DNA purification is among the most popular and significant procedures in molecular biology. Purification of DNA is aimed at separating the desired genetic material (chromosomal material) from other contaminants like proteins or RNA as well as the cell membrane. This is a crucial procedure in almost every molecular procedure and must be executed correctly to get the highest quality usable DNA.
There are a variety of different methods that can be used for DNA purification, the choice of which depends on several factors, such as the source materials and downstream applications along with cost and time constraints. The most common DNA purification techniques include chemical treatment, enzymatic digestion, or mechanical disruption of tissue/cell samples followed by salting-out of proteins and the precipitation of DNA using ethanol.
Ethanol precipitation is a straightforward, cost-effective and fast method for desalting and concentration of DNA. DNA molecules accumulate in the presence monovalent cations like sodium, and then they are removed out of solution using high levels of ethanol. This method is employed to remove salts, organic compounds and other impurities. It is frequently employed in conjunction with other purification methods.
Another method used for DNA purification is anion exchange chromatography. DNA in a solution gets bound to positively charged resins by the interaction between the negatively charged DNA phosphate backbone and the positively charged surface molecules of the resin. During the binding steps, contaminants are removed by the use of a rigorous washing process. The DNA that is purified is eluted under low salt conditions.