DNA purification is a vital process in many molecular tests such as PCR and qPCR. It removes contaminating proteins, salts, and other impurities which hinder the downstream process. It also ensures that the desired DNA is in good condition and pure to be used for further analysis. The quality of DNA can be determined by spectrophotometry (the ratio of A260 to A280), gel electrophoresis, and other methods.
In the beginning of a DNA purification procedure, the cellular structure will be disrupted by using detergents or reagents such SDS to release DNA. To further purify DNA, protein-denatured reagents like sodium dodecyl sulfate and Ethylene diamine tetraacetic acids (EDTA) are used https://mpsciences.com/2021/04/01/types-of-science-products-available/ to denature proteins. Then, they are removed from the nucleic acid solution using centrifugation and wash steps. If RNA is detected within the sample then it can be further denatured by adding ribonuclease. The nucleic acid is then concentrated in ice-cold alcoholic to separate them from other contaminants.
Ethanol can serve as a solvent to remove salts and other contaminants from nucleic acids. Using a standardized concentration of ethanol permits researchers to analyze the results of multiple experiments, which makes it an ideal choice for workflows that require high-throughput. Other solvents, such as chloroform and phenol could be used, however, they are more toxic and may require additional steps to avoid cross-contamination with other proteins or cellular debris. The process of purifying DNA can be simplified by using ethanol with low ionic strength. This has been demonstrated to work just as conventional organic solvents at eliminating DNA. This is especially the case when paired with spin column-based extract kits.
