Liu Chao, Li Ying, Li Yiwei, Chen Peng, Feng Xiaojun, Du Wei, Liu Bi-Feng
Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
Talanta. 2016;149:237-243. doi: 10.1016/j.talanta.2015.11.036. Epub 2015 Nov 17.
Rapid mixing of highly viscous solutions is a great challenge, which helps to analyze the reaction kinetics in viscous liquid phase, particularly to discover the folding kinetics of macromolecules under molecular crowding conditions mimicking the conditions inside cells. Here, we demonstrated a novel microfluidic mixer based on Dean flows with three-dimensional (3D) microchannel configuration for fast mixing of high-viscosity fluids. The main structure contained three consecutive subunits, each consisting of a "U"-type channel followed by a chamber with different width and height. Thus, the two solutions injected from the two inlets would undergo a mixing in the first "U"-type channel due to the Dean flow effect, and simultaneous vortices expansions in both horizontal and vertical directions in the following chamber. Numerical simulations and experimental characterizations confirmed that the micromixer could achieve a mixing time of 122.4μs for solutions with viscosities about 33.6 times that of pure water. It was the fastest micromixer for high viscosity solutions compared with previous reports. With this highly efficient 3D microfluidic mixer, we further characterized the early folding kinetics of human telomere G-quadruplex under molecular crowding conditions, and unravelled a new folding process within 550μs.
高粘性溶液的快速混合是一项巨大挑战，这有助于分析粘性液相中的反应动力学，特别是在模拟细胞内条件的分子拥挤环境下发现大分子的折叠动力学。在此，我们展示了一种基于迪恩流的新型微流体混合器，其具有三维（3D）微通道结构，用于快速混合高粘性流体。主要结构包含三个连续的亚单元，每个亚单元由一个“U”型通道和一个宽度与高度不同的腔室组成。因此，从两个入口注入的两种溶液会由于迪恩流效应在第一个“U”型通道中发生混合，并在随后的腔室中在水平和垂直方向同时产生涡旋扩展。数值模拟和实验表征证实，对于粘度约为纯水33.6倍的溶液，该微混合器可实现122.4μs的混合时间。与先前的报道相比，它是用于高粘性溶液的最快微混合器。利用这种高效的3D微流体混合器，我们进一步表征了分子拥挤条件下人端粒G-四链体的早期折叠动力学，并揭示了550μs内的新折叠过程。
