Method for accurately extracting and separating intracellular and extracellular DNA (deoxyribonucleic acid) in natural water body

The invention discloses a method for accurately extracting intracellular and extracellular DNA in a natural water body, and belongs to a DNA extraction technology in the biological field. The method comprises the following steps: adding an extracting agent capable of being combined with metal ions into a target water body containing transparent extracellular polymeric particles, enabling the transparent extracellular polymeric particles to be completely broken under the action of the extracting agent after the transparent extracellular polymeric particles are uniformly dispersed, releasing intracellular and extracellular DNA on the transparent extracellular polymeric particles into the target water body, and then carrying out centrifugal treatment to obtain a supernatant containing all the intracellular and extracellular DNA. Filtering the supernate through a filter membrane, collecting extracellular DNA into filtrate, and collecting intracellular DNA onto the filter membrane, so as to finish precise separati