基于液滴蒸发分子梳技术的DNA分子拉伸及其图案动力学机制研究

发布时间：2018-04-25 21:10

本文选题：分子梳 + 缓冲液浓度　；参考：《西北大学》2017年硕士论文

【摘要】：针对溶液中的单分子DNA的可视化和操纵技术,有助于研究DNA分子的物化性质及其应用,加深了人类对生命基元的探索和对生命基本原理的认识。另外,基于单分子DNA的有序2D/3D结构,可以作为微纳传感器件的构成单元,开展微检测技术在生命科学领域的研究。分子梳技术是一种简单高效的、借助界面力拉伸操纵处于溶液中的DNA分子的技术。本文结合高分辨荧光成像系统和高精度接触角分析系统,研究了在液滴蒸发分子梳法中,缓冲液和DNA分子浓度对DNA液滴蒸发和DNA分子拉伸结果的影响,以及DNA蒸发形成的自组装图案。主要研究内容如下:首先,利用液滴蒸发法在聚甲基丙烯酸甲酯(PMMA)表面实现了对DNA分子的完全拉伸操纵。用高分辨荧光成像显微技术研究了 DNA分子在蒸发液滴内的定向移动,以及缓冲液浓度、溶液酸碱性、基底平整度与疏水性对DNA拉伸结果的影响。其次,利用高精度接触角分析系统研究了在不同缓冲液和DNA分子浓度下,DNA液滴的动态蒸发过程。实验发现,在DNA液滴蒸发过程中存在两种关键的蒸发模式:常接触角模式和常接触面积模式,并且这两种模式均受到缓冲液和DNA分子浓度的影响。其中,常接触角模式只存在于低浓度下,随着浓度升高此模式逐渐被混合模式所取代。常接触角模式的存在有利于实现DNA分子均匀拉伸。常接触面积模式在各种浓度普遍存在,在高浓度下,常接触面积模式持续时间更长,在这种情况下,拉伸的DNA分子容易形成一种环状分布图案。通过实验和理论分析,可以将DNA环状图案的形成归因于“咖啡环”效应和分子梳原理的共同作用。最后,对DNA液滴蒸发形成的一种“DNA多边形网状图案”进行初步研究,统计并分析了这种图案的特点和规律。
[Abstract]:The visualization and manipulation technology of monolayer DNA in solution is helpful to study the physicochemical properties of DNA molecule and its application. It also deepens the exploration of life primitive and the understanding of the basic principle of life. In addition, the ordered 2D/3D structure based on single molecule DNA can be used as a component unit of micro / nano sensor devices to carry out the research of micro detection technology in the field of life science. Molecular comb technique is a simple and efficient technique for manipulating DNA molecules in solution by interfacial tension. Combined with high resolution fluorescence imaging system and high precision contact angle analysis system, the effects of buffer and DNA molecular concentrations on the evaporation of DNA droplets and the stretching results of DNA molecules in droplet evaporation molecular comb method were studied. And DNA evaporation to form a self-assembly pattern. The main research contents are as follows: firstly, the complete stretching manipulation of DNA molecules on the surface of polymethyl methacrylate (PMMA) was realized by droplet evaporation method. High resolution fluorescence imaging microscopy was used to study the directional movement of DNA molecules in evaporated droplets, as well as the effects of buffer concentration, solution acidity and alkalinity, substrate smoothness and hydrophobicity on the tensile results of DNA. Secondly, the dynamic evaporation process of DNA droplets in different buffer solution and molecular concentration was studied by using high precision contact angle analysis system. It is found that there are two key evaporation modes in the evaporation process of DNA droplets: constant contact angle model and constant contact area model, and both of these modes are affected by buffer solution and DNA molecular concentration. The constant contact angle mode exists only at low concentration and is gradually replaced by the mixed model with the increase of concentration. The existence of constant contact angle mode is beneficial to the uniform stretching of DNA molecules. The constant contact area pattern exists generally at various concentrations, and at high concentration, the constant contact area pattern lasts longer. In this case, the stretched DNA molecules are easy to form a circular distribution pattern. Through experimental and theoretical analysis, the formation of DNA ring pattern can be attributed to the coaction of "coffee ring" effect and molecular comb principle. Finally, a "DNA polygonal mesh pattern" formed by DNA droplet evaporation was studied, and the characteristics and rules of the pattern were analyzed.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O629.74

【相似文献】