Investigation of bacterial chemotaxis in flow-based microfluidic devices
Investigation of bacterial chemotaxis in flow-based microfluidic devices
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DOI：
10.1038/nprot.2010.18
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发表时间：
2010-01-01
期刊：
影响因子：
14.8
通讯作者：
Jayaraman, Arul
中科院分区：
文献类型：
--
作者：
Englert, Derek L.;Manson, Michael D.;Jayaraman, Arul
插入池和毛细管测定是测量引诱剂和驱避剂细菌趋化性的方便方法。然而，这些测定不提供迁移程度的定量信息，不适合调查驱避剂的出租车。在这里，我们描述了一个协议的流动为基础的微流体系统（μ流），以定量研究趋化性的浓度梯度的引诱剂和驱避剂。mu Flow装置使用扩散混合来产生浓度梯度，该浓度梯度在整个趋化性室和实验期间是稳定的。梯度可以具有任何期望的绝对浓度和梯度强度。表达GFP的细菌在进入趋化室时立即遇到稳定的浓度梯度，并且通过显微镜监测响应于梯度的迁移。不同的参数，影响的迁移的程度在mu流设备的准备的能动的细菌种群的制备，浓度梯度的强度和暴露的梯度的持续时间的影响进行了讨论的背景下，驱避剂的趋化性野生型大肠杆菌细胞在梯度的硫酸镍。微流控装置的制造需要1天，而制备运动细胞和进行趋化实验需要4-6小时才能完成。
The plug-in-pond and capillary assays are convenient methods for measuring attractant and repellent bacterial chemotaxis. However, these assays do not provide quantitative information on the extent of migration and are not well-suited for investigating repellent taxis. Here, we describe a protocol for a flow-based microfluidic system (mu Flow) to quantitatively investigate chemotaxis in response to concentration gradients of attractants and repellents. The mu Flow device uses diffusive mixing to generate concentration gradients that are stable throughout the chemotaxis chamber and for the duration of the experiment. The gradients may be of any desired absolute concentration and gradient strength. GFP-expressing bacteria immediately encounter a stable concentration gradient when they enter the chemotaxis chamber, and the migration in response to the gradient is monitored by microscopy. The effects of different parameters that influence the extent of migration in the mu Flow device-preparation of the motile bacterial population preparation, strength of the concentration gradient and duration of exposure to the gradient-are discussed in the context of repellent taxis of chemotactically wild-type Escherichia coli cells in a gradient of NiSO4. Fabrication of the microfluidic device takes 1 d while preparing motile cells and carrying out the chemotaxis experiment takes 4-6 h to complete.