DNA purification is one of the most frequently used and vital processes in molecular science. Purification of DNA aims at getting rid of the desired genetic material (chromosomal material) from contaminants such as proteins, RNA, and cell membrane. This is a vital step in almost all molecular applications. It must be done correctly in order to obtain high-quality and usable DNA.
There are a variety of different methods that can be used for DNA purification, the selection of which is based on a variety of factors, including starting materials and downstream applications along with cost and time limitations. Typical genomic and plasmid DNA purification DNA purification steps protocols include chemical treatment, enzymatic digestion, or mechanical destruction of cell samples or tissue followed by salting-out of the proteins and precipitation of the DNA with ethanol.
Ethanol precipitation can be a low-cost, quick and simple method of desalting and concentrating DNA. DNA molecules accumulate in the presence of monovalent Cations like sodium and then they are removed from solution using high concentrations ethanol. This technique allows the removal of salts, organic compounds and other impurities in a sample. It is frequently used in conjunction with other purification techniques.
Another method that is popular for DNA purification is anion exchange chromatography. The interaction between negatively charged DNA phosphate backbones and positively-charged surface molecules of resins is what binds DNA in a solvent and positively charged resins. During the binding steps, contaminants are removed by using a stringent washing process. The DNA that is purified is eluted under low salt conditions.