lecture 4: DNA Profiling

Question 1

How to extract DNA? step 1

Answer 1

1) Breaking up the cells (manually crushing). Separates the cells and exposes them to the soap and salt
2) Adding soap helps to break down the cellular and nuclear membranes to release the DNA
3) Adding salt causes DNA to bind together
4) Filtering off the debris (using a filtering device)
5) Protein framework of the chromosomes removed (adding protease)
6) Adding ethanol helps the DNA precipitate

Question 2

How to extract DNA? step 2

Answer 2

1) Gel Electrophoresis allows you to separate nucleotides based on size
2) DNA fragments are different sizes
3) DNA fragments are negatively charged because of the phosphate group (move towards positive because of electric field)
4) Shorter fragments move faster than longer fragments

Question 3

uses of gel electrophoresis

Answer 3

Criminal cases
Paternity cases
Comparing species for classification purpose
Medical diagnosis
Identifying human remains
Animals and plant breeding