Demonstration of yellow fever virus with the electron microscope

Electron microscopic investigations revealed the presence of one type of particle common in yellow fever-infected brain and liver of mice, in KB, HeLa and chick embryo cells, in Aedes aegypti adults, and in concentrated and purified suspensions from KB cells. On this evidence and because of the presence of a limiting membrane around the particles, it is believed that the yellow fever virus agent is a sphere with a dense center, about 38 ± 5 mμ in diameter, and surrounded by a distinct membrane. In the brain, yellow fever virus particles are found exclusively in cisterns and tubuli of the endoplasmic reticulum of astrocytes.