the present invention comprises rugged , inexpensive , reliable , and sensitive laboratory assays of antibody - based viral neutralization activity and antibody - based viral adherence inhibition activity . the assays use inactivated , fluorescently - labeled virus , allowing the tests to be performed without extensive safety precautions . the interaction of the labeled virus with target cells is monitored using flow cytometric methods . a preferred embodiment uses simple and inexpensive flow cytometry methodologies and equipment , such as bead array readers used as simplified flow cytometers . the assays are rapid , taking no longer than a few hours and are readily conducted by a trained technician . the assays are sensitive because they use labeled viruses at low concentrations and determine neutralizing and blocking capacity of sera and antibody at low concentrations . the methods are appropriate for high - throughput screening of large panels of samples .