Question

Discuss the medical need for viral cultivation and give examples of two in vivo and one in vitro method. Define the term pocks and plaques.

Answer 1

Virus require host to grow and for their survival. The main purpose to perform viral cultivation is to look at the viral structure, replication ,genetics and their effects on the cell, prepare viral based vaccines and identifying virus in clinical samples.

To look at their effect in vivo , one can directly administer viral particles cultured in a particular media can be injected into animal to look at various immune repsonses undergone by the animal/ viral replication mechanism. One can also inject them into the embryonated egg to look at their effects in terms of genetics, reproduction, allantoic activity, (say for mumps and influenza virus). Other method includes using cell culture to grow them, to look at their ability to affect a particular function or grow them indefinitely (continuous cell lines).

A viral plaque is a visible structure formed either within a cell culture both mammalian and bacterial in a nutrient medium. Pocks on the other hand are visible foci or lesions on chorioallantoic membrane of chick embryo.