how could you extract the dna from these kiwis? what problems might you face?
TRANSCRIPT
Overview
In order to extract DNA from plant cells you need to be able to break through the cell wall and membranes of the
cell
Thinking Points• How can we do this in the
laboratory?• How well will you be able to see the
DNA?
DNA is found in every cell of every living thing,
including kiwi fruit, but the trick is how to get it
out of the cells.
Part of the problem is getting the DNA out of the cells and then you
also have the problem of disentangling the DNA from the protein inside
the cells.
Extracting DNA from cells
Equipment:
-Kiwi fruit-Salt-Washing up liquid-Water-2 x 250cm3 beaker-Knife and white tile-Water bath-Stopclock-Iced water-Ice cold ethanol-Filter paper
Aim: Investigate how to extract DNA from a kiwi
• Safety goggles on
• Hair tied back
• Ethanol is flammable – keep away from naked flame
• You are using sharp knives – be responsible
• Responsible attitude
• Follow instructions on the first time of giving!
Chop up the kiwi fruit and add to the solution you have just made
Chopping the kiwi breaks open the cell. The solution of detergent and salt strips away the cell membrane and
allows the contents to escape
Make a water bath up to 60oCStir the mixture (DONT LET IT
FROTH!)
Put into the water bath for 6
minutes
Drizzle ice cold ethanol down
the inside of the beaker
When you pour the cold ethanol onto the green layer you make the DNA dissolved in the water layer at the bottom turn into a solid, this is because the DNA cannot remain in
solution in ethanol.
DNA Extraction
Complete the cut and stick activity.
The pictures are in order but the instructions aren’t!
When you’ve finished, try the review activity.
Review - What’s inside our nucleus?
1. Label as much of this diagram as you can
2. What words would you associate with genetics other than those you’ve labelled the diagram with?
Back to DNA Discoveries
Try the questions on experiments showing that DNA is the genetic material
.