Immunoassay

Immunoassay refers to analytical techniques using antibody-antigen interactions to detect and quantify biological molecules such as proteins, hormones, cytokines, or therapeutic drugs in complex samples. These assays provide high sensitivity and specificity, with common formats including enzyme-linked immunosorbent assays, chemiluminescent assays, lateral flow tests, and multiplex bead-based platforms. Immunoassays support clinical diagnostics, biomarker measurement, and biopharmaceutical product characterisation.

The biopharmaceutical industry employs immunoassays throughout discovery, development, and manufacturing to measure therapeutic concentrations, monitor immune responses, and support quality testing. Pharmacokinetic studies rely on immunoassays quantifying biologic drug levels in patient samples. Immunogenicity assessment uses immunoassays detecting anti-drug antibodies and neutralising antibodies. Biomarker programmes measure cytokines, soluble receptors, or pathway markers supporting mechanism of action validation. Manufacturing and quality control applications include potency assays, impurity detection, and lot release testing. Assay development requires optimisation for specificity, sensitivity, dynamic range, and matrix effects, while validation ensures accuracy, precision, and robustness.