DNA purification is a typical and important procedure in molecular biology. The goal of DNA purification is the separation of the desired genetic material from contaminants (proteins, cell membranes and RNA). This is an essential procedure in nearly every molecular application and must be carried out correctly to get high-quality, usable DNA.

There are a variety of different methods that can be used for DNA purification, the choice of which depends on several aspects, including the materials used to start and downstream applications as well as the cost and time limitations. Common DNA purification techniques include chemical treatment, enzymatic digestion or mechanical disintegration of samples of cells or tissues followed by salting-out of proteins and precipitation of the DNA with ethanol.

Ethanol precipitation is an inexpensive easy and quick method of desalting and concentrating DNA. DNA molecules form aggregates when they are in the presence of monovalent cations like sodium, and are then filtered out of solution by large amounts of alcohol. This method allows the removal of salts, organic compounds and other impurities from a sample and is often used in conjunction with other purification techniques.

Another method that is popular for DNA purification is anion why not look here exchange chromatography. DNA in solution is linked to positively charged resins via the interaction between the negatively charged DNA phosphate backbone as well as the positively charged surface molecules of the resin. During the binding and washing processes in the process, contaminating molecules are eliminated from the DNA using strict wash steps and the DNA purified is eluted using low salt conditions.