DNA purification is a typical and crucial procedure in molecular biology. The purpose of DNA purification is to separate the desired genetic material, chromosomal material from the contaminant (proteins, cell membranes, and RNA). This is an essential step in almost all molecular processes and must be performed correctly in order to obtain top-quality, usable DNA.
There are several different methods for DNA purification. The selection is based on a myriad of factors, such as the starting materials and downstream applications, costs, and time constraints. Common DNA purification methods include chemical treatment, enzymatic digestion or mechanical disruption of tissue or cell samples followed by salting-out the proteins and precipitation of the DNA using ethanol.
Ethanol precipitation is an inexpensive, quick and simple method of desalting and concentrating DNA. DNA molecules form aggregates when they are in the presence of monovalent cations, such as sodium, and are then filtered out of solution by high concentrations of ethanol. This method is employed to remove organic compounds, and other impurities. It is frequently used with other purification methods.
Anion exchange chromatography is a different popular method for DNA purification. The interaction between the negatively-charged DNA phosphate backbones as well as the positively-charged surface molecules of resins is what binds DNA in a solvent with positively charged resins. During the binding process, contaminants are removed by making use of a strict washing process. The DNA that has been purified is eluted under low-salt conditions.