QuantStudio™ 12K flex OpenArray™ chip as a tool for high-throughput immunogene expression analysis in chinook salmon Oncorhynchus tshawytscha

• A custom OpenArray™ Chip was compared to conventional PCR for assessing gene expression • Chinook Salmon were infected with Vibrio anguillarum for this assessment • Upregulation of key pro-inflammatory cytokines il-1β and il-8 was observed and correlated well between methods • The species-specific design of the chip provides a valuable tool for rapid assessment of gene expression Salmon aquaculture is the fastest growing food production system globally, increasing the need for efficient disease management strategies. In this study, a high-throughput OpenArray™ TaqMan® RT-qPCR platform for quantifying inflammatory gene expression in Oncorhynchus tshawytscha (Chinook salmon) following Vibrio anguillarum infection was validated. This platform enables the simultaneous quantification of 28 gene transcripts across 48 samples, improving throughput for immunological monitoring. Expression patterns in lymphoid tissues (head kidney and spleen) over a 96-hour infection period revealed significant upregulation of key pro-inflammatory cytokines ( il-1β and il-8 ), which was confirmed by SYBR RT-qPCR, with moderate to strong correlation between methods. These findings highlight the systemic inflammation in response to bacterial challenge and demonstrated the utility of the OpenArray™ platform for rapid immune profiling in salmonids. The species-specific design of the chip provides a valuable tool for comparative immunology and health monitoring across Salmoniformes, supporting the development of tailored health management approaches in salmon aquaculture.