The Geno/midi AX DNA Isolation Spin-Kit includes unique ion-exchange membranes of unusual high DNA binding capacity. Samples like bacterial or tissue lysates are loaded onto the columns with the ion-exchange membranes. The DNA is bound to the membrane at an efficiency of 99 %, while most of the impurities easily pass through. Washing step（s） remove residual impurities. Subsequently, the DNA is eluted from the column with a high ionic strength solution. To obtain the highest purity, the eluted DNA is desalted and concentrated by precipitation. Finally, the DNA can be dissolved in the desired volume of water or appropriate buffer.