It involves breaking open the cells, removing proteins and other contaminants, and purifying the DNA so that it is free of other cellular components.
This process can be done in several ways, depending on the type of the sample and the downstream application,[3] the most common methods are: mechanical, chemical and enzymatic lysis, precipitation, purification, and concentration.
[6] DNA extraction is frequently a preliminary step in many diagnostic procedures used to identify environmental viruses and bacteria and diagnose illnesses and hereditary diseases.
The basic idea is to use a nucleic acid probe to hybridize nuclear DNA from either interphase cells or metaphase chromosomes attached to a microscopic slide.
[1] To recognize, define, and quantify the geographical and temporal patterns in marine bacterioplankton communities, researchers employ a technique called terminal restriction fragment length polymorphism (T-RFLP).
When selecting a DNA extraction method, there are multiple factors to consider, including cost, time, safety, and risk of contamination.
It also involves the unfavorable use of the toxic chemicals phenol and chloroform, and there is an increased risk of contamination due to transferring the DNA between multiple tubes.
[9] The Chelex method is much faster and simpler than organic extraction, and it only requires one tube, which decreases the risk of DNA contamination.
The chaotropic salts disrupt the hydrogen bonding between strands and facilitate the binding of the DNA to silica by causing the nucleic acids to become hydrophobic.
[12] The DNA binds to the silica, while the rest of the solution is washed out using ethanol to remove chaotropic salts and other unnecessary constituents.
The purified nuclei are then lysed and further cleaned by organic extraction, and the genomic DNA is precipitated with a high concentration of CTAB.
It's important to note that the choice of storage buffer and conditions will depend on the downstream application for which the DNA is intended.
The extracted DNA should be regularly checked for its quality and integrity, such as by running a gel electrophoresis or spectrophotometry.
The extracted DNA should be stored for as short a time as possible, and the conditions for storage should be chosen to minimize the risk of degradation.