DNA purification is an essential process in many molecular tests such as PCR and qPCR. It removes proteins that are contaminating salts, proteins, as well as other impurities that can hinder the downstream process. It also ensures that the desired DNA is pure and present in order to be used for further analysis. The quality of DNA is measured through spectrophotometry (the ratio of A260 to A280) and gel electrophoresis and a variety of other methods.

The first step of the DNA purification process is cell lysis. This is when the cellular structure is broken by reagents or detergents such as SDS to release DNA. To further purify DNA, reagents that are able to denature proteins like sodium dodecyl sulfate or Ethylene Diamine Tetraacetic Acid (EDTA) can be added to denature them. The proteins are then removed from the nucleic acids solution by centrifugation and then washing. If RNA is found in the sample and is not removed, it can be denatured by adding ribonuclease. In the end, the nucleic acids is diluted with ice-cold ethanol to isolate it from other contaminants.

Ethanol can be used as solvents to remove salts or other contaminants from nucleic acid. Utilizing a standard ethanol concentration allows researchers to compare the results of different tests, making it a great choice for high-throughput workflows. Other solvents such a chloroform or phenol can be used, but these are more harmful and could require additional steps to avoid cross-contamination with other proteins or cellular debris. Newer https://www.mpsciences.com techniques can facilitate the process of purifying DNA by using low-ionic-strength ethanol that has been shown to be equally effective as the conventional organic solvents when purifying DNA [2626. This is especially true when combined with spin column extract kits.