DNA purification is a vital component of many molecular assays which include PCR or qPCR as well as DNA sequencing. It removes proteins that are contaminating salts, proteins, and other impurities that hinder the downstream process. It also ensures the desired DNA is pure and is present so that it can be used for further analyses. The quality of DNA can be determined through spectrophotometry (the ratio of A260 to A280) and gel electrophoresis and other methods.

In the first step of a DNA purification process the cellular structure will be disrupted by detergents or reagents such as SDS in order to release DNA. To further purify DNA, protein-denatured reagents such as sodium dodecyl sulfate or Ethylene diamine tetraacetic acid (EDTA) are added to denature proteins, and they are removed from the nucleic acid solution with centrifugation and washing steps. If there is RNA in the sample the ribonuclease process can be added to further denature RNA. The nucleic acids are then concentrated in ice-cold alcohol to isolate them from other contaminants.

Ethanol is an everyday solvent that can be used to remove salts and other contaminants from nucleic acid samples. Researchers can compare results from different studies using the standard ethanol concentration, which is an excellent choice for workflows that require high-throughput. Other solvents, such as chloroform and phenol may be used, but these are more toxic and require additional steps to avoid cross-contamination with other cellular debris or proteins. Newer techniques can facilitate the process of DNA purification by using ethanol with low-ionic strength, which has been proven to be equally effective as conventional organic solvents in purifying DNA [2626. This is especially applicable http://www.mpsciences.com/2021/04/23/dna-purification-processes-for-different-applications/ when used in conjunction with spin column-based extract kits.