Extracting DNA practical (kiwi)

Question 1

What are the steps of the method to extracting DNA from a kiwi?

Answer 1

1. mash the kiwi as much as you can
2. make extraction buffer by adding detergent
3. add salt and tap water
4. stir until salt is dissolved
5. add mashed kiwi to extraction buffer
6. incubate the mixture at 60’C for 15 min
7. filter the mixture using a sieve
8. slowly add ice-cold ethanol
9. leave the mixture for a few minutes
10. Take out DNA using a wooden splint- should look fluffy and in threads

Question 2

Why do you need the ethanol to be ice-cold?

Answer 2

-help precipitate the DNA out of the solution

Question 3

Why do you add detergent?

Answer 3

-cell membrane is made of phospholipids (fat) and the detergent emulsifies these to allow the membrane to be disturbed

Question 4

Why do you mash the kiwi?

Answer 4

so the extraction buffer can work quickly on a large surface area

Question 5

Why do you incubate the mixture?

Answer 5

the heat helps to disrupt the cell membrane and proteins within the cell

Question 6

Why do you add salt?

Answer 6

To get the DNA to stick together

Question 7

Why do you add ethanol?

Answer 7

DNA can’t dissolve in ethanol so it precipitates out