Kiwi Fruit Experiment: Finding the DNA of a kiwi fruit - Think like a scientist (10/10)
Summary
TLDRThis video script demonstrates a simple kitchen experiment to extract DNA from a kiwi fruit, illustrating the concept of DNA as the blueprint of life. Using household items like salt, water, washing up liquid, and ice-cold alcohol, viewers learn to break down cells, create an extraction buffer, and observe DNA strands forming at the liquid interface. The process highlights the accessibility of scientific exploration and invites participants to an online discussion for further insights into DNA's role and significance.
Takeaways
- 𧬠DNA is the 'blueprint of life' and is present in all living cells, including humans.
- π DNA is invisible to the naked eye and requires special methods to observe it.
- π₯ A simple kitchen experiment can be conducted to extract DNA, using a kiwi fruit as an example.
- π Alternative fruits like onions, strawberries, or even defrosted peas can be used for DNA extraction.
- π₯ Ice-cold alcohol, such as methylated spirits, vodka, or strong white rum, is needed for the extraction process.
- π§βπ³ The fruit's skin should be removed as it contains less DNA and is mostly dead.
- πͺ Chopping and mashing the fruit helps break up cells and increase the surface area for DNA extraction.
- π§ͺ A mixture of salt, water, and washing up liquid forms an 'extraction buffer' that aids in cell breakdown and DNA preservation.
- π Warming the fruit mix in lukewarm water for 15 minutes helps to further release DNA.
- π The DNA can be made visible by straining the fruit mix and adding ice-cold alcohol, which causes the DNA to form visible strands.
- π¬ The DNA appears as tiny white strands and filaments, which can be extracted using a paper clip.
- π¬ The script encourages viewers to join an online discussion to learn more about DNA and its importance.
Q & A
What is DNA commonly referred to as?
-DNA is commonly referred to as the blueprint of life.
Where is DNA found?
-DNA is found in all the cells of all living things, including humans.
What is the purpose of using ice-cold alcohol in the experiment?
-Ice-cold alcohol is used to separate the DNA from other substances because it is less dense and will float over the surface of the kiwi mix.
What can be used as a substitute for methylated spirits in the experiment?
-Vodka or very strong white rum can be used as substitutes for methylated spirits.
Why is the skin of the kiwi fruit removed before the experiment?
-The skin of the kiwi fruit is removed because it is mostly dead and does not contain much DNA.
What is the role of the extraction buffer in the DNA extraction process?
-The extraction buffer, made of salt, water, and washing up liquid, helps to break up the cells further and prevents the DNA from degrading.
How does mashing the kiwi fruit contribute to the DNA extraction?
-Mashing the kiwi fruit breaks up the cells and increases the surface area from which DNA can be extracted.
What is the purpose of warming the kiwi mix in lukewarm water?
-Warming the kiwi mix in lukewarm water helps to release more DNA from the cells.
How long should the kiwi mix be left in the warm water?
-The kiwi mix should be left in the warm water for 15 minutes to allow for the release of more DNA.
Why is the alcohol poured gently down the side of the glass during the experiment?
-The alcohol is poured gently down the side of the glass to allow it to float over the surface of the kiwi mix, facilitating the visualization of DNA.
How can you tell when the DNA is being extracted from the kiwi mix?
-The presence of tiny white strands and filaments forming at the join between the alcohol and kiwi mix indicates that DNA is being extracted.
Outlines
𧬠DNA Extraction from Kiwi Fruit
This paragraph introduces the concept of DNA as the blueprint of life and suggests a simple kitchen experiment to visualize DNA. The speaker plans to extract DNA from a kiwi fruit, but mentions that other fruits or even defrosted peas can be used. The process requires ice-cold alcohol, such as methylated spirits, vodka, or strong white rum, and a fine sieve or coffee filter paper. The speaker begins by peeling and mashing the kiwi to break up the cells, then mixes salt, water, and washing up liquid to create an extraction buffer that helps to further break up the cells and prevent DNA degradation. The mixture is warmed to release more DNA, and after straining, the addition of ice-cold alcohol causes the DNA to become visible as white strands and filaments, which can be extracted using a paper clip.
