School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology, 100 Banyeon-ri, Ulsan 689-798, Korea.
Anal Chem. 2010 Nov 15;82(22):9401-9. doi: 10.1021/ac102022q. Epub 2010 Oct 27.
We present a diffusion-driven and long-range concentration gradient generator that uses hydrogel as a porous membrane to prevent convection flows but allow the diffusion of cell signaling molecules for the study of bacterial chemotaxis in a microfluidic device. Using this device, we characterized the critical concentrations associated with the chemotactic responses of cells that initially created a population band and then migrated in bands in the presence of multiconcentration gradients. In addition, this device can be used to study the preferential chemotaxis of bacterial cells toward different carbon sources: glucose, galactose, and mannose were preferred over arabinose and xylose, in this order. This was possible since the device is able to simultaneously produce long-range concentration gradients of different chemicals as well. The method presented in this study is easy to perform and the device is cheap to fabricate, so that we believe that these characteristics not only make this device a very useful tool to study the chemotaxis of various, motile microorganisms but also permit parallel experimentation and reduce the time and effort needed in characterizing bacterial responses to various chemicals.
我们提出了一种扩散驱动的长程浓度梯度发生器，该发生器使用水凝胶作为多孔膜，以防止对流流动，但允许细胞信号分子扩散，从而在微流控装置中研究细菌的趋化性。使用该装置，我们表征了与细胞趋化反应相关的临界浓度，这些细胞最初形成了一个群体带，然后在多浓度梯度存在下以带的形式迁移。此外，该装置可用于研究细菌细胞对不同碳源的优先趋化性：葡萄糖、半乳糖和甘露糖优先于阿拉伯糖和木糖，依此顺序。之所以如此，是因为该装置还能够同时产生不同化学物质的长程浓度梯度。本研究中提出的方法易于实施，且该装置的制造成本低廉，因此我们相信，这些特性不仅使该装置成为研究各种运动微生物趋化性的非常有用的工具，而且还允许并行实验，并减少表征细菌对各种化学物质反应所需的时间和精力。
