Virus Plaque Assay

**Semantic type:** Laboratory Procedure

**Definition:** An assay that is used to determine viral quantity by infecting monolayers of host cells with serially diluted virus, covering the monolayers with an immobilizing overlay after a period of incubation to restrict the spread of the virus to neighboring cells, and counting the resulting visible plaques of infected cells.

**Synonyms:** - VIRUS PLAQUE ASSAY