The DNA is the genetic material of all living organisms. Within this master molecule,Whether double stranded or single stranded, all the information necessary to create and direct the chemical machinery of life is found. Before being able to study DNA in the context of a university research laboratory, of medical analyses or of criminal investigations, scientists must be able to extract it from the tissue in which it is contained.So this article is going to help many curious scientists to be able to extract their own DNA and conserve it without distortion
This method can be used to extract the DNA of other stuff like onions,banana,green leafy vegetable etc.The process is the same except for the primary extraction which involve getting an extract of DNA from the organism.
Materials needed for DNA extraction.
- Test tube with tight fitting lid
- Lab scoop or spatula or teaspoon
- Isopropyl or ethyl alcohol (at least 70% concentration, higher is better—we used 95%)
- Plastic bulb Pipette
- Clean Paper cup or plastic cup
- Safety goggles
- Lab Jacket
- A pair of Gloves
- Sodium chloride (salt)
- Distilled or bottled water
- Liquid dish soap or hand soap (Detergent)
- Stir rod
- Small glass vial
Principle of the Saline-Detergent-Alcohol Method for DNA Extraction
- The saline solution help in clumping the DNA together.
- The degreasing agents (Restricted enzymes ) in the liquid soap or detergent help to break down the cell membrane in order to release the DNA trapped inside the cell’s nucleus.
- By gently mixing the soap and mouthwash solution,this avoid breaking up the DNA clumps too much.
- The clump DNA strand is not soluble in alcohol hence precipitated out where the liquid layers meet.
- Into a clean beaker,create a salty or saline solution by adding 2-3 teaspoon of Sodium chloride (Table salt) into approximately 25 ml of distilled water or bottle.
- Now stir the solution until the salt is completely dissolved.
- Pour the saline solution into a clean plastic or paper cup.This will be our mouthwash solution
N.B : This experiment involves extracting DNA from the mouth hence it is best to do this with a clean mouth that is after lunch to avoid contamination or undesirable particles.
- Drink without swallowing a mouthful of the saline solution from the plastic or paper cup swishing it back and forth for at least 30 – 45 seconds scraping your teeth along the inside of your cheeks as you do during mouth washing.This process detach DNA strand from your mouth,cheeks,tongue etc
- Spit or pour back the mouth washed solution into the plastic cup
- Transfer the mouth washed solution into a clean or sterile test tube until it fills about one-half inch of the bottom of the clean test tube.
- Carefully add two drops of the detergent or liquid soap into the test tube using a plastic bulb pipette.
- Tilting the test tube approximately 45 degrees, then add about 15 – 20 drops of alcohol making sure it slides down the test tube without disturbing the solution.
Alcohol is less dense hence will will sit atop the mouthwash and the liquid soap solution making three layered solution in the test tube.
- Tightly put the cap on the test tube then carefully and gently mix the solution taking care not to make bubbles in the test tube.You can do it by gently tilting the test tube upside down then right side up at least three times.
- In an upright position,allow the test tube sit undisturbed for one minute. At this point, you should begin to see a milky white thread, possibly interspersed with bubbles,this will appear between the solution and the alcohol. Voila! That’s your DNA! After several minutes, the DNA should be suspended in the alcohol layer.
- You can now gently insert your stir rod into the solution and wind your DNA around it and make a wet mount for microscopic observation
- You can also preserve your DNA by carefully scraping it into a small vial with a few drops of alcohol then stored in the freezer as long as you wish.
We’ll love to see and answer your numerous comments and Questions!