纳升级别的微滴群体。这些“微滴文库”的生成按照以下自动化步骤进行：i）生成一系列具有预定组成的微升级别微滴，ii）将这些“母液”微滴注入芯片，iii）将通道从毫米尺度转换为微米尺度，并使用流聚焦模块将每个母液微滴分裂成数千个紧密单分散的子液滴，iv）使用第三不相容流体的塞子分离形成的均匀群体。这种方法与使用机器人工作站从 96 孔板中吸取微升级别液体部分的方法以及生成预编程组成的（μL）级别的微升级别液滴的自动化微流控系统兼容。我们提出的系统结合了在微升级别液滴上执行协议的灵活性技术以及对小（pL，nL）级别的微滴文库进行高通量筛选的技术。我们描述的方法可用于利用快速筛选不同化学环境的能力和对单细胞或单分子进行高通量研究以及数字液滴 PCR 系统之间的协同作用。
