Method Description

Detection of IgG-class antibodies to Toxoplasma gondii, rubella, cytomegalovirus, and herpes simplex virus types 1 and 2 is performed on the BioPlex 2200 system, which uses multiplex flow immunoassay technology. Five different populations of fluorescently-dyed beads are each coated with antigens unique to each infectious organism. Patient sample is combined with sample diluent and the 5-bead set and then incubated at 37° C. During this time, IgG antibodies will bind to the antigen-coated beads. After a wash cycle, a fluorescently-labeled antihuman IgG antibody conjugate is added to the mixture and incubated at 37° C. Following a wash step to remove unbound conjugate, the bead mixture is passed through a detector that identifies the bead based on dye fluorescence and determines the amount of antibody captured by the antigen based on fluorescence of the antihuman IgG conjugate. Raw data are calculated in relative fluorescence intensity and is converted to an antibody index for interpretation.

Three additional dyed beads, an internal standard bead, a serum verification bead, and a reagent black bead are present in each reaction mixture to verify detector response, the addition of serum to the reaction vessel, and the absence of significant nonspecific binding in serum, respectively.(Package inserts: BioPlex 2200 System, ToRC IgG. Bio-Rad Laboratories; 03/2012; BioPlex 2200 System, MMRV IgG. Bio-Rad Laboratories; 02/2019; BioPlex 2200 System, HSV1 and 2 IgG. Bio-Rad Laboratories; 04/2019)