Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius LT 10257, Lithuania.
Anal Chem. 2024 May 7;96(18):6898-6905. doi: 10.1021/acs.analchem.3c05243. Epub 2024 Apr 22.
High-throughput single-cell analysis typically relies on the isolation of cells of interest in separate compartments for subsequent phenotypic or genotypic characterization. Using microfluidics, this is achieved by isolating individual cells in microdroplets or microwells. However, due to cell-to-cell variability in size, shape, and density, the cell capture efficiencies may vary significantly. This variability can negatively impact the measurements and introduce undesirable artifacts when trying to isolate and characterize heterogeneous cell populations. In this study, we show that single-cell isolation biases in microfluidics can be circumvented by increasing the viscosity of fluids in which cells are dispersed. At a viscosity of 40-50 cP (cP), the cell sedimentation is effectively reduced, resulting in a steady cell flow inside the microfluidics chip and consistent encapsulation in water-in-oil droplets over extended periods of time. This approach allows nearly all cells in a sample to be isolated with the same efficiency, irrespective of their type. Our results show that increased fluid viscosity, rather than cell-adjusted density, provides a more reliable approach to mitigate single-cell isolation biases.
高通量单细胞分析通常依赖于将感兴趣的细胞在单独的隔室中分离出来，以便随后进行表型或基因型表征。使用微流控技术，可以通过在微滴或微池中分离单个细胞来实现这一点。然而，由于细胞间大小、形状和密度的差异，细胞捕获效率可能会有很大差异。这种可变性会对测量结果产生负面影响，并在尝试分离和表征异质细胞群体时引入不必要的假象。在这项研究中，我们表明，通过增加细胞分散在其中的流体的粘度，可以避免微流控中单细胞分离的偏倚。在粘度为 40-50 cP（厘泊）时，细胞沉降会被有效降低，从而导致微流控芯片内的细胞稳定流动，并在较长时间内保持油包水微滴中的一致封装。这种方法可以以相同的效率分离样品中的几乎所有细胞，而与它们的类型无关。我们的结果表明，增加流体粘度而不是细胞调整密度，提供了一种更可靠的方法来减轻单细胞分离的偏倚。
