This kit is suitable for extracting 150-300 ml of overnight cultured bacteria, using an improved SDS-alkaline lysis method to lyse the bacteria, the crude extract is selectively combined with a unique endotoxin scavenger and centrifuged to remove endotoxins, and then The silicon matrix membrane in the centrifugal adsorption column selectively binds the plasmid DNA in the solution under high salt and low pH conditions, and then removes impurities and other bacterial components through the rinsing solution, and finally elution with low salt and high pH The buffer eluted purified plasmid DNA from the silicon matrix membrane. The silicon matrix membrane in the centrifugal adsorption column all adopts imported special adsorption membrane, the adsorption amount difference between the column and the column is very small, and the repeatability is good. There is no need to use toxic phenol, chloroform and other reagents, nor ethanol precipitation. It can quickly extract 0.2-1.5 mg of pure high-copy plasmid DNA with an extraction rate of 80-90%. The unique process formula removes endotoxin, the content of endotoxin is very low (< 0.1 EU/μg DNA), and the cell transfection effect is excellent. It can also be directly used in various molecular biology experiments such as enzyme digestion, PCR, in vitro transcription, transformation, sequencing, and so on.   High Yield; Compatible with the extraction of plasmids of different lengths; The content of endotoxin is extremely low, and subsequent transfection level experiments can be done; Good stability   RNase A should be stored at -30 ~ -15℃; The endotoxin scavenger can be stored at 2-8℃ for one month, please store at -30 ~ -15℃ for long-term storage; The other components of the kit are stored at room temperature (15 ~ 25℃).