Does a banana have DNA?
Yes, it sure does. Like all living things, a banana has a unique set of DNA, and today we're going to see what it looks like. Get ready to do some DNA extracting!
Introduction
All living things are made up of cells, and within the nucleus of each cell is a stringy substance called DNA, which stands for deoxyribonucleic acid. DNA contains the biological instructions that make each species and each of us unique.
We can't see a single cell or the DNA inside it with our eyes - scientists need very powerful microscopes and other equipment to do that. But we can extract DNA from millions of cells, and view it without a microscope. Let's have a go!
What you need
* Banana
* Water
* Detergent
* Methylated spirits, chilled
* Small disposable plastic narrow container, preferably with lid.
What to do
1. Blend half the banana with 1?2 cup of water until smooth.
2. Half fill your container with the banana mixture (you may not need all of it).
3. Add around 10 drops of detergent to the banana mixture.
4. Put on the lid and gently shake the container (this will break open the cells and release the DNA).
5. Carefully pour around 20 to 30mls of the chilled methylated spirits (also known as denatured alcohol) into the banana mixture. The methylated spirits should sit on top of the banana mixture.
6. Let the mixture sit for a few minutes; you should soon see whitish material forming between the two layers of liquid. This is banana DNA! Use a toothpick to fish out the gooey strands and look at them under a microscope, if you have one.
What's happening?
The banana is made up of millions of cells which contain DNA. To release the DNA, we need to break down the plant matter, then break open the cell.
Squashing or pureeing the banana takes care of the first breaking down stage. Adding the detergent then helps to break down the outer membranes of the cells, and, in doing so, releases the DNA.
