Viral diagnostic methods
1- Direct detection of virus
A The clinical specimen is examined directly for the presence of virus particles, antigen or nucleic acid. Following is the detection methods that t consider direct detection of virus .
1- Light microscopy .
2- Electron microscopy
3- Antigen detection test such as ELISA
4- Molecular methods, for example PCR and nucleic acid probes
2- Indirect methods (virus isolation)
This method include growing the virus into cell culture, egg or animal
Animal inoculation
Inoculation of eggs
In vitro cell culture
3- Serology detection
This method used to measure the titters of antibody against virus during stages of infection
Light microscopy
Replication virus process often lead to histological change in infected cells such as, inclusion bodies (IB)
Inclusion bodies: are collections of replication virus particles inside the nucleus or cytoplasm of infected cell, such as Negri bodies (see the picture next page).
In tissue culture some viruses able to induce morphological change because virus replication these change called cytopathic effect (CPE) (see the picture next page),
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