Today we had one more morning of fun science at the Seinan International School in Fukuoka, organized by Oita University. There were talks about what various researchers do and then we did some hands-on experiments. I showed the students how to get DNA from kiwi and an engineer got them to recreate the workings of a steam engine, using hot water and ice.
All living organisms have DNA, it’s like an instructions book for our makeup. We get it from our parents and, although all (hopefully!) human, each one of us will have slight differences in the code, which makes us unique. This has proven to have a variety of applications, from disease diagnosis to crime solving!
You can watch a demonstration of the DNA extraction protocol here (日本語 こちらです). In case you would like to have a go at home, here is the list of materials:
- soft fruits (such as kiwi or strawberry)
- a (ziplock freezing) bag
- water with 10% washing up liquid
- a bottle or a cup
- kitchen salt and a spoon
- cold alcohol
- a funnel
- coffee filter
- a skewer or a straw
And these are the steps of the protocol:
- Put the fruit in the bag and mash
- Add the detergent to burst the cells that didn’t break up with the mechanical squeezing (this will release their contents, including the DNA)
- To get rid of all the solids, pass this through the coffee filter. At this point, the DNA is dissolved in the liquid, so we can’t collect it.
- Add salt and shake
- Slowly add cold alcohol (more or less the same volume as the liqued you filtered) and don’t shake this time. The alcohol and the salt will precipitate the DNA, so that now we can collect it. Basically, that means now it is all clumped together and solid, so we can fish it out.
- Get a straw or skewer and gently swirl it around in the middle gooey section between the top and bottom liquids (also called phases).
Have fun and please do not drink your experiment! It kind of sounds like a cocktail recipe, but there is detergent in it (and pure ethanol)!!
That last picture was actually the mess, after the experiments were done!