Development of Plaque Assay Systems for Poliovirus.

To properly evaluate the efficiency of the LVAS Large Volume Air Samples for virus collection, the development of a simple, reliable and efficient virus assay technique is required. To date, the plaque assay offers the most economical and reliable method for quantitation of infectious virus. The usefulness of a plaque assay for quantitation of airborne viruses is dependent upon the suitability of a particular host biological system for isolation of a specific virus. Since host cells vary in their susceptibility to viruses, optimal conditions for host-cell-virus interaction must be ascertained for each type of virus to be collected and assayed. The vaccine strain of poliovirus type 1 Sabin was chosen as a suitable test virus for initial evaluation of the efficiency and sensitivity of the LVAS for collection of viruses. This virus was chosen because it grows well in cell culture, its quantitation by plaque assay has been previously documented and it is a relatively safe virus with which to work. This report describes and compares two plaque assay techniques.