Method for extracting DNA by using silicic bead method in combination with centrifuge shield

The invention discloses a method for extracting DNA by using a silicic bead method in combination with a centrifuge shield. The method comprises the following steps: 1) putting detected materials into an inner sleeve of the centrifuge shield, uniformly mixing a TES buffer solution, sodium dodecyl sarcosinate and proteinase K, adding the obtained mixture into the inner sleeve, and placing the obtained object on a metal bath to crack; 2) centrifugalizing the obtained object in a centrifuge, and adding an adsorption solution for re-centrifugalizing; 3) removing the inner sleeve, adding an adsorption solution and silica bead turbid liquid, and standing for adsorption; 4) centrifugalizing the obtained object so as to remove a supernatant; 5) centrifugalizing the obtained object so as to absorb raffinate; 6) adding absolute alcohol, and centrifugalizing the obtained mixture so as to remove supernatant; 7) centrifugalizing the obtained object so as to absorb raffinate; 8) drying silica beads, and adding eluant for incubating; and 9) adding the obtained product into PCR amplification liquid to amplify. The method disclosed by the invention is high in detection rate, and the final template inventory is 50-70%, therefore, the method is especially applicable to the inspection of trace detected materials, and can detect field DNA detected materials with a template content of over 100 pg.