Abstract: Plasmid DNA is most common carrier for genetic engineering and gene vaccine，it is widely applied in biomedical and environmental science in recent years. Purification of plasmid DNA is the common techndogy in molecular biology，while solid phase carriers such as magnetic nanoparticles and chromatographic techniques have promoted the methods of purification of DNA. We present the methods of purification of plasmid DNA，endotoxin removal strategies and automatic nucleic acid purification device which are suited for plasmid DNA isolation，to privide the supports for application of plasmid DNA.

Key words: plasmid DNA, endotoxin, automatic nucleic acid purification device