The Shanghai Lifefeng Biotechnology Co., Ltd. Endotoxin-free Plasmid DNA Small Extraction Kit uses the SDS/alkaline lysis method to release plasmid DNA, selectively adsorb plasmid DNA to remove the vast majority of endotoxins, high-salt ion elution, further phase separation to remove residual endotoxins, isopropanol precipitation to recover plasmid DNA, and the volume of DNA dissolution can be determined according to experimental needs. Taking parallel processing of 4 samples as an example, the operation time is about 100min.