The Basics of DNA Purification

DNA purification is an essential step in many molecular tests, such as PCR and qPCR. It removes proteins that are contaminating salts, proteins, as well as other impurities that interfere with the downstream process. It also ensures that the desired DNA is pure and present in a way that it can be used for further analyses. The quality of DNA can be assessed through spectrophotometry and electrophoresis on gels and other methods.

The first step of the process of DNA purification is cell lysis, in which the cellular structure is disturbed 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 https://mpsciences.com/ be added to denature them. The proteins are removed from the nucleic acids solution by centrifugation and washing. If there is RNA in the sample, a ribonuclease treatment can be added to further denature RNA. In the end, the nucleic acids is reacted with ethanol that has been cooled to make it distinct from other contaminants.

Ethanol is a solvent to remove salts or other contaminants from nucleic acids. Researchers can evaluate the results of different experiments by using the standard ethanol concentration, which is a good option for workflows with high-throughput. Other solvents, including chloroform and phenol, can be used, however, they are more harmful and require additional steps to avoid cross-contamination. Newer techniques can facilitate the DNA purification process using low-ionic-strength ethanol, which has been proven to be equally effective as traditional organic solvents for purifying DNA [26]. This is especially relevant when used in conjunction with spin column extract kits.