DNA extraction

Many diagnostic processes involving detection of bacteria as well as viruses usually begin with DNA extraction. Similarly, diagnosis of various genetic diseases often involves DNA extraction.

What is the process of DNA extraction?

Well, of course, for the process to begin there has to be something that has DNA. Given that anything alive has DNA, as it is the life’s blueprint, everything alive is likely to offer a good sample for DNA extraction. This may be a green pea, kales leaf, or a piece of fresh meat. Other viable sources for DNA extraction include spinach, a chicken liver, and strawberries. Other options include: your toe or the bugs obtained from the backyard. The list is long.


DNA extraction process begins with breaking open or lysing of the cell or the virus from which the DNA is to be extracted. This often involves sonication or beating of the sample. However, a blender will do a lot in enabling this process. Simply put the sample into the blender’s jar and blend for 15 seconds. This will help in separation of the pea cells much easier than having to go through the pounding process. The by-product of this process is a thin sample strip. Straining is useful in obtaining the final sample.


The next process of DNA extraction involves breaking down of the protein-based cellular walls, which is often done by addition of detergents like SDS. The detergents help in removal of the lipid walls. The mixture containing the sample and the detergent is swirled in order to effectively mix. A pinch of enzyme is then added into the test tube and stirred gently to make the DNA clearer and easy to view. Stirring hard breaks down the DNA and make it difficult to view. Meat tenderizers can be used as enzymes. Degradation of DNA linked proteins and cellular proteins can be degraded by addition of proteases.


Precipitation is also a process in DNA extraction. Protein’s precipitation is assisted by addition of salts, for instance, ammonium acetate. For samples that are vortexed using phenol-chloroform and later centrifuged, the proteins remain in organic stage and can be carefully extracted.  The DNA is obtainable from at the interface in between the two phases. DNA is also precipitated by mixing it with alcohol and centrifuging it. The DNA being insoluble will emerge from the resulting solution which contains the earlier added salts.

The resulting DNA pellet is obtained by pouring off the alcohol and drying it. Later, it can be re-suspended into a buffer like Tris. The DNA often appears as a lengthy, stringy molecule. This brings to end the DNA extraction process.