In Vitro Cell Culture Infectivity Assay for Human Noroviruses
Figure 1. Light and transmission electron micrographs of uninfected and infected tissue aggregates with a combined stock of noroviruses representing 3 strains (Passage 0 [P0]). A) Uninfected tissue aggregates displaying well-formed microvilli. B) Infected tissue aggregates exhibiting vacuolization and shortening of the microvilli. C) Transmission electron microscopy (TEM) at 1 h postinfection showing possible norovirus in a microvillus. D) TEM at 24 h postinfection showing significant vacuolization, and internal membrane rearrangement. E) TEM at 66 h postinfection showing accumulation of suspect norovirus particles.