Suckling mice is used for isolation of

It is necessary to employ suckling mice for the isolation of coxsackieviruses.  Inoculation is usually made by intracerebral, subcutaneous and intraperitoneal route.  Adult mice are not susceptible.  Human diploid fibroblasts (HDF) cell line is used for cultivation of coxsackie A7,9,16; CMV; Echovirus; enteroviruses; HSV-1,2; Poliovirus: parainfluenzavirus, rhinovirus and VZV. Cultivation of viruses ‘As viruses are obligate intracellular parasites they cannot be grown on any inanimate culture medium.' Three methods are employed for cultivation of viruses : 1. Animal Inoculation  Earliest method  Mice are most widely employed animals  Other animals used are guinea pigs, rabbits and ferrets. 2. Embryonated eggs  Sites of inoculation are: a) Chorioallantoic Membrane ------- visible pocks are produced → HSV, Vaccinia, Smallpox b) Amniotic Sac c) Allantoic cavity →  Influenza o Some paramyxoviruses d) Yolk Sac → o Some viruses o Chlamydia o Rickettsia 3.Tissue culture  Most important method for virus isolation.  Three types of tissue culture are available I. Organ Culture II Explant Culture III. Cell Culture - (routinely employed)  Cell culture may be 1. Primary cell culture: Rhesus monkey kidney, human amnion, chick embryo fibroblast, human embryonic kidney. 2. Diploid cell strains:- Human diploid fibroblast HL-8, WI-38. 3. Continuous cell line:- Hela, HEP-2, McCoy, Vero