Mindmap
Keywords
π‘DNA
π‘Cells
π‘Extraction
π‘Methylated Spirits
π‘Sieve
π‘Salt
π‘Washing Up Liquid
π‘Buffer
π‘Mash
π‘Lukewarm
π‘Alcohol
Highlights
DNA is referred to as the blueprint of life and is present in all living cells.
A simple kitchen experiment can make DNA visible.
DNA extraction can be performed using a variety of fruits or vegetables.
Defrosted frozen peas can be used if fresh produce is unavailable.
Ice-cold alcohol, such as methylated spirits, is required for the experiment.
A fine sieve or coffee filter paper is needed to strain the mixture.
Peeling the fruit is the first step to avoid extracting DNA from the dead skin.
Mashing the fruit breaks up cells, increasing the surface area for DNA extraction.
An extraction buffer is made by mixing salt, water, and washing up liquid.
The buffer helps to further break up cells and prevent DNA degradation.
Warming the kiwi mix in lukewarm water aids in the release of more DNA.
Straining the kiwi mix separates the liquid containing the DNA.
Ice-cold alcohol is gently poured to reveal the DNA strands at the liquid interface.
Tiny white strands and filaments visible in the alcohol are the extracted DNA.
DNA can be physically extracted and observed with a simple paper clip.
The experiment demonstrates DNA as the blueprint of life in a tangible way.
Further information and discussion about DNA can be found in the online resources provided by the Open University.
Transcripts
You've probably all heard of DNA. It's usually referred to as the blueprint of life.
Now DNA is in all the cells of all living things, including ourselves.
But it's kind of difficult to comprehend because you can't see it.
Well it turns out that with a very simple
kitchen experiment, you actually can see DNA.
And that's what we're going to do now.
I'm going to extract the DNA from this kiwi fruit.
Now it doesn't have to be a kiwi. You can use an onion, or strawberries.
Raid the fruit bowl and pick what you fancy. You can even use defrosted
frozen peas if you haven't got anything fresh.
You're also going to need some ice cold alcohol.
I'm using methylated spirits, and it needs to be in
the freezer for half an hour before you start the experiment.
You could try something like
vodka or very strong white rum as well.
And you're going to need a fine sieve, or you could use coffee filter paper. I'm just
using a tea strainer.
The first thing I'm going to do
is peel the skin off the kiwi. And that's because it's mostly
dead, and it hasn't got very much DNA in it anyway.
So now I'm going to chop it up into small pieces.
And then I'm going to start mashing
it. This is to start breaking up the cells and to give us
a bigger surface area to extract the DNA from.
The next thing you need to do, is mix together
two grams of salt with 100 millilitres of water.
Add this to five gram of washing up liquid.
So mix the three things together. Try and do it quite gently because
you don't want loads of foam and bubbles.
But you do need to stir until the salt's dissolved.
This is called an extraction buffer.
It doesn't really matter about the terminology. It's
basically going to help to break up the cells even further,
and stop the DNA from degrading.
Next you're going to
add this to your kiwi mix.
Keep mashing because the more you mash, the more DNA you will get.
The final step is just
to warm up the kiwi mix. To do that, I'm just
using a bowl of warm water. I've used boiling water from the kettle, added
some cold, so it's lukewarm. I'm going to leave that
sitting in there for 15 minutes. And again, this is just to help release more of the DNA.
Well that's the 15 minutes up. The next thing is to strain the kiwi mix.
Oh, I'm spilling a bit of it.
Now this lovely green liquid has got our kiwi
DNA in it. But we still can't see it, which is where the
alcohol comes in.
Well that's well and truly ice cold. Now pour
the alcohol very gently down the side of the glass. It
should float out over the surface of the kiwi mix because it's actually less dense.
You need to look very carefully at the join between the two liquids, and you'll see tiny
white strands and filaments forming. That's the kiwi DNA.
And I can just very carefully use a paper clip to start
hooking come of it out.
And that is DNA. The blueprint of life.
Now to find out more about
DNA-- what it does and why it's important-- you
need to join in with the online discussion.
Get More from the Open University
Check out the links on screen now.
5.0 / 5 (0 votes)