Practicals

Question 1

What is RNase A used for?

Answer 1

Degradation of RNA

Question 2

What is the use of glucose when resuspending cells during alkaline lysis>?

Answer 2

Sets the correct osmolarity

Question 3

What is the use of Tris?

Answer 3

pH buffer

Question 4

What is EDTA used for?

Answer 4

Binds to divalent cations to inhibit the action of DNAse enzymes

Question 5

What is the use for SDS?

Answer 5

A detergent that dissolves lipid membrane of cells

Question 6

What is the use of NaOH

Answer 6

Provides alkaline conditions for DNA to be denatured.

Question 7

What is the use for KAc

Answer 7

Neutralises the alkaline conditions which allows for the reannealing of plasmid DNA

Question 8

What happens after the addition of ethanol to a solution containing potassium acetate.

Answer 8

Precipitation of plasmid DNA

Question 9

What is required for PCR?

Answer 9

Plasmid DNA (template), oligonucleotide primers, Taq polymerase (heat stable), nuclotide triphosphates, divalent cation containing buffer.

Question 10

What are the steps of PCR?

Answer 10

1) Heating at 94 degrees to denature DNA
2) Cooling to 50-60 degrees to allow primer annealing
3) Heat to 72 degrees for optimum Taq polymerase activity
4) repeat