Plaque Assay Protocol
The plaque assay is a virological method used to quantify infectious virus particles in a sample. It involves infecting a monolayer of host cells with a diluted virus solution, overlaying with a semi-solid medium to restrict viral spread, and incubating until visible plaques (zones of cell lysis) form. These plaques are counted to determine the virus titer, expressed as plaque-forming units (PFU) per milliliter. This technique is essential for viral research, vaccine development, and studying virus-host interactions.