The Basics of DNA Purification
Release time：2024-04-10
Before performing the PCR reaction, cloning experiment or DNA sequencing it is critical to have high-quality DNA that is free of contaminants, such as particles, proteins and RNA. The process of purifying DNA is referred to as DNA isolation, and is one of the most important steps in molecular biology. In this article, you will discover the fundamentals of DNA purification and how you can optimize your DNA extraction methods to get better results.
The first step of the DNA purification process is to make a solution consisting of the mixture of alkaline buffer and water. This buffer makes DNA soluble, which means it is easy to separate from the other components of the sample. After the DNA is placed in an alkaline and water solution, it’s then treated with detergents or chaotropic salts to break down cell membranes and nuclei and release DNA (cell lysis). RNase is also added to remove any contamination of RNA from the sample.
DNA is then separated from other cell components like proteins and lipids using organic solvents such as chloroform and phenol. After the DNA has been removed from proteins and lipids, it can be extracted using ethanol, or isopropyl alcohol (rubbing alcohol).
The purity of the DNA sample can be determined by spectrophotometry or gel electrophoresis. A high-quality sample of DNA should have an absorbance ratio of between 220 nm to 280 nm.