NOVELTY - DNA extraction involves cleaning of sludge, where 2 g of anaerobic activated sludge is inserted in a 1.5 ml of centrifuge tube in which 1 ml of phosphate buffered saline (PBS) buffer solution is added. The centrifuge tube is shaken and centrifuged for one minute at 9000 revolutions per minute. The sludge is accumulated at the lower part of the centrifuge tube centrifuged twice to obtain cleaned anaerobic activated sludge. 100 mg of cleaned anaerobic activated sludge is taken into 1.5 ml centrifuge tube.    USE - Method for extracting DNA from anaerobic activated sludge (Claimed).    ADVANTAGE - The DNA extraction method provides highly pure DNA with high yield.    DETAILED DESCRIPTION - DNA extraction involves cleaning of sludge in which phosphate buffered saline (PBS) buffer solution is added, where sludge is accumulated at the lower part of the centrifuge tube, in which lysed cells, 0.5 g of quartz sand, 40 microliter of DNA extraction buffer solution, 20 microliter of RNA enzyme with a concentration of 40 mg per ml and 160 microliter of lysozyme with a concentration of 100 mg per ml are added. The centrifuge tube is reversed 20-30 times and 400 microliter of DNA extraction buffer solution, 40 microliter of protease K and 600 microliter of sodium dodecyl sulfate buffer solution are added in the centrifuge tube and the centrifuge tube is rotated at 9000 revolutions per minute. The supernatant is transferred to other centrifuge tube. The DNA is purified by adding isopropanol, where one fourth of isopropanol is added to the supernatant and centrifuged at 9000 revolutions per minute for 15 seconds. The obtained liquid is poured in a collecting tube, which is centrifuged at 9000 revolutions per minute for 15 seconds and 500 microliter of ethanol is added to the centrifuge tube and again centrifuged at 9000 revolutions per minute for 30 seconds. The material of the centrifuge tube is transferred to a new collecting tube. 100 microliter of tris solution is added to the centrifuge tube which is centrifuged at 12000 revolutions per minute to obtain DNA from anaerobic activated sludge.