Viral Assays

Question 1

What does EM allow to analyse of the virus?

Answer 1

Virus shape and structure

Question 2

Features of TEM

Answer 2

Thin slices
2D image
Chemical fixation

Question 3

Features of Cryo-EM

Answer 3

Flash freezing
Performed within vaccum of microscope

Question 4

Features of SEM

Answer 4

3D image of surface
Lower magnification than TEM

Question 5

What does confocal microscopy allow for the visualisation of virus

Answer 5

Location within the cell

Question 6

What microscopy allows for real time live cell images?

Answer 6

Confocal microscopy

Question 7

What test uses the viruses antigen?

Answer 7

Lateral flow test / ELISA

Question 9

What does PCR do?

Answer 9

Polymerase chain reaction amplifies regions of DNA

Question 10

What does rt-PCR?

Answer 10

Reverse transcription amplifies regions of RNA

Question 11

What does q-PCR do?

Answer 11

Quanitative so you can work out how many virus genome you start/finish with

Question 12

What is a problem with q-PCR?

Answer 12

Need to know bp sequence to generate PCR primer, but need to be sequenced to know the genome

Question 13

How does a plaque assay work?

Answer 13

Infect cells in a well.
Apply gel layer, limits infection to 2D
Allow several infection cycles
Stain for living cells
Count areas of dead cells

Question 14

What must a virus produce to be able to create a plaque assay?

Answer 14

Cytopathic effect, which is a visual way of seeing cell infection.

Question 15

What is TCID-50?

Answer 15

50 percent tissue culture infectious doseH

Question 16

How is a TCID-50 performed?

Answer 16

Infect cells at different virus diltuions
Allow virus for several infection cycles
Stain for living cells
Couunt wells of dead cells