Other reagent and/or lot-specific variables
Antigens may be represented in the single antigen beads assay by differing numbers of unique beads, there are, for example, in a current reagent lot, three A2 beads and five DQ2 beads but only one C7 bead. Subsaturating antibody may be diluted across multiple beads in a multiplexed assay more so than if only a single bead was present, thereby lowering mean fluorescence intensity on any single bead of interest. For higher antibody levels, maximum total bead mean fluorescence intensity may be higher for those antigens with multiple beads. There is no validated methods of combining mean fluorescence intensity across multiple beads, however summing is frequently reported in the literature.