Fig. 2: Typical plate layout of the PRNT.

a, Due to the plaque assay element of the assay, each 96-well neutralization plate requires four 24-well cell plates. b, The first 24-well cell plate contains the VOC and reference wells. c, The remaining three 24-well cell plates contain samples 1 to 6. VOC contains no serum and is used to determine the foci count (100% unneutralized) for the analysis. NVC contains no serum or virus and is used to ensure that cell monolayers are of good quality and that no virus cross-contamination has occurred during assay setup.