DNA purification is a critical procedure in many molecular tests, including PCR and qPCR. It eliminates harmful proteins as well as salts and other impurities which hinder the downstream process. It also ensures that the desired bo finneman DNA is clean and in good condition in order to be further analysed. The quality of DNA is assessed through spectrophotometry (the ratio of A260 to A280) and gel electrophoresis and other methods.
The first step in the DNA purification process is cell lysis, in which the cellular structure is broken by reagents or detergents such as SDS to release DNA. To further cleanse DNA, reagents which denature proteins such as sodium dodecylsulfate or Ethylene Diamine Tetraacetic Acid (EDTA) can be added to denature them. The proteins are then removed from the nucleic acid solution by centrifugation and washing. If RNA is found in the sample and is not removed, it can be denatured by adding ribonuclease. The nucleic acids are then concentrated in ice-cold water to separate them from other contaminants.
Ethanol is a popular solvent that can be used to remove salts and other contaminants from nucleic acid samples. Researchers can evaluate the results of different experiments using an ethanol concentration that is standard, which is a good choice for high-throughput workflows. Other solvents such as chloroform and phenol may be utilized, but they are more harmful and could require additional steps to avoid cross-contamination with other proteins or cellular debris. The purification of DNA can be simplified by using low ionic strength ethanol. This has been demonstrated to work just as conventional organic solvents in purifying DNA. This is especially relevant when used in conjunction with spin column extract kits.
