DNA from a Kiwi fruit
Here's how we extract DNA from a kiwi fruit with kids (age 10-15) while explaining what genetics is all about.
- 1/2 kiwi fruit (preferably overripe)
- plastic spoon
- ziploc bag
- pinch of salt
- 2 drops dish (preferably cheap) soap
- clear cup
- coffee filter
- ice cold alcohol or hard liquor (yes, this is a workshop for preteens, openly discuss the dangers involved to the kids)
- plastic fork
Put the kiwi contents in a ziploc bag and squeeze it
How: Empty the juicy contents of the kiwi into a ziploc bag. Close the ziploc bag carefully. Press and squeeze the fruit for a few minutes to turn it into kiwi mush. Don't blow up the bag of kiwi mush!
Why: DNA is in all the cells of the kiwi fruit. We want to get the DNA out of the cells of the fruit. So first we will separate the cells of the kiwi fruit by applying brute force. We also start breaking up some of the cells so that their contents and DNA spills out in the kiwi soup. We preferably use overripe kiwi fruits, since the kiwi contains a protein that breaks apart the cells while ripening, which makes our job to crack the DNA out of the cells' shell easier.
Add a pinch of salts and 2 drops of dish soap and squeeze it some more
How: Open the ziploc bag. Add a pinch of salt. Add 2 drops of liquid dish soap. Close the ziploc bag. Squeeze for a few more minutes.
Why: The dish soap contains molecules that fit in the cell walls and disrupts the membrane structures, spilling out the contents of the kiwi cells into a fine kiwi sap. The salts neutralises the DNA's