Silica based technology
This is a widely employed method in current kits. DNA adsorbs specifically to silica membrane/beads/particles in the presence of certain salts and at a particular pH. The cellular contaminants are removed by wash steps. DNA is eluted in a low salt buffer or elution buffer. Chaotropic salts are included to aid in protein denaturation and extraction of DNA. This method can be incorporated in spin columns and microchips, is cost effective, has a simpler and faster procedure than the organic extraction, and is suitable for automation. Kits based on this method include Purelink Genomic DNA extraction kit (Invitrogen), DNeasy Blood and Tissue Kit (Qiagen).