This product is suitable for extracting 20~100μg of endotoxin-free plasmid DNA from 10~15 ml of bacterial culture medium, and the product adopts a unique solution system to process a variety of plasmid vectors, including conventional vectors with high and low copy numbers, large vectors, such as BAC, Cosmid, P1, etc. DNA yield depends on vector copy number and bacterial volume. The endotoxin content of the purified plasmid is less than 1EU/μg, which can be directly used for cell transfection, animal injection, etc.