To isolate DNA from a plant tissue

Question 1

Step 1

Answer 1

Add sodium chloride to a small vol. of washing liquid dissolved in water
(salt causes DNA molecules to clump together, cell dissolved by WU liquid)

Question 2

Step 2

Answer 2

Chop an onion into small cubes, add to beaker and stir
(Allows washing up liquid to reach more cells)

Question 3

Step 3

Answer 3

Put the beaker in a water bath at 60º for 15mins

Question 4

Step 4

Answer 4

Place beaker in an ice water bath for 5 mins (frequently stir)
(Temp denatures enzymes)

Question 5

Step 5

Answer 5

Pour into a food blender and blend for 3 secs at high speed
(Slows down the breakdown of DNA)

Question 6

Step 6

Answer 6

Pour mixture into blender for 3 secs on high speed
(Breaks down the cell walls and releases DNA)

Question 7

Step 7

Answer 7

Filter the mixture through coffee filter paper
(Cell parts retained in coffee filter paper)

Question 8

Step 8

Answer 8

Use syringe without a needle to place some of the onion filtrate into a boiling tube

Question 9

Step 9

Answer 9

Add a few drops of protease enzyme to the tube and stir
(protease breaks down the proteins around the DNA)

Question 10

Step 10

Answer 10

Pour freezing cold ethanol carefully down the side of the boiling tube
(Alcohol removes water from DNA, DNA forms white threads)

Question 11

Step 11

Answer 11

Gently twist a small glass rod/wire loop in alcohol