Lecture 7: Molecular Diagnostics

Question 1

How does hybridization work?

Answer 1

ssDNA from patient is bound to complementary DNA/RNA from disease genome
-if match, fluorescent label will appear

Question 2

What is the point of a blotting technique?

Answer 2

To detect specific biomolecules
Southern: DNA
Western: protein
Northern: mRNA
Eastern: post-translational modifications

Question 3

What is PCR?

Answer 3

Amplifying DNA sequence from subject

-uses Taq polymerase

Question 4

What is qPCR?

Answer 4

Can use qPCR to figure out how many cycles of replications happened
-cancer vs normal cells

Question 5

What is restriction fragment length polymorphism (RFLP)?

Answer 5

Specific cuts are made at different nucleotides

-can be used for DNA finger printing, paternity test, mutation diagnosis

Question 6

What is variable number of tandem repeats (VNTR)?

Answer 6

Can look for patterns

ex: Huntington - CAG repeats

Question 7

How do you make proteins?

Answer 7

1) cDNA inserted into expression vectors
2) mixed with plasmid DNA from bacteria
3) in recombinant bacteria - lots of multiplying
4) Extract human insulin

Question 8

How do you produce antibodies?

Answer 8

Mix monoclonal ab with tumor cell to immortalize it

Question 9

What does an indirect Elisa measure?

Answer 9

Amount of antibody

Question 10

What does a direct Elisa measure?

Answer 10

Amount of antigen