Plaque assay procedure was carried out to determine the infectivity titration of
dengue virus using Aedes albopictus C6/36 mosquito cell line. Cells were seeded in 6 wells
plates and incubated until monolayer C6/36 cell lines were formed. Each well was exposed
to a different dilution of dengue infected culture fluid, followed by addition of first and second
overlay medium. Cells were observed under an inverted microscope and plaque staining was carried out. The results showed that countable plaques were not achieved and plaques formed were restricted to the central section due to the significant partial lysis of the C6/36 cells in the plates. However, the plaque assay technique using C6/36 cell line reported here appears to be promising and merits further detailed studies.