To experimenting something new each day is so much fun. There are plenty of new ideas available on the internet who can keep your students busy doing some exciting stuff every day.
To extract DNA from anything living is being one of the coolest DIY experiments. Even the small children can learn how to extract DNA with the minimum cost and time. In this article, I will give an accessible, step-by-step guide to remove DNA from the living.
For that, first of all we have to find the things which contains DNA. As we know, DNA can be found anything which is living. So, we can take anything for the experiment like Broccoli, Cabbage, or fruits like Banana, Grapes, Tomatoes, etc.
(Note: You can also use Green peas or Chicken liver; but it is not preferable to use the bug you have caught today from your garden. Try to avoid such resources.)
Things we will need –
- Liquid Detergent,
- Pineapple Juice (an enzyme.)
How to extract DNA from anything living?
Step 1: Take a blender and put a half cup of broccoli, a pinch of table salt, and one cup of cold water.
Step 2: Blend them on high for 15 to 20 seconds. The blender separates the broccoli cells from each other. So now, we have a thin and watery broccoli cell soup.
Step 3: Pour that thin broccoli cell soup into another container with the help of a strainer and add two tablespoons of liquid detergent. Mix it well.
Step 4: Let the mixture sit for 5 to 10 minutes and then pour the mixture into test tubes or some other small glass containers, each about 1/3 full.
Step 5: Add a pinch of Pineapple juice (enzymes) to each container and stir gently. Hard stir can break the DNA, so you should be gentle.
Step 6: Pour rubbing ethyl alcohol into the tube so that it forms a layer on top of the pea mixture. Here, take a note that you have to pour until there is the same amount of alcohol in the container as the broccoli mixture.
That’s it! Now we can easily extract DNA. We can use a wooden stick to collect the DNA. For saving the DNA for the future purposes, you can transfer it to a small container filled with alcohol. This technique will protect the DNA.
- DNA is a long, stringy molecule. The salt that you added helps it stick together. We add salt, so the DNA does not dissolve.
- We add alcohol to suspend and protect the DNA. DNA stays typically dissolved in water, but when salty DNA comes in contact with alcohol, it becomes un-dissolved.
- Alcohol is less dense than water, so it floats on the top. We should focus on the white and stringy thing. You can find it between the layers of alcohol and water.
- We add cold water instead of warm water so that the DNA will stay intact while we are extracting it.
- We add liquid detergent because it absorbs lipids and proteins. Moreover, it consumes some membranes and destroys the extra protein layer around the DNA.
- If you don’t have enzyme or even the pineapple juice, you can go for the contact lens cleaning solution. It also helps in protecting the protein layer.
Now that we have successfully extracted DNA from Broccoli, we can try different sources like strawberries or green peas. Try to find out the sources which can give you the most DNA. Use different soaps, shower gels, or detergents and compare the results. You can also try powder detergents.
This experiment converts the learning into a fun learning. Visual and practical activities are always better than the theoretical explanations. Moreover, this lab activity can be done by any child whose age is above 8, and it costs just $1 to $5 per student which is nominal. One can also make his own DNA testing kits for the ease. Just keep trying and experimenting for the better learning.