This kit is suitable for extracting genomic DNA from ≤200 μl of fresh or frozen anticoagulated whole blood, <25 mg of animal tissue, <5 × 106 of cultured cells and <3 × 109 cultured bacterial samples. The kit is based on silica gel column purification technology that eliminates the need for extraction using phenol/chloroform organic solvents or time-consuming alcohol precipitation. With this kit, RNA, proteins, lipids and other inhibitory impurities can be removed at the greatest extent. The DNA obtained can be directly used in PCR, qPCR, restriction enzyme digestion and virus detection.