DNA purification is among the most common and important methods used in molecular biology. The goal of DNA purification is the separation of the desired genetic material, chromosomal materials from contaminants (proteins, cell membranes, and RNA). This is a critical step in almost every molecular process and must be performed well in order to produce high quality usable DNA.
There are a variety of methods for DNA purification. The selection of the method is contingent on a myriad of factors including the starting materials and downstream applications, costs and time limitations. Typical DNA purification methods include chemical treatment, enzymatic digestion or mechanical disintegration of samples of cells or tissues followed by salting-out of the proteins and precipitation of the DNA using alcohol.
Ethanol precipitation is a simple, inexpensive and quick method for desalting and concentrating DNA. DNA molecules form aggregates in the presence of monovalent cations like sodium and then precipitated out of solution using high levels https://mpsciences.com/2021/04/23/dna-purification-processes-for-different-applications/ of ethanol. This technique permits the removal of salts, organic compounds, and other impurities from the sample and is often used in combination with other purification methods.
Another method of DNA purification is anion exchange chromatography. DNA in a solution is bonded 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 and washing processes, contaminating molecules are removed from the DNA by stringent washing steps, and the purified DNA is eluted in low salt conditions.