DNA Extraction

DNA extraction is one of the basic steps in genetic engineering or modern biotechnology. Biotechnology in anyway is not a new science. Our anscesters have been using biotechnology for thousands of years. Biotechnolgy is any technology involving living organisms or biological products made by those organism. When humans manupulate biological processes within these organisms we call it biotechnology. So this is a very broad area. It has branches in Medicine, Agriculture, Industry and Environment.

Biotechnology over the years have evolved into more sophisticated science and is one of the most talked subjects in the world. No matter what field of biotechnolgy you are involved DNA extraction has same basic principles.

There can be many sources for DNA.

ex:

plant sources: grains, rice germs, plant leafs, any other suitable plant product.

if you want a bulky extract it will be nice to use some thing like strawberry, which gives a high yield.

animal sources: Blood cells (WBC), any other animal tussue.

WBC is taken because it is easy to obtain.

note: When you take a blood sample, there are RBC:WBC in the ratio of approximately 300:1. So first we will have to remove RBC from the sample. To do that RBC are lysed by a freez shock. Then only cells to be remained in the sample are WBCs. But if you are using avian blood samples, there's no need for freeze shock as the RBC of avian blood contain nuclei.

Once we obtained the sample form the source, following have to be done.

1. Remove the cell membranes of the cells and get the intra cellular constituents in to the solution.
2. Degrade the Proteins and cell debris to release DNA
3. Separate DNA from other bio molecules (proteins, AA, ex..)
4. Purify DNA sample

There are many ways to achieve these goals with varying degree of purity to our DNA sample. You can even complete these steps using some of the house hold chemicals. But the purity of the sample will be far less than when you do it in the lab under proper protocols.

Today the theory and the procedures behind DNA extraction, Visualisation of DNA, Electrophoresis of DNA and quantification of DNA sample is done. Tomorrow we will be doing the DNA extraction practical followed by the Electrophoresis of DNA.