The structure and function of nucleic acids are the basis of molecular life activities. DNA and RNA are the most important nucleic acid molecules in organisms, and they are the research objects of molecular biology and molecular diagnosis. Therefore, the isolation, purification and storage of nucleic acids are essential and extremely important steps in molecular biology research and molecular diagnosis of diseases. The integrity of the nucleic acid structure should be maintained as much as possible during the purification of the nucleic acid and the purity of the nucleic acid should be as high as possible.