Before doing any PCR reaction or cloning experiment, or even DNA sequencing, it is essential to have a high-quality DNA source that is free of contaminants such as protein, debris and RNA. Purifying DNA is also referred as DNA isolation and is a vital step in molecular biology. In this article, you will learn the fundamentals of DNA purification, and how to improve your DNA extraction processes to get more efficient results.
The first step in the process of purifying DNA is to prepare a solution that is composed of water and an alkaline buffer. This buffer makes DNA soluble and it is easily separated from other components of the sample. After the DNA has been placed in an alkaline and water solution, it is treated with detergents and chaotropics salts to break up cells’ membranes and nuclei. This releases the DNA. RNase can be added to the sample to remove any contaminating DNA.
The DNA is separated by organic solvents, such as chloroform and phenol from other components of the cell like fats and proteins. After the DNA is removed from the proteins or lipids and lipids, it can be precipitated using alcohol or ruby alcohol.
Spectrophotometry and Gel Electrophoresis can be used to determine the quality of DNA. A high-quality sample of DNA should have an absorbance range of the 260-nm range and 280-nm range.