A sensitive, versatile microfluidic assay for bacterial chemotaxis
A sensitive, versatile microfluidic assay for bacterial chemotaxis
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DOI：
10.1073/pnas.0931258100
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发表时间：
2003-04-29
影响因子：
11.1
通讯作者：
Manson, MD
中科院分区：
文献类型：
--
作者：
Mao, HB;Cremer, PS;Manson, MD
我们已经开发了一种用于细菌趋化性的微流体测定，其中通过层流中平行液流之间的扩散在微通道内建立化学效应物的梯度。随机运动和趋化反应L-天冬氨酸，L-丝氨酸，L-亮氨酸，镍2+的野生型和趋化突变株的大肠杆菌进行了测量。通过计数在22个出口端口中的每一个中积累的细胞来定量细胞的迁移。WT细胞对3.2 nM L-天冬氨酸（比标准毛细管测定中的检测限低三个数量级的浓度）的显著响应证明了测定的灵敏度。驱避剂的反应是强大的，很容易记录的引诱剂的反应。一个令人惊讶的发现是，L-亮氨酸在低浓度下被焦油感知为引诱剂，而在较高浓度下被Tsr感知为驱避剂。相对于现有的测定细菌策略反应的测定，该测定提供了上级的性能和便利性，并且其足够灵活以用于广泛的不同应用中。
We have developed a microfluidic assay for bacterial chemotaxis in which a gradient of chemoeffectors is established inside a microchannel via diffusion between parallel streams of liquid in laminar flow. The random motility and chemotactic responses to L-aspartate, L-serine, L-leucine, and Ni2+ of WT and chemotactic-mutant strains of Escherichia coli were measured. Migration of the cells was quantified by counting the cells accumulating in each of 22 outlet ports. The sensitivity of the assay is attested to by the significant response of WT cells to 3.2 nM L-aspartate, a concentration three orders of magnitude lower than the detection limit in the standard capillary assay. The response to repellents was as robust and easily recorded as the attractant response. A surprising discovery was that L-leucine is sensed by Tar as an attractant at low concentrations and by Tsr as a repellent at higher concentrations. This assay offers superior performance and convenience relative to the existing assays to measure bacterial tactic responses, and it is flexible enough to be used in a wide range of different applications.