Send us your questions

Some of our visitors have sent emails with interesting questions, we decided to start having a space to answer them. In this space the blog "Restless Minds" will answer all questions you send us
Send us your question for the email: Restless Minds.

Science progress affects our daily life and "to know" means you are going to chose right, because it allows you to form your own opinion on scientific everyday issues. On the other hand, having an elegant and harmonious vision of the world where we live in leads to a feeling of intellectual satisfaction.
We believe this kind of scientific day to day knowledge should be encouraged from an early age, and that's why this project was born: science, culture, knowledge, crafts for your restless mind.

Friday, February 10, 2012

DNA extraction from onion cells

DNA, or deoxyribonucleic acid, is the hereditary material in almost living "things".
Nearly every cell in a person’s body has the same DNA. Most of DNA is located in cell nucleus. We can say this DNA is like a stepladder and it can be as long as 1,80m but it can fold itself so tight it can be stored in a small space with micro dimensions.

Lets see how we can see this DNA without any microscopy help.

We need:
  • 2 bowls, one of them must be transparent,
  • a knife,
  • a onion,
  • dish detergent,
  • salt,
  • water,
  • 2 spoons,
  • alcohol.
How to:
  1. Peel the onion;
  2. Cut the onion, into small pieces, to the bowl;
  3. Add some dish detergent, enough to cover it;
  4. Add the salt (1/2 tablespoon);
  5. Finally add the water (2 tablespoons);
  6. Mix, careful, we don't want it to form bubbles;
  7. Wait 20 min;
  8. Mix again;
  9. Separate the liquid layer from the rest, the DNA is on the liquid, reject the rest.
  10. Add alcohol to the liquid, slowly, we want the alcohol to form a second layer above the liquid, try to make the alcohol run down the bowl wall.
  11. Don't mix the layers;
  12. Wait another 20 min.
What happens?
You can see small white strands; some of them may look like small clusters.

Why?
DNA precipitates when mixed with alcohol; this means it's not soluble in this reagent. This causes the DNA to clump together when there is a lot of it. And, usually, cells contain a lot of it!

NOTES:
Salt- Helps DNA to precipitate
Cold water- Helps to maintain DNA intact. If we use hot water cellular enzymes can destroy the DNA strand.







Et voil√°!
Genetic in your kitchen!

Enjoy!

No comments:

Related Posts Plugin for WordPress, Blogger...