Testing is performed on the BioPlex 2200 System. For the detection of viral capsid antigen (VCA)-IgG antibody, EA-D antibody, and Epstein-Barr nuclear antigen (EBNA) antibody, an aliquot of the patient serum, sample diluent, and bead reagent are combined in a reaction vessel. After washing, antihuman-IgG antibody conjugated to phycoerythrin (PE) is added to the beads and incubated. Another wash step removes excess conjugate, and beads are subsequently resuspended in wash buffer. The bead mixture passes through a detector where the identity of each bead is determined by the bead's dye fluorescence. In addition, the amount of antibody captured by the antigen is measured by the fluorescence of the bound PE.
For the detection of VCA-IgM antibody, the patient sample is combined with diluent containing antihuman IgG and bead reagent. The antihuman IgG is incorporated in the mix because any anti-VCA-specific IgG present may compete with the IgM for binding sites, leading to false-negative VCA-IgM results. After a wash cycle, antihuman-IgM antibody conjugated to PE is added. Detection of anti-VCA-specific IgM is performed as described above for the VCA IgG assay.(Package inserts: BioPlex 2200 System EBV IgG and EBV IgM, Bio-Rad Laboratories Clinical Diagnostics Group, Hercules CA, 2012)