Complement-dependent cytotoxicity is an important effector mechanism of immunoglobulin G antibodies, initiated when the antibody fragment crystallizable (Fc) region binds complement protein complement component 1q (C1q). Because this interaction is closely associated with cytotoxic activity, C1q binding is an important parameter in therapeutic antibody development and quality assessment. Reliable characterization requires analytical methods that can measure molecular interactions and demonstrate consistent assay performance.
This application note describes a biolayer interferometry-based C1q binding assay and its qualification for therapeutic antibody characterization, covering key assay design considerations and the evaluation of specificity, precision, accuracy, linearity, and robustness.
Download this application note to learn:
- How biolayer interferometry characterizes antibody–C1q binding interactions and kinetics
- Which assay design choices help preserve Fc accessibility and minimize avidity effects
- How specificity, precision, accuracy, linearity, and robustness are evaluated during assay qualification
