What are the methods or types of DNA extraction?
The correct answer and explanation is:
Methods of DNA Extraction
DNA extraction is a crucial laboratory technique used to isolate DNA from cells for various applications in genetics, molecular biology, and forensic science. There are several methods for extracting DNA, each with advantages and specific applications. The most common types of DNA extraction methods include:
- Organic Extraction (Phenol-Chloroform Method)
This method uses phenol and chloroform to separate DNA from proteins and lipids. The organic solvents denature proteins while leaving DNA intact in the aqueous phase. The DNA is then precipitated using ethanol or isopropanol. This method is highly effective but involves toxic chemicals. - Silica-Based Extraction (Spin Column Method)
This is a widely used method in commercial DNA extraction kits. It utilizes silica membranes to bind DNA in the presence of chaotropic salts. After several washing steps, pure DNA is eluted with a buffer or water. This method is fast, highly efficient, and widely used in clinical and research applications. - Magnetic Bead-Based Extraction
Magnetic beads coated with DNA-binding molecules selectively capture DNA from a sample. A magnetic field is used to separate the beads from unwanted material, followed by DNA elution. This method is automation-friendly and ideal for high-throughput applications. - Salting-Out Method
This method uses high concentrations of salt (e.g., potassium acetate) to precipitate proteins while leaving DNA in solution. The DNA is then precipitated with alcohol. It is a cost-effective and non-toxic alternative to organic extraction. - Chelex Extraction
Chelex resin binds metal ions that degrade DNA, protecting it from degradation. It is simple, rapid, and commonly used in forensic applications but yields single-stranded DNA, limiting some downstream applications.
Each method has its specific advantages depending on the sample type, purity requirement, and downstream applications.