微芯片上加速流动导致的单链 DNA 分子拉伸。

Stretching of single DNA molecules caused by accelerating flow on a microchip.

机构信息

Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395 Japan.

Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan.

出版信息

J Chem Phys. 2018 Oct 28;149(16):165101. doi: 10.1063/1.5040564.

DOI:10.1063/1.5040564

PMID:30384753

Abstract

DNA elongation induced by fluidic stress was investigated on a microfluidic chip composed of a large inlet pool and a narrow channel. Through single-DNA observation with fluorescence microscopy, the manner of stretching of individual T4 DNA molecules (166 kbp) was monitored near the area of accelerating flow with narrowing streamlines. The results showed that the DNA long-axis length increased in a sigmoidal manner depending on the magnitude of flow acceleration, or shear, along the DNA chain. To elucidate the physical mechanism of DNA elongation, we performed a theoretical study by adopting a model of a coarse-grained nonlinear elastic polymer chain elongated by shear stress due to acceleration flow along the chain direction.

摘要

在由大入口池和狭窄通道组成的微流控芯片上研究了流体应力诱导的 DNA 延伸。通过荧光显微镜对单个 DNA 的观察，在流线变窄的加速流区域附近监测了单个 T4 DNA 分子（166 kbp）的拉伸方式。结果表明，DNA 长轴长度随流动加速度（或剪切）沿 DNA 链的大小呈类正弦方式增加。为了阐明 DNA 伸长的物理机制，我们通过采用沿链方向因加速流引起的剪切应力伸长的粗粒非线性弹性聚合物链模型进行了理论研究。