DNA purification is an https://mpsciences.com/2021/02/15/science-supplies-for-students/ essential step in many molecular assays which include PCR or qPCR, as well as DNA sequencing. It removes contaminants, such as proteins, salts, and other impurities which can hinder downstream processes. It also ensures that the desired DNA is clean and in good condition to be further analysed. The quality of DNA can be determined using spectrophotometry (the ratio of A260 to A280) or gel electrophoresis and other methods.

In the initial stage of a DNA purification process the cellular structure is going to be disrupted with detergents or reagents such SDS in order to release DNA. To further purify DNA, reagents designed to denature proteins such as sodium dodecylsulfate 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 RNA is found in the sample then it can be further denatured by adding ribonuclease. The nucleic acid is concentrated with ice-cold ethanol to make it distinct from other contaminants.

Ethanol is a popular solvent that can be used to remove salts and other contaminants from nucleic acid samples. The use of a standardized concentration of ethanol allows researchers to compare results across experiments, which makes it an ideal choice for high-throughput workflows. Other solvents such as chloroform and phenol may be used, however, they are more harmful and require additional steps to prevent cross-contamination with other proteins or cellular debris. The process of purifying DNA can be simplified by using low ionic strength ethanol. This has been shown to be effective as traditional organic solvents at cleaning DNA. This is especially true when combined with a spin column-based extract kit.