DNA Extraction

Isolated DNA is needed for genetic testing, body identification, and analysis of forensic evidences. DNA extraction is necessary because all the DNA must be isolated from proteins and other cellular contaminants. Learn how to extract DNA using a buccal swab!

First, we must obtain cheek cells from a person using a buccal swab.
Next, place the buccal swab into an Eppendorf tube. The buccal swab should be filled with thousands of microscopical cheek cells.
Using a micropipettor, add some lysis solution to the tube.
Place into a warm water bath. The lysis solution will now burst open the cell and unravel its DNA.
Now that the DNA is released from the cells, remove the buccal swab from the tube and add a concentrated salt solution into the tube using a micropipettor. This will cause proteins and cellular contaminant to clump together and remove themselves from the DNA.
Place the tube into a centrifuge. The centrifuge will spin the mixture at a high speed, causing the proteins and contaminant to sink to the bottom.
Using a micropipettor, only remove the top layer, which is pure DNA. Do not draw up the proteins and contaminants from the bottom.
Add some isopropyl alcohol to the pure DNA and mix the contents. Since DNA is insoluble with isopropyl alcohol, the DNA will precipitate out and will be visible without the use of a microscope.
Spin the tube in the centrifuge again. This time, the DNA will sink to the bottom of the tube.
Use a micropipettor to extract the pure sample of DNA.

(Source: DNA Extraction)

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