DNA purification is a common and essential procedure in molecular biology. The purpose of DNA purification is to isolate the desired genetic material from the contaminant (proteins, RNA and cell membrane). This is a vital process in nearly all molecular processes and must be done correctly in order to obtain top-quality, usable DNA.
There are a variety of options for DNA purification. The selection is based on a myriad of factors such as the starting materials and downstream applications, costs, and time constraints. The most common genomic and plasmid purification techniques require chemical treatment, enzymatic digesting or mechanical disruption of cells or tissues followed by salting of the proteins and removing the DNA using alcohol.
Ethanol precipitation is a straightforward, cost-effective and fast method of desalting and concentrated DNA. DNA molecules form aggregates in the presence of monovalent cations like sodium, and are then filtered out of solution with high concentrations of alcohol. This technique permits the removal of salts, organic compounds, and other impurities in a sample. It is frequently used in combination with other purification methods.
Anion exchange is another well-known method for DNA purification. The interaction between negatively charged DNA phosphate phosphate backbones, as well as the positively charged surface molecules of resins bind DNA in a solvent and positively charged resins. During the binding and washing processes removal of contaminating molecules from the DNA via rigorous wash steps and the purified DNA is eluted in low salt conditions.
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