Plaque Assay

A plaque assay is a laboratory technique used to measure the quantity of infectious viral particles in a sample. It involves adding the virus to a layer of susceptible cells and allowing it to infect these cells. As the virus replicates, it destroys the infected cells, creating clear zones called plaques. By counting these plaques and knowing the dilution level of the original sample, scientists can determine the number of infectious viruses present, expressed as plaque-forming units (PFU) per volume. This method is essential for studying viruses and assessing their infectivity.