IVRI, Bareilly, U.P., India.
Fowl pox virus cannot be growing in non-living medium and they replicate only inside-living cells (CEF and Duck Embryo Fibroblast). This virus only possesses genome (DNA), which is covered with protein coat. In some viruses, protein coat is covered by anther layer, the envelope, which derived from host cells membrane. As viruses do not have nucleus, mitochondria, golgi apparatus and other cellular components, they are totally dependent on cells for macro-molecular synthesis and therefore, out side the living cells they become totally inert. For isolation of the virus from the clinical sample, inoculation in to the natural host is best, as it is most sensitive and natural method of producing the virus. But isolation in natural host or in even laboratory animals is generally avoided due to aesthetic reasons and therefore, virus isolation/cultivation in cell culture system is preferred as this avoids use of live animals and also produces high titres of the virus. For cultivation of fowl pox virus in cell culture system, all the glassware, media and other reagents needed should be sterilized before use to avoid microbial contamination.