DNA purification

Question 1

why is DNA purification important?

Answer 1

-DNA fingerprinting
-genetic screening
-genetic manipulation
-paternity testing
-determining drug resistence

Question 2

describe the steps of DNA purification

Answer 2

-add salt and detergent to water and stir
-crush food sample with pestle and mortar and add it to the mixture
-stand beaker in hot water 60degrees for 15 mins
-cool mixture by standing beaker in icy water
-filter mixture to remove sample tissue
-add protease enzyme to solution
-carefully pour ice cold ethanol to solution

Question 3

why do we use salt and detergent?

Answer 3

salt- makes DNA less hydrophilic, neutralises it, and detaches protein from DNA

detergent- helps break down cell membranes

Question 4

why do we use a hot water bath, cool mixture after and pestle and mortar?

Answer 4

pestle and mortar- break down cellulose cell wall

hot water bath- to denature DNases that might degrade the DNA

cool in ice- so the DNA doesn’t get broken down/ denature from the heat too

Question 5

why do we use protease and ice cold ethanol?

Answer 5

protease- breaks down protein in solution/ histones

ice cold ethanol - to precipitate the DNA