SmartBead Technologies has developed a multiplexed immunofluorescence assay, the UltraPlex ANA Profile, which determines nine antinuclear antibodies simultaneously. The UltraPlex assay platform uses bar-coded microparticles to track analytes through assays. These bar-coded microparticles were used to tag and track key ANA markers: Jo-1, Scl-70, Sm, SmRNP, SSA, SSB, U1RNP, Centromere B, dsDNA, and a blank control microparticle. The immunofluorescence assays are fully automated and are performed on a Perkin-Elmer multiprobe II liquid handling system that performs all sera dilutions, additions of reagents, washes, and incubation steps. Results were determined by the automated UltraPlex plate reader. This fully automated multiplex antinuclear antibody (ANA) immunoassay was used to screen commercially available ANA-positive sera and negative control samples. The UltraPlex ANA Profile enables the panels of samples to be screened simultaneously for nine ANA antoantibodies, requiring significantly less labor and fewer reagents, with performance equivalent to existing gold-standard methods.