It is essential to have high quality DNA that is free of contamination such as proteins, debris, and RNA before performing the PCR, cloning, or DNA sequencing. The process of purifying DNA is known as DNA isolation and is considered to be one of the most important steps in molecular biology. This article will help you understand the basics of DNA extraction and how to optimize it for better results.

The initial step of the DNA purification procedure is to prepare a solution containing an amalgamation of alkaline buffer and water. This buffer makes the DNA more soluble so that it can easily be separated from the other components of the sample. Once the DNA has been placed in an alkaline and water solution, it is then treated with chaotropic or detergents to remove cell membranes and nuclei and release the DNA (cell lysis). RNase can be added to the sample to eliminate any DNA that is contaminating.

The DNA is then separated by organic solvents such as chloroform or phenol from other cellular components, such as fats and proteins. After the DNA is removed from proteins and lipids, it is able to be precipitated using ethanol or isopropyl alcohol (rubbing alcohol).

Gel electrophoresis and spectrophotometers can be used to determine the purity of DNA. A good quality DNA sample should have a ratio of absorbance of 260 nm up to the range of 280 nm. 1.8. A low ratio could signal an issue with the protein binding processes or the carryover of salt from wash or bind buffers.

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