DNA purification is a vital process in a variety of molecular assays such as PCR or qPCR as well as DNA sequencing. It removes contaminants, such as proteins, salts and other impurities that can disrupt downstream processes. It also ensures that the desired DNA is present and pure to be further analysed. The quality of DNA can be determined by spectrophotometry, gel electrophoresis and various other methods.

The first step of the process of DNA purification is cell lysis. This is when the cellular structure is disturbed by reagents or detergents like SDS to release DNA. To further cleanse DNA, reagents which 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 DNA is present in the sample, a ribonuclease treatment could link be added to further denature the RNA. Then, the nucleic acid is reacted with ethanol that has been cooled to make it distinct from other contaminants.

Ethanol is solvent to eliminate salts or other contaminants from nucleic acids. Researchers can compare results between experiments by using the standard ethanol concentration, which is a great choice for workflows with high-throughput. Other solvents such a chloroform and phenol could be utilized, however they are more harmful and require additional steps to prevent cross-contamination with other proteins or cellular debris. Newer methods can make it easier to complete the process of DNA purification by using ethanol with a low-ionic strength that has been proven to be equally effective as traditional organic solvents in purifying DNA [2626. This is particularly applicable when used in conjunction with spin column-based extract kits.