A high-quality sample of DNA is essential for a range of downstream applications, including PCR and sequence. DNA purification is the process of eliminating contaminants like proteins and other cellular components, from a sample in order to create a pure nucleic acids solution ready for use. There are a variety of DNA purification techniques, each with their own advantages and drawbacks depending on the material used as a starting point or application.

The first step of DNA purification is to remove protein from the sample with a protease (proteinase enzyme) or mechanical disintegration. After the cellular debris has been removed, the DNA may be extracted using ethanol to form a stringy, white precipitate. The precipitated DNA is then returned to the water or sterile buffer. The DNA’s concentration can then be determined by spectrophotometry, based on the peak of absorbance for nucleic acids that are 260 nm.

Salting out is a different method of DNA purification. A column of cellulose is utilized in this process to collect and connect DNA. The cellulose matrix must be treated with detergents to remove any contaminants. A wash buffer is then applied to eliminate the salts. DNA binds to the matrix under low salt conditions and contaminating proteins as well as DNA can be eliminated by using higher salt solutions. The eluted DNA and RNA are then http://www.mpsciences.com/2021/04/23/dna-purification-processes-for-different-applications/ recovered through the ethanol precipitation.

Anion exchange chromatography is a method used for DNA purification. This method employs a cation exchange resin to attract positively charged DNA molecules, and neutralizing resins allow negatively charged DNA to be flushed out of the column. Once the DNA is eluted the eluted DNA can be concentrated using centrifugation. Then, the DNA can be separated by washing it with 70 percent ethanol at temperatures that are ice cold.