LLCMK2 cells infected with Japanese encephalitis virus were studied by transmission electron microscopy, with a special consideration on the nature of white round granules of 0.4-1.3 μm dIameter with a scanning electron microscope. Virus particles were detected in cytoplasmic vacuoles with smooth-surfaced membranes, in those with rough-surfaced membranes and also in the perinuclear space. Besides the virus-enclosing vacuolar structures many lipid droplets were observed in the cytoplasm of infected cells, although they were few in control non-infected cells. These droplets were supposed to correspond to the white granules observed by a scanning electron microscope
