ABSTRACT
Cell monolayers grown in polystyrene culture plates and in glass tubes are routinely used in virology laboratories around the world for virus isolation and identification. Monolayers of different types of cells grown in polystyrene culture plates were found to show a strange cytotoxicity when inoculated with stool samples from healthy children from Bangladesh. When inoculated with 0.2 ml of a 10% stool sample 100% (80/80) of the cell monolayers established in polystyrene plates showed cytopathy by 4 days and 60% (48/80) within first 2 hours of sample inoculation. In contrast only 4% (4/90) of samples inoculated in the same type of cell monolayers but established in glass cell culture tubes showed cytopathy by 4 days; out of these 4 only 2 (2%) showed cytopathy in the first 2 hours. Cytotoxicity could be reduced to half when the amount of inoculated stool sample was reduced by half in cases where polystyrene was used as the substrate. This difference of cytopathy under two different circumstances (polystyrene substrate versus glass substrate) was statistically significant (P less than 0.001).