Imaging and Characterization of Single DNA Molecules Undergoing Electrophoresis. Measurements of Force and Torque on Single DNA Molecules

凝胶电泳过程中的超大DNA分子的动力学将使用之前NSF拨款开发的荧光显微镜进行研究。本研究的目的是：(L)描述DNA在稳态场和脉冲场中的运动；(2)确定在凝胶中捕获这些大分子的分子过程；(3)检测琼脂糖凝胶中“湖”和“超级湖”的存在；(4)改进DNA电泳的计算机模型。了解百万碱基DNA电泳的动力学可能会导致这项技术的改进，这对基因图谱研究至关重要。单个DNA分子的弹性和扭转特性也将通过将它们一端连接到顺磁珠上，另一端连接到显微镜载玻片上来研究。珠子将受到磁场的影响。为了了解这些分子在其自然环境中的行为，有必要对DNA的这些基本性质进行表征。

The dynamics of very large DNA molecules undergoing gel electrophoresis will be studied using a fluorescence microscope developed under a previous NSF grant. The objectives of this study are: (l) to characterize DNA motion in steady and pulsed fields; (2) to determine the molecular processes involved in the trapping of these large molecules in the gel; (3) to test for the existence of "lakes" and "super-lakes" in agarose gels; and (4) to improve the computer model of DNA electrophoresis. Understanding the dynamics of megabase DNA electrophoresis may lead to improvements in this technique which is vital to gene mapping studies. The elastic and torsional properties of single DNA molecules will also be studied by attaching them at one end to paramagnetic beads and at the other end to a microscope slide. The bead will be subjected to a magnetic field. A characterization of these basic properties of DNA is necessary for an understanding of the behaviour of these molecules in their natural milieu.