Vimentin networks at tunable ion-concentration in microfluidic drops
Vimentin networks at tunable ion-concentration in microfluidic drops
复制标题
DOI：
10.1063/1.4705103
复制
发表时间：
2012-06-01
期刊：
影响因子：
3.2
通讯作者：
Koester, Sarah
中科院分区：
文献类型：
--
作者：
Dammann, Christian;Noeding, Bernd;Koester, Sarah
生物系统的结构和功能，例如细胞和蛋白质，强烈依赖于它们所处的化学环境。为了研究这种依赖关系，我们设计了一种基于聚二甲基硅氧烷的微流控装置，将生物系统包裹在皮升大小的液滴中。每个单独的水滴的内容都是以定义的方式调整的。作为我们方法的一个关键特征，单个化学成分是确定的，并与液滴含量相关。在我们的案例中，液滴内容物使用显微镜方法成像，而液滴被固定，以便进行长期研究。作为装置的一个应用，我们通过调节镁离子浓度从一滴到另一滴，定量研究了二价离子对波形蛋白中间丝网络的影响。通过这种方式，我们能够在几百滴中直接成像镁对带有荧光标记的蛋白质的影响。我们的研究表明，随着液滴中镁浓度的增加，网络的致密性变得更加明显。致密化程度具有不同的形貌特征，当镁浓度较低时(5~10 mm)，可以观察到自由波动的网络，而当镁浓度增加到16 mm时，则发展为完全聚集的网络。我们的方法展示了对生物系统中相互作用的系统研究如何受益于微流控方法的特殊可控性。(C)2012年美国物理研究所。[http://dx.doi.org/10.1063/1.4705103]
The structure and function of biological systems, for example, cells and proteins, depend strongly on their chemical environment. To investigate such dependence, we design a polydimethylsiloxane-based microfluidic device to encapsulate biological systems in picoliter-sized drops. The content of each individual drop is tuned in a defined manner. As a key feature of our method, the individual chemical composition is determined and related to the drop content. In our case, the drop content is imaged using microscopy methods, while the drops are immobilized to allow for long-time studies. As an application of our device, we study the influence of divalent ions on vimentin intermediate filament networks in a quantitative way by tuning the magnesium concentration from drop to drop. This way we are able to directly image the effect of magnesium on the fluorescently tagged protein in a few hundreds of drops. Our study shows that with increasing magnesium concentration in the drops, the compaction of the networks becomes more pronounced. The degree of compaction is characterized by different morphologies; freely fluctuating networks are observed at comparatively low magnesium concentrations of 5-10 mM, while with increasing magnesium concentration reaching 16 mM they develop into fully aggregated networks. Our approach demonstrates how a systematic study of interactions in biological systems can benefit from the exceptional controllability of microfluidic methods. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4705103]