Real-time binding data with Biacore™ SPR: from principles to application

Biacore™ can analyze a broad range of molecules, including antibodies, proteins, peptides, nucleic acids, small molecules, ADCs, and even complex membrane proteins. The technology works equally well with purified samples, supernatants, or serum, thanks to its high sensitivity and low sample consumption. This versatility makes Biacore™ suitable for applications ranging from early discovery screenings to regulated drug development studies.

Yes. Biacore™ SPR is widely used to study antigen-antibody interactions during vaccine development. It allows mapping of epitopes, evaluating binding strength, and screening antibody or peptide libraries to identify promising vaccine candidates. By monitoring kinetics in real time, Biacore™ helps validate formulations, optimize dosing strategies, and generate data that can support regulatory submissions in both preclinical and clinical phases.

A sensorgram is the graphical output of a Biacore™ assay, showing the interaction between a ligand immobilized on the sensor chip and its analyte. The rising curve represents the association phase, where molecules bind, and the declining curve corresponds to dissociation, when binding is reversed. From these curves, association rate (ka) and dissociation rate (kd) constants are calculated and the subsequent equilibrium dissociation constant - Affinity- (KD) is determined. Proper interpretation of sensorgrams is key to differentiating between strong, stable binders and weak, transient interactions.

FcRn binding measures the interaction of antibodies with the neonatal Fc receptor at pH 6.0 and pH 7.4. These assays investigate the pH-dependent nature of the interaction which gives an indication of how efficiently antibodies are recycled instead of degraded, and to predict initial data about the half-life of the Drug i. Understanding FcRn binding is critical in therapeutic antibody development, as it guides strategies to extend circulation time and improve dosing regimens. Biacore™ SPR provides a robust, label-free way to study these interactions under physiologically relevant conditions.

CFCA (Calibration-Free Concentration Analysis) is a Biacore™ method for determining the active concentration of molecules without requiring a standard curve. Unlike ELISA or traditional assays, CFCA directly measures functional binding, ensuring that only biologically active molecules are quantified. It requires very little sample, delivers fast results, and is highly reproducible. This makes CFCA particularly valuable for batch-to-batch comparability, QC testing, and stability studies under stress conditions.

Yes. SPR enables real-time, label-free detection of anti-drug antibodies (ADA) and neutralizing antibodies (NAbs). Unlike ELISA, which can miss low-affinity or IgG4 responses, Biacore™ captures all binding events as they occur, even transient ones. This increases sensitivity and reduces false negatives. As a result, SPR is increasingly used in immunogenicity testing to ensure drug safety and efficacy during preclinical and clinical phases.

Reproducibility depends on careful assay design, proper use of reference surfaces, and optimal conditioning of the Biacore™ sensor chip. Rigorous quality controls such as monitoring baseline drift, controlling regeneration cycles, and standardizing buffers also play a major role. Working with an experienced CRO like Agro-Bio ensures that all these factors are managed systematically, leading to reliable and auditable results that meet regulatory expectations.