bo finneman

Before doing an PCR reaction or cloning test or DNA sequencing it is critical to have a high-quality DNA that is free of contaminants like debris, proteins and RNA. Purifying DNA is also referred as DNA Isolation, and is a crucial step in molecular biology. This article will explain the fundamentals of DNA extraction and how to optimize it for better results.

The initial step in the DNA purification process is to prepare a solution that contains a mixture consisting of water and alkaline buffer. This buffer makes DNA soluble, so it is easily separated from the other components of the sample. After the DNA is placed in an alkaline solution and a water solution, it is then treated with detergents and salts that break down cells’ membranes and nuclei. This lets the DNA out. RNase can be added to the sample to remove any DNA that is contaminating.

The DNA is separated by organic solvents, such as chloroform or phenol from other cellular components like proteins and fats. After the DNA has been removed from the proteins and lipids, they can be extracted using ethanol, or isopropyl alcohol (rubbing alcohol).

The quality of the DNA can be confirmed using spectrophotometry, or gel electrophoresis. A good quality DNA sample should have an absorbance ranging from 260 nm to 280 nm of 1.8. A low ratio could be a sign of a problem in the protein binding steps or a salt carryover from wash or bind buffers.