Assay, Viral Plaque
Method for measuring viral infectivity and multiplication in Cultured Cells. Clear lysed areas or plaques develop as the Viral Particles are released from the infected Cells during incubation. With some Viruses, the Cells are killed by a cytopathic effect; with others, the infected Cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque Cells contain Viral Antigens which can be measured by IMMUNOFLUORESCENCE.