Diagnosis of Viral Disease (3)

Question 1

What are some benefits of PCR?

Answer 1

Precise

Can amplify or copy a specific DNA target from a mix of DNA molecules

Question 2

3 official steps of PCR?

Answer 2

1) Denature - heat separates 2 strands of single stranded DNA
2) Anneal - 2 primers added and attach to ends of DNA segment
3) Extention/Elongation - Taq polymerase keeps adding fre nucleotides to attached primer

Question 3

How many new DNA molecules are obtained from the original one in PCR?
How many cycles does one PCR go through?

Answer 3

• 2 (each has 1 old strand and 1 new)

- 30 to 40 cycles

Question 4

a Target Speficic Probe or intercalating dyes are used in this diagnosis method

Answer 4

qPCR (aka Real time PCR or Quantitative PCR)

Question 5

T/F: there is a different color code for each base when doing genome sequencing.

Answer 5

True

Also, use fluorescent dyes

Question 6

What are some advantages of NGS (Next generation sequencing), especially when compared to Sanger method?

Answer 6

cheap
quick
requires less DNA
more accurate and reliable
high throughput

Question 7

Define Metagenomics

Answer 7

studying collective set of microbial populations

Question 8

Steps of metagenomics

Answer 8

sample (metagenome) –> DNA reads –> sequence comparison (reference databases) –> comparison data –> interactive analysis and visualization

Question 9

Define Phylogenic Analysis

Answer 9

studies evolution of viruses and genetic relationship of viruses

Question 10

Describe Microarray

What is its advantage?

Answer 10

• known chip with DNA of 3 viruses (1 in each hole)
• fluorescent dye binds to some holes (+) –> virus of unknown sample interacting with virus of known sample leads to (+)
• no fluorescence = (-)

-Advantage: hundreds of pathogens can be screened for simultaneously using a single microarray chip