Viral total RNA extraction - Spin-column
There are different types of spin-column purification material : Glass fiber, derivatized silica, or ion exchange membrane in column
Samples are lysed and passed through the membrane using centrifugal or vacuum force. Wash and elution solutions are subsequently passed through the membrane, and the sample is collected into a tube by centrifugation or vacuum.
Solid phase extraction such as using a spin-column based extraction method takes advantage of the fact that DNA binds to silica. The sample containing DNA is added to a column containing a silica gel or silica beads and chaotropic salts. The chaotropic salts disrupt the hydrogen bonding between strands and facilitate of the DNA to silica by causing the nucleic acids to become hydrophobic. This exposes the phosphate residues so they are available for adsorption. The DNA binds to the silica, while the rest of the solution is washed out using ehtanol to remove chaotropic salts and other unnecessary constituents. The DNA can then be rehydrated with aquaeous low salt solutions allowing for elution of the DNA from the beads.
The advantages of this type of methods are the convenience, the ease of use, the throughput flexibility and the ability to automate.
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