Ultrasonically-Guided Flow Focusing Generates Precise Emulsion Droplets for High-Throughput Single Cell Analyses. Homo sapiens

We previously we outlined a new emulsion-based workflow for the rapid and effective analysis of paired heavy:light antibody sequencing from > 5 million single human B cells per experiment. The systems were shown to be highly effective and accurate, with some acceptable variation in droplet sizes (1, 2). For broader single-cell applications, we sought to achieve enhanced control of droplet sizes and thus control various critical features of single-cell reactions including the concentration of cells per droplet and the availability of reactants (e.g. magnetic beads, total reaction volume, enzyme quantities, etc.). Our improved instrument rapidly produces tunable droplet sizes that permit enhanced optimization of single-cell reactions in bioengineering and biotechnology. By reducing the emulsion size variability, this enhances uniformity for increased control of emulsion contents and can reduce inherent bias in systems such as the results from PCR amplification in polydisperse droplets. Precise control of droplet size can also enhance reagent efficiency by minimizing droplet size and reagent volumes as needed. The simplicity of the device assembly and operation, the comparatively large volumetric flow rates, and our ability to carry out high-throughput analysis of millions of individual mammalian cells in a massively parallel manner makes our emulsion microfluidics platform an effective new single-cell analysis tool to accelerate the study of single cell behavior in modern biotechnology.1. DeKosky, B.J., et al., In-depth determination and analysis of the human paired heavy- and light-chain antibody repertoire. Nature Medicine, 2014. 21: p. 86.2. McDaniel, J.R., et al., Ultra-high-throughput sequencing of the immune receptor repertoire from millions of lymphocytes. Nature Protocols, 2016. 11: p. 429.