【摘要】 报道了一种在亲水性表面拉伸裸露λDNA和DNA-微球复合物中λDNA的简单方法。将样品滴在水虎鱼溶液(piranha)和碱性过氧化氢溶液(RCA)清洗的盖玻片上,通过液滴展布与蒸发,利用静电力和表面张力相互作用,将DNA分子伸展并平铺在玻片表面上。激光共聚焦荧光显微镜成像表明,该方法可以较好地将这两种状态的DNA拉直,拉伸长度大于氨基硅烷修饰的表面拉伸方法,同时,也避免了以往一些分子梳过度拉伸而造成DNA变性的弊端。该方法为在单分子水平研究DNA的物理特性和DNA-蛋白质的相互作用提供了新的途径,也为大规模操纵单分子DNA提供了可能。更多还原

【Abstract】 This paper reports a simple method of stretching single naked and microbead-conjugatedλDNA molecules on hydrophilic surfaces.Sample was dropped on the coverslip washed by Piranha and RCA,then the drop started to spread and evaporate.So,DNA molecules were stretched and alined on the coverslip by the interaction of electrostatic force with surface tension at the interface of air and solution.Confocal images demonstrated that this method could properly stretch single DNA molecules in both states,resulting longer stretched DNA molecules than those stretched on aminosilane-modified surface.In the meantime,this method has circumvented overstretching of DNA molecules caused by other methods,which can lead to DNA denaturation and loss some of its important biological activities,providing a new alternative for studies of DNA physical properties and interactions between DNA and proteins at the single molecule level.In addition,it also provides possibilities for manipulation of single DNA molecules at large scales.更多还原