一种改进型单分子操纵装置及其应用

改进了单分子横向磁镊装置，可以直接用于观察单个DNA分子的伸长和扭转并随时更换样品池内的溶液，还可以同时操纵多个DNA分子，大大提高实验效率.此方法可以提供01到40pN范围的拉力，足以满足大部分单分子DNA实验的要求.用该装置实时观测到了DNA分子在拉力作用下的伸长以及在旋转磁场作用下的扭转，并成功地观察到了分子马达拉动DNA的动力学过程，从而验证了该装置的实用性. 关键词： 横向磁镊 单分子操纵 DNA拉伸 DNA扭转

An improved single molecule manipulation apparatus and its applications

We report an improvement to the lateral-magnetic-tweezers which can be used to stretch and twist DNA molecules, and to probe the interaction between DNA and proteins. The apparatus enables not only direct measurement of the extension and rotation of DNA but also easy refreshing of the buffer in the flow chamber. With this apparatus, the experimental efficiency can be greatly improved by manipulating several DNA molecules simultaneously. The force exerted on DNA molecules ranges from 0.1 to 40pN, satisfying the requirement of most single molecule experiments. To demonstrate the applicability of the apparatus, we measured the extension-force curve and the extension-rotation curve of DNA and studied the translocation of DNA by a motor protein. The results agree well with those reported in the literature.