DNA & RNA Purification
Extraction of DNA and RNA is a fundamental technique in molecular biology, serving as the basis for a variety of research and clinical applications. High-quality, highly pure nucleic acids are essential for accurate and reliable results in numerous genomic and molecular biology workflows. Nucleic acid purification is typically one of the first steps in these processes, ensuring that the extracted genetic material is free from contaminants, which is critical for downstream analyses such as PCR, sequencing, and gene expression studies.
Overview
DNA and RNA Sample Extraction
DNA and RNA samples are often obtained from crude preparations. Genomic DNA, plasmid DNA, and total RNA can be extracted and purified from a variety of sources including bacterial and mammalian cells, plant tissue, fungal tissue, mammalian tissue, blood, plasma, serum, viruses, buccal and nasal swabs, gel matrices, PCRs, and other enzymatic reactions. Isolation of nucleic acid from these samples often involves the lysis of cell membranes or sample homogenization, followed by the removal of proteins, enzymes, detergents, salts, and lipids.
Common DNA and RNA Extraction Approaches
- Alkaline extraction
- Phenol-chloroform extraction
- Cesium chloride (CsCl) density gradient centrifugation
- Oligo(dT)-cellulose chromatography
- Silica matrice
- Glass beads
- Diatomaceous earth
- Anion exchange chromatography
- Size exclusion chromatography
Downstream Applications
The final application will dictate the best method for purification. Downstream applications include:
- PCR
- qPCR
- Restriction digests
- Ligation
- Cloning
- Genotyping
- Gene expression analysis
- Next-generation sequencing (NGS)
- Northern and Southern blotting