The use of serological assays to monitor the health status of swine herds has been used for several decades. The primary assays employed have included agglutination, neutralization, and/or ELISA assays to detect the presence of serum antibodies to a specific infectious agent. The current work indicates that a flow cytometric assay can be used to evaluate serum samples for antibodies reactive with multiple antigen in a single reaction tube. The ability to detect antibody responses to five separate Salmonella endotoxin preparations in a single tube was shown. There are several advantages of this type of assay over traditional plate ELISA assays. For example, different set of beads coated with a variety of antigens can be mixed in a single reaction tube. The beads could be coated with bacterial, viral, parasitic, or fungal antigens and combined in a single reaction tube. In addition, the amount of serum sample required for the assay is small (less than 100 µL) regardless of the number of antigen-coated bead sets used in the assay. Lastly, the use of this technology should be useful diagnostically as well as in monitoring the health status of livestock animals.