Purification of DNA by Precipitation

Question 1

What are the steps to purify the DNA of a strawberry?

Answer 1

1. break open cells by putting strawberry cells in blender
2. mix together washing up detergent, table salt and distilled water
3. mix in cell mixture and wait (10 mins)
4. keep ice cold
5. filter mixture
6. slowly pour ethanol to form layer on top
7. wait (10 mins)
8. DNA forms white percipitate
9. Remove DNA

Question 2

What is the washing up detergent for?

Answer 2

divide + clump together pieces of cell membrane

Question 3

What is the table salt (NaCL) for?

Answer 3

clumps together pieces of DNA

Question 4

Why should the cell mixture be ice cold?

Answer 4

to stop enzymes breaking down DNA

Question 5

Why should you filter the mixture?

Answer 5

to remove cell debris + whole cells