L4

Question 1

How do we detect polymorphisms?

Answer 1

By comparing a DNA sequence to the same sequence in a “reference genome”

Question 2

How to detect genetic variability

Answer 2

1. Isolate DNA from cells or tissue
2. Find the reference genome for humans
3. Make lots of copies via PCR
4. Sequence the DNA and compare it to reference genome

Question 3

What are the 3 steps of PCR?

Answer 3

1. Denaturation 95ºC (breaks apart 2 strands of the DNA template)
2. Annealing 55-66ºC (primers find and bind to their location on templates)
3. Synthesis 72ºC (Taq polymerase catalyzes elongation by adding nucleotides to the primer)

Question 4

What do you need for PCR?

Answer 4

1. Template (isolated DNA)
2. DNA primers
3. Free dNTPs
4. Taq polymerase

Question 5

Agarose gel electrophoresis

Answer 5

• gel is placed in a reservoir filled with electrophoresis buffer and connected to electrodes
• b/c DNA is negatively charged, it will migrate through the pores of the gel toward the anode.
• The further the DNA gets down the plate, the smaller it is