Plasmid Captarose HF/Plasmid Captarose HR is a thiophilic affinity chromatography resin prepared by coupling 2-mercaptopyridine ligands to a highly rigid agarose matrix. The separation principle of thiophilic affinity chromatography utilizes interactions between electron donors and acceptors to purify biomolecules, with these interactions being enhanced under high-salt conditions and diminished under low-salt conditions. Plasmid Captarose HF/Plasmid Captarose HR is primarily used for the purification of supercoiled plasmid DNA. During the purification process, supercoiled plasmid DNA binds to the resin while open circular plasmid DNA does not interact with the resin, achieving separation. The high-quality supercoiled plasmid DNA obtained after purification is commonly used in gene therapy or as DNA vaccines.