General virology and lab diagnostic methods Flashcards
In what form do viruses contain nucleic acids?
In the form of linear or circular RNA in a single strand (most RNA viruses) and DNA in a double strand (most DNA viruses) in a (+) or (-) sense direction
What is the nucleic acid typically surrounded by? What is this made of?
Protein coat (caspid), made of subunits that form a helical, icosahedral or complex structure
What may nucleic acid complex with?
Nucleoprotein
Describe uneveloped viruses
- Typically resistant to acid and desiccation
- Typically cause infection via the oro-faecal route
What size are viruses?
Mostly 20-300nm
Are viruses visible by light microscope?
No
What is the viral envelope derived from?
It is a lipid bilayer derived from the host cell
What determines the Baltimore classification of the virus?
Nucleic acid type (and replication strategy)
What are methods of detecting virus or virus fragments in the blood or CSF?
ELISA
PCR (or RT-PCR)
Plaque (or other infectious centre) assays
Hemagglutination
What are methods for detecting specific antibody?
ELISA, hemagglutination inhibition
Baltimore class I
Double-stranded DNA viruses
Baltimore class II
Single-stranded DNA viruses
Baltimore class III
Double-stranded RNA viruses
Baltimore class IV
Single-stranded RNA viruses - postive-sense
Baltimore class V
Single-stranded RNA viruses - negative-sense
