DNA purification is a vital step in many molecular assays such as PCR as well as qPCR and DNA sequencing. It removes contaminating proteins as well as salts and other impurities that hinder the downstream process. It also ensures the desired DNA is completely clean and present so that it can be used in further studies. The quality of DNA is assessed using spectrophotometry (the ratio of A260 to A280) or gel electrophoresis and other methods.
In the beginning of a DNA purification procedure the cell structure will be disrupted with detergents or reagents like SDS to release DNA. To further purify DNA, reagents designed to denature proteins such as sodium dodecyl sulfate or Ethylene Diamine Tetraacetic Acid (EDTA) can be added to denature them. The proteins are removed from the nucleic acids solution by centrifugation and washing. If there is RNA present in the sample the ribonuclease process can be added to further denature the RNA. Finally, the nucleic acid is reacted with ethanol that has been cooled to isolate it from other contaminants.
Ethanol is solvents to remove salts and other contaminants from nucleic acid. The use of a standardized concentration of ethanol lets researchers examine the results of various experiments, which makes it a good option for workflows that require high-throughput. Other solvents like chloroform or phenol can be used but they are more hazardous and require additional steps to prevent cross-contamination. The purification of DNA can be made simpler by using ethanol that has a low ionic strength. It has been proven to be as effective as traditional organic solvents at purifying DNA. This is especially applicable when used in conjunction with spin column-based extract kits.
https://mpsciences.com/2021/04/15/gene-synthesis-and-transcription-processes/