Microplates-based rheometer for a single living cell
Microplates-based rheometer for a single living cell
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DOI：
10.1063/1.2202921
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发表时间：
2006-05-01
影响因子：
1.6
通讯作者：
Asnacios, A.
中科院分区：
文献类型：
--
作者：
Desprat, N.;Guiroy, A.;Asnacios, A.
我们开发了一种新的多功能微米级流变仪，它允许我们测量蠕变或松弛函数(时间分析)，以及确定单个活细胞的动态复模(频率分析)。在这种装置中，显微样品可以在两个平行的微板之间单向拉伸或压缩：一个是刚性的，另一个是柔性的。柔性微板被用作校准刚度的纳米牛顿力传感器，力简单地与板的挠度成正比。微板的原始设计使我们能够实现对施加到电池上的应变或应力进行有效的反馈控制。控制挠性板挠度的典型精度小于200 nm，我们能够施加从几个帕斯卡到数千帕斯卡的应力，精度优于2%。柔性板偏转的控制是通过安装在倒置显微镜的光管上的光敏探测器上的板尖端直接成像来实现的。因此，该检测原理适用于所有常见的显微镜，并且非常容易设置。除了在先前的工作中已经详细分析的蠕变函数之外，我们在这里报告了第一次测量松弛函数，以及对分离的活细胞的存储和损失动态模数[G(‘)(F)和G(’)(F)，f从0.02到10 Hz]的测量。最终，我们制造的流变仪并不局限于细胞拉伸。它也应该是一个强大的工具来研究微米级样品的流变性，如微凝胶或囊泡，以及执行剪切实验。(C)2006年美国物理研究所。
We developed a new versatile micron-scale rheometer allowing us to measure the creep or the relaxation function (time analysis), as well as to determine the dynamical complex modulus (frequency analysis) of a single living cell. In this setup, a microscopic sample can be stretched or compressed uniaxially between two parallel microplates: one rigid, the other flexible. The flexible microplate is used as a nanonewton force sensor of calibrated stiffness, the force being simply proportional to the plate deflection. An original design of the microplates allows us to achieve an efficient feedback control of either strain or stress applied to the cell. Controlling the flexible plate deflection with a typical precision of less than 200 nm, we are able to apply stresses ranging from a few pascals to thousands of pascals with a precision better than 2%. The control of the flexible plate deflexion is achieved by direct imaging of the plate tip on a photosensitive detector mounted on the phototube of an inverted microscope. Thus, the detection principle is suitable to all usual microscopes and very easy to set up. Beyond the creep function, already analyzed in detail in a previous work, we report here the first measurement of the relaxation function, as well as of the storage and the loss dynamic moduli [G(')(f) and G(')(f), f ranging from 0.02 to 10 Hz] for an isolated living cell. Eventually, the rheometer we built is not limited to cell stretching. It should also be a powerful tool to study the rheology of micron sized samples such as microgels or vesicles, as well as to perform shear experiments. (c) 2006 American Institute of Physics.