Assay Interference

Assay Interference describes conditions where sample components, drug molecules, anti-drug antibodies, or matrix factors produce false or biased analytical results by affecting signal generation, reagent function, or calibration accuracy rather than reflecting true analyte concentrations. Identifying and managing interference sources ensures data reliability.

The biopharmaceutical industry addresses assay interference throughout bioanalytical method development and validation. Haemolysis, lipaemia, and bilirubin in biological samples may affect optical detection. Anti-drug antibodies in immunogenicity samples create interference requiring confirmatory assays. Target antigen saturation affects free drug measurement. Concomitant medications may cross-react with antibody reagents. Validation experiments specifically challenge methods with potential interferents demonstrating acceptable performance under realistic conditions. Regulatory guidelines require systematic interference investigation. As drug modalities become more complex and combination therapies increase, managing assay interference remains essential for generating reliable data supporting sound clinical and regulatory decisions.