This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'Which of the following is the primary cell line - \nSelect and explain. \nA. Chick embryo fibroblast, B. Hela cells, C. Vero cells, D. WI-38', 'role': 'user'}, {'content': "Answer: A \nExplanation: Human diploid fibroblasts (HDF) cell line is used for cultivation of coxsackie A7,9,16; CMV; Echovirus;\nenteroviruses; HSV-1,2; Poliovirus: parainfluenza virus, rhinovirus and VZV.\nCultivation of viruses\n‘As viruses are obligate intracellular parasites they cannot be grown on any inanimate culture medium.' Three\nmethods are employed for cultivation of viruses :\n1. Animal Inoculation\n\n\xa0Earliest method\n\xa0Mice are most widely employed animals\n\xa0Other animals used are guinea pigs, rabbits and ferrets.\n\n2. Embryonated eggs\n\n\xa0Sites of inoculation are:\n\na) Chorioallantoic Membrane ------- visible pocks are produced → HSV, Vaccinia, Smallpox\nb) Amniotic Sac\nc) Allantoic cavity\n→ \xa0Influenza \n\xa0 \xa0 \xa0 Some paramyxoviruses\nd) Yolk Sac \n→ Some viruses\n\xa0 \xa0 \xa0Chlamydia \n\xa0 \xa0 \xa0Rickettsia\n3.Tissue culture\n\n\xa0Most important method for virus isolation.\n\xa0Three types of tissue culture are available\n\nI. Organ Culture\nII Explant Culture\nIII. Cell Culture - (routinely employed)\n\nCell culture may be\n\n4. Primary cell culture Rhesus monkey kidney, human amnion, chick embryo fibroblast, human embryonic kidney.\n5. Diploid cell strains:- Human diploid fibroblast HL-8, WI-38.\n6. Continuous cell line:- Hela, HEP-2, McCoy, Vero.", 'role': 'assistant'}]