This kit is suitable for the isolation and purification of DNA from biological fluid samples (alveolar lavage fluid, blood, sputum, swab eluate, cerebrospinal fluid, etc.). It combines chemical and mechanical lysis methods and can efficiently lyse bacterial and fungal cells with thick cell walls. The kit uses high-affinity silica-coated magnetic beads, which adsorb nucleic acids in a high-salt buffer through hydrogen bonds and electrostatic forces. Unwanted proteins and salt ions are then rinsed away, and nucleic acids will be released in a low-salt elution buffer or Nuclease-free ddH2O, enabling rapid isolation and purification of nucleic acids. The kit is compatible with an automatic nucleic acid extraction instrument (Vazyme #VNP-32P) that is based on the magnetic bead adsorption principle. Specially designed magnetic rods are used to adsorb, transfer, and release magnetic beads. By transferring the magnetic beads to the nucleic acid, the nucleic acid will be automatically extracted and purified. The DNA isolated with this kit is suitable for various downstream applications, including PCR, Real-Time PCR, metagenomic library preparation, and microarray analysis.