Question

List and explain the methods used to identify medically important viruses.

Answer 1

Viruses are first cultivated (by invitro or invivo techniques explained at the last) to isolate and identify virus in the clinical specimen or to prepare vaccines, study the viral structure, replication cycles and their effect on the host cells.

1. Serological Tests: Antibodies are used to identify the virus as seen in neutralization tests, viral hemagglutinations, western blot tests. This is the most common method for identifying the medically important viruses.

2. Studying the Cytopathic effects: Human or animal cell lines are infected with viruses and the visible effects of the infection are observed as changes in the structure.

3. Nucleic acids elucidation: Polymerase chain reaction or sequence DNA-PCR with primers for a specific virus also help in identification of the virus.

Viral cultivation techniques:

In-vitro methods: The cell culture of the infecting single layers of cells like animal or human cell lines are used which permit viral replication. This technique allows closer inspection of the culture for signs of infection.

In-vivo methods: Viruses can also be cultured in eggs containing an embryo which provides intact and self supporting nourishment to the viruses.