A novel multiplex serological immunoassay for health monitoring in rodents.

Health monitoring of laboratory rodents is essential for ensuring animal welfare, meeting regulatory requirements for zoonosis control, and maintaining the integrity and reproducibility of scientific studies. Routine serological screening, conducted in accordance with FELASA guidelines, plays a critical role in the detection of infectious agents. While conventional serological assays typically target individual pathogens, bead-based multiplex platforms require costly instrumentation and an additional bead functionalization step, which limits their routine implementation in animal facilities. In this study, we evaluated the performance and usability of a multiplex ELISA-like assay (MIRIAD®, GD Biotech, France), designed for in-house serological surveillance of laboratory rodents. A total of 68 mouse and 27 rat serum samples were screened using the recommended quarterly serological monitoring panel. A subset of 22 mouse and 5 rat serum samples was further evaluated using the recommended annual monitoring panel. The results were compared with two commercially available single-target ELISAs, one for mice (Charles River, Wilmington, MA, USA) and one for rats (Biotech Trading Partners, Encinitas, CA, USA). Concordance rates ranging from 94% to 100% were observed across all 26 target pathogens tested. Compatibility with dried blood spot (DBS) cards was also evaluated, demonstrating reliable antibody detection after storage and elution, and supporting the potential for reduced sample volumes and simplified sample handling. These findings highlight the multiplex ELISA-like assay potential as a practical and efficient tool for routine serological health monitoring in laboratory animal facilities. Its ease of use, minimal sample requirements, and compatibility with DBS technology can facilitate more frequent testing, support early detection of pathogens, and promote adherence to the 3Rs (Replacement, Reduction, and Refinement) principles through refinement of health-monitoring practices.