Luminescent signal magnitude corresponds with infectious units. Cells were infected with 10-1/3 serial dilutions of rotavirus for 18 hours. Plates were fixed and probed with anti-VP6 mAb A6M followed by peroxidase-conjugated goat anti-mouse IgG. Signals were developed with chemiluminescent substrate and measured on a ThermoElectron Fluroskan and scored as relative light units (rlu). Error bars are standard errors of the means (n = 5).