Department of Biomedical Engineering, Boston University, 44 Cummington St., Boston, MA 02215, USA.
Lab Chip. 2011 Mar 21;11(6):1089-95. doi: 10.1039/c0lc00362j. Epub 2011 Feb 4.
Monitoring the real-time behavior of spatial arrays of single living bacteria cells is only achieved with much experimental difficulty due to the small size and mobility of the cells. To address this problem, we have designed and constructed a simple microfluidic device capable of trapping single bacteria cells in spatially well-defined locations without the use of chemical surface treatments. The device exploits hydrodynamics to slow down and trap cells flowing near a narrow aperture. We have modeled this system numerically by approximating the motion of Escherichia coli cells as rigid 3-D ellipsoids. The numerical predictions for the speed and efficiency of trapping were tested by fabricating the devices and imaging GFP expressing E. coli at a high spatio-temporal resolution. We find that our numerical simulations agree well with the actual cell flow for varying trap geometries. The trapped cells are optically accessible, and combined with our ability to predict their spatial location we demonstrate the ease of this method for monitoring multiple single cells over a time course. The simplicity of the design, inexpensive materials and straightforward fabrication make it an accessible tool for any systems biology laboratory.
由于细胞体积小且具有流动性，实时监测单细胞在空间上的行为仅在具有很大实验难度的条件下才能实现。为了解决这个问题，我们设计并构建了一种简单的微流控装置，无需使用化学表面处理即可将单个细菌细胞固定在空间上确定的位置。该装置利用流体动力学在狭窄的孔径附近减慢和捕获细胞的流动。我们通过将大肠杆菌细胞的运动近似为刚性 3-D 椭球体来对该系统进行数值模拟。通过制造设备并以高时空分辨率对表达 GFP 的大肠杆菌进行成像，我们对捕获速度和效率的数值预测进行了测试。我们发现，对于不同的捕获几何形状，我们的数值模拟与实际的细胞流动非常吻合。捕获的细胞在光学上是可访问的，并且结合我们预测其空间位置的能力，我们证明了该方法易于在一段时间内监测多个单细胞。该设计简单、材料廉价且制造过程简单，使其成为任何系统生物学实验室都可使用的一种实用工具。
