DU-50 Genomic DNA Extraction Kit cells, tissues, blood
Choosing the correct DNA extraction kit can save crucial time in optimizing and running the experiment. Factors to consider when selecting a kit include:
Sample Origin: Different kits are used to extract material from specific sources, including human tissue, blood, hair, rodent tissues, leaf tissue, bacteria, yeast, fungi, insects, faeces, body fluids, spores, soil, samples clinical (eg, biopsy specimens, fine needle aspirates), forensic specimens (eg, dried blood drops, buccal swabs), and fingerprints.
Preparation method: Sample preparations can be: fresh or previously frozen cell pellets, formalin-fixed or paraffin-embedded tissue sections, frozen tissue sections, ethanol-fixed cells, Oragene® preserved samples and samples from forensic sources. that can contain very little material
Intended use: the quality and purity of the DNA provided by the kit should be suitable for the intended subsequent application, which could be sequencing, fingerprinting, PCR, quantitative PCR (qPCR), Southern blotting, random amplification of polymorphic DNA (RAPD), Amplified fragment length polymorphism (AFLP) and restriction fragment length polymorphism (RFLP) applications, restriction endonuclease digestion or preparation of shotgun libraries.
Humic content: If the sample has humic content such as compost, sediment and manure, a kit/method should be used that removes humic substances as they can inhibit downstream applications such as PCR.
Sample quantity: The kit to use depends on the size of the sample being analyzed. For example, the number of cultured mammalian cells (105-107) and bacterial cells (106-1011), the weight of human tissue, plant tissue or soil, the volume of blood or even traces of DNA samples from the scene of the crime.
Yield: the desired or expected amount of DNA to be purified from the sample. This depends on the sample and subsequent applications.
Simplicity: the operation of the kit depends on the user experience and the desired degree of control over each stage of the sample processing.
Silica-based technology
Silica-based technologies are widely used in current kits. DNA is specifically adsorbed on silica membranes/beads/particles in the presence of certain salts and at a defined pH. Cellular contaminants are removed by washing steps. The DNA is eluted in an elution or low salt buffer. Chaotropic salts are included in the kit buffers to aid in protein denaturation and DNA extraction. This method can be incorporated into spin columns and microchips are cost-effective, has a simpler and faster procedure than organic extraction, and is suitable for automation. Kits based on this method include Thermo Fisher’s Purelink Genomic DNA Extraction Kit and QIAGEN’s DNeasy Blood and Tissue Kit.
Magnetic separation
Magnetic separation relies on the reversible binding of DNA to a magnetic solid surface/bead/particles that have been coated with a DNA-binding antibody or a functional group that specifically interacts with DNA. After DNA binding, the beads are separated from other contaminating cellular components, washed, and purified DNA is eluted by ethanol extraction. This method is quick, easy to perform, and can be automated. However, it can be more expensive than other methodologies. Examples of commercially available kits include the Agencourt DNAdvance kit from Beckman Coulter) and the Geneaid Magnetic Bead Genomic DNA Extraction Kit.
Anion exchange technology
DNA extraction by anion exchange chromatography is based on the specific interaction between negatively charged phosphates of the nucleic acid and positively charged surface molecules on the substrate. DNA specifically binds to the substrate in the presence of low salt content, contaminants are removed by washing steps using a low or medium salt buffer, and purified DNA is eluted using a high salt buffer. This technology is most commonly used in plasmid isolation kits, such as Thermo Fisher’s PureLink HiPure Plasmid DNA Purification Kits, QIAGEN and Genomic-tip Plasmid Mini / Midi Kits, and NucleoBond PC Kits from Macherey Nagel.
Others
Other DNA extraction methods include salting, caesium chloride density gradients and helix 100 resin. DNA isolation methods are often modified and optimized for different cell types or sample sources. For example, cetyltrimethylammonium bromide (CTAB) and guanidium thiocyanate (GITC) is often included in protocols for the extraction of DNA from plant materials and are discussed in more detail in “Extraction of DNA from plant tissue and cells”.
