DNA purification is one of the most common and important procedures in molecular biology. The purpose of DNA purification is the separation of the desired genetic material from the contaminant (proteins, cells membranes and RNA). This is a crucial step in almost every molecular application and must be done correctly in order to obtain high-quality, usable DNA.
There are several different methods for DNA purification. The selection of the method is contingent on a range of factors, such as the starting materials, downstream applications, cost, and time constraints. The most common genomic and plasmid DNA purification protocols include chemical treatment, enzymatic digestion or mechanical disruption of tissue/cell samples followed by salting out of the proteins and the precipitation of DNA using ethanol.
Ethanol precipitation is an inexpensive easy and quick method of desalting and concentration DNA. DNA molecules form aggregates when they are in the presence of monovalent cations like sodium and are then precipitated out of solution using high levels of ethanol. This method is employed to remove salts, organic compounds http://www.mpsciences.com/2021/04/01/types-of-science-products-available/ and other impurities. It is usually employed in conjunction with other purification methods.
Another method that is popular for DNA purification is anion exchange chromatography. The interaction between negatively charged DNA phosphate phosphate backbones, as well as the positively charged surface molecules of resins binds DNA in a solvent with positively charged resins. During the binding and washing steps removal of contaminating molecules from DNA through rigorous wash steps, and then the DNA purified is eluted using low salt conditions.