@article{oai:nagasaki-u.repo.nii.ac.jp:00025181,
 author = {Shameem, Golam Masud Mohammad and Morita, Kouichi and Haishi, Shozo and Igarashi, Akira},
 issue = {4},
 journal = {熱帯医学 Tropical medicine},
 month = {Dec},
 note = {Optimal conditions for the infectivity titration by plaque formation (PFU) of Japanese encephalitis (JE) virus on mammalian BHK21 cells were investigated. Early virus inoculation at 6 hr after seeding low concentration of the cells (0.25×10^5/ml) produced larger and clearer plaques compared with higher concentration or longer incubation (1-2 days) of the cells. However, the virus titer increased by the incubation time until 2 days to become the highest for this inoculum cell concentration, and up to 1 day for the inoculum cell concentration of 0.5 or 1.0×10^5/ml. While the virus titer did not differ significantly by the time of cell culture for the inoculum cell concentration of 2.0×10^5/ml. Supplementation of 9% fetal bovine serum (FBS) to the cell growth medium was mandatory for clear plaque formation. Among several methyl cellulose (MC) concentrations in the overlay medium, a moderate concentration of 1.25% was optimal to produce clear and distinct plaques on 1 day's culture from 2.0×10^5 cells/ml., 熱帯医学 Tropical medicine 31(4). p151-159, 1989},
 pages = {151--159},
 title = {Optimal Conditions of Plaque Titration of Japanese Encephalitis Virus on BHK21 Cells},
 volume = {31},
 year = {1989}
}