Different Methods for DNA Purification
DNA purification is a typical and important procedure in molecular biology. Purification of DNA is aimed at making it possible to separate the desired genetic material (chromosomal material) from harmful substances like proteins as well as RNA and cell membrane. This is an essential procedure in almost every molecular procedure and must be carried out correctly to ensure the highest quality, usable DNA.
There are many different methods for DNA purification, the choice of which is dependent on a number of factors, including the starting materials and downstream applications along with cost and time limitations. The most common DNA purification protocols include chemical treatment, enzymatic digestion or mechanical disruption of tissue or cell samples followed by salting out of the proteins and the precipitation of DNA with ethanol.
Ethanol precipitation is a simple cheap and fast method of desalting and concentrated DNA. DNA molecules are aggregated in the presence monovalent cations like sodium, and then they are removed from the solution using high concentrations ethanol. This method is employed to remove salts, organic compounds, and other impurities. It is commonly employed in conjunction with other purification methods.
Another method used for DNA purification is anion exchange chromatography. The interaction between the negatively-charged DNA phosphate backbones as well as the positively charged surface molecules of resins binds DNA in a solvent with positively charged resins. During the binding process removal of contaminants is accomplished using a stringent washing process. The purified DNA then is eluted under low-salt conditions.