From noise to clarity: A stepwise troubleshooting roadmap for elevated negative control signals

EBF YSS 2026 -- Unexpected elevation in the negative control (NC) signal in immunogenicity assays can introduce excessive background noise, reduce assay reliability and trigger a formal investigation. The source of this elevation is not immediately apparent due to the presence of multiple potential contributors, thus reinforcing the need for evidence driven decision‑making rather than assignment of a single failure point.