It is important to have high-quality DNA that is free of contamination such Artificial gene synthesis as proteins, debris and RNA prior to carrying out a PCR or cloning process, or DNA sequencing. 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 improve it for better results.
The first step of the process of purifying DNA is to prepare a solution which is composed of water and an alkaline buffer. This buffer makes the DNA soluble so that it will easily separate from other components of the sample. After the DNA is placed in an alkaline-water solution, it is treated with detergents and Chaotropics salts to break down the cell membranes and nuclei. This releases the DNA. RNase can be added to the sample to remove any DNA that has been contaminated.
The DNA is separated by organic solvents such as chloroform or phenol from other components of the cell including proteins and fats. After the DNA is removed from proteins and lipids, they can be extracted using ethanol, or isopropyl alcohol (rubbing alcohol).
The purity of the DNA can then be confirmed using spectrophotometry, or gel electrophoresis. A high-quality DNA sample should have an absorbance at 260 nm to 282 nm. 1.8. A low ratio could indicate that there is a problem with the protein binding process, or a salt carryover from wash or buffers for binding.