Plaque assay for black beetle virus.

A rapidly growing strain of virus was used to develop a reliable plaque assay for Black beetle virus on monolayers of cultured Drosophila cells. Cell density of the monolayer was critical for successful plaque formation. The dose-response curve for plaque formation was linear, supporting earlier proposals that both RNA segments of the split genome reside in the same particle. The method greatly facilitates isolation of reassortant and variant strains of virus.