This kit is intended for isolation and purification of DNA and RNA from biological fluid samples (alveolar lavage fluid, blood, sputum, cerebrospinal fluid, swab eluate, etc.) and microbial cultures. It combines chemical and mechanical lysis methods and can efficiently lyse bacterial and fungal cells with thick cell walls. The kit uses high-affinity silicon-based 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. Nucleic acids will be released in a low-salt eluent or Nuclease-free ddH2O, enabling fast isolation and purification of nucleic acids. The extraction process with this kit is safe, fast, and simple as toxic reagents such as phenol and chloroform are not required. While ensuring efficiency in nucleic acid extraction, the kit also minimizes proteins, inorganic salts, and other impurities. The isolated DNA and RNA are suitable for various downstream applications, including PCR, real-time PCR, metagenomic library preparation,and DNA/RNA library preparation.