What controls help distinguish specificity from nonspecific sticking?

Why

A rigorous screen combines a concentration series on intended antigen with binding against unrelated proteins, blank sensor surfaces and a suitable polyspecificity panel. Where cells are used, compare parental or knockout controls, gate viable cells, control secondary reagents and block Fc receptors when relevant. Measure aggregation and sample quality because large immunoglobulin aggregates can create high background and misleading avidity.

Evaluate whether a signal scales with antigen expression and is reduced by a specific competitor, while recognizing that nonspecific charge interactions may also depend on sample preparation. An antibody can bind its target strongly while also displaying clinically important polyreactivity. Do not rely on one nonspecific-binding assay to claim the entire cross-reactivity risk is absent.

Document the tested panel and assay sensitivity.