Study On DNA Molecular Manipulation Technology In Liquid Phase Based On Substrate Modification

The core role of DNA molecules in various life processes makes the research on DNA level of great scientific value and practical significance.Due to the unique structure and functional characteristics of DNA,how to precisely manipulate and control a single DNA molecule has become a hot topic in current DNA molecule research.Traditional biological research methods are based on a large number of samples,and it is difficult to realize accurate imaging and manipulation at nanometer level.However,nanotechnology based on atomic force microscope is widely used in the research process of biomolecules due to its advantages of high space resolution at nanometer level and force resolution at pico-newton level.In this paper,the direct observation,characterization and manipulation of DNA molecules by atomic force microscopy have been deeply studied.In view of the difficulty of clear imaging of DNA molecule caused by the linear double helix structure of DNA molecule itself and the irregular distribution of curl in solution,this paper deeply studies the weak current characteristics of DNA molecule and establishes a model of electric field manipulating DNA molecule.The stress of DNA molecules in electric field was analyzed by ANSYS software,which provided theoretical research basis for subsequent experiments.In order to solve the adverse effect of sample aggregation on imaging,we combine ion modified substrate and direct current electric field,which effectively promote the stability of DNA molecular samples in testing experiments and change the irregular distribution of DNA molecular curling.The influence of ion concentration on DNA molecular imaging clarity was analyzed quantitatively and qualitatively.In addition,the relationship between ion concentration and adhesion was studied,and DNA molecules in liquid phase were imaged and adhesion characteristics were detected.By studying DNA molecules manipulated by mechanical force,the cutting operation of DNA molecules by atomic force microscope is realized.The experimental results show that the electric field control based on ion modification can better enhance the success rate of DNA molecular manipulation,which provides an effective means and approach for further DNA molecular research.