Cost-Effective and Time-Saving Multiplex-Beads Immunoassay Method to Detect Humoral Immune Responses Against...

The multiplex-bead immunoassay is characterized by its ability to detect multiple analytes simultaneously within a short timeframe and with high precision. Consequently, it is an appealing tool for identifying humoral immune responses to various targets, particularly respiratory viral infections that pose a significant risk to public health. In this study, we optimize the assay by using minimal reagent volumes to reduce both costs and turnaround time without compromising assay accuracy. We have developed a multiplex-bead immunoassay to detect humoral responses against Severe Acute Respiratory Syndrome COVID-19 2 (SARS-CoV-2) and Middle East Respiratory Syndrome COVID-19 (MERS-CoV) on a platform that can be extended to include additional targets. To validate the performance of the developed assay, serum samples from MERS-CoV- and SARS-CoV-2-seropositive and seronegative individuals were evaluated and compared with the standard enzyme-linked immunosorbent assay (ELISA) method. The results demonstrate that the developed multiplex-bead immunoassay exhibits high performance, achieving 100% sensitivity and 95.4%-96.6% specificity, a detection limit comparable to ELISA, and a strong correlation with ELISA (R² = 0.91-0.98) in detecting humoral responses in the tested samples using minimal reagents. Overall, the developed immunoassay offers a rapid method for simultaneously detecting humoral responses for multiple analytes, with high sensitivity and specificity and lower costs than ELISA.