It is crucial to have high quality DNA that is free of contamination such as debris, protein, 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. In this article you will be taught the fundamentals of DNA purification, and how to optimize your DNA extraction strategies for better results.
The first step of the DNA purification procedure is to prepare a solution that contains a mixture consisting of water and alkaline buffer. This buffer makes DNA soluble, which means it is easily separated from other components of the sample. Once the DNA has been placed in a water and alkaline solution, it is then treated with chaotropic or detergents to remove cell membranes and nuclei and release DNA (cell lysis). RNase can be added to the sample to remove any DNA that is contaminating.
The DNA is separated by organic solvents such chloroform and phenol from other cellular components including proteins and fats. After the DNA is removed from lipids or proteins, it can be precipitated by alcohol or ruby alcohol.
Spectrophotometry and electrophoresis may be bo finneman used to determine the quality of DNA. A high-quality sample of DNA should have an absorbance range of 220 nm to 280 nm.