Ligand binding assays

The methods applied in our lab are used to investigate binding interactions of molecules. Resulting parameters include kinetics, affinity, specificity, concentration and content. We have broad experience in providing tailor-made applications to help understand binding interactions in detail.

We offer setup of methods based on quality by design (QbD) principles. Established protocols are available for a wide selection of protein interactions (such as Fc receptor binding and C1q binding) and may be adapted to your specific needs. Method qualification and validation is performed in accordance with the applicable guidelines, e.g. ICH Q2R1.

Surface Plasmon Resonance (SPR, Biacore T200)

• Biomolecular interaction analysis using a real-time and label-free system

Binding kinetics and affinity

Reportable values:

• Association rate constant k_a (M-1 s-1)
• Dissociation rate constant k_d (s-1)
• Equilibrium constant K_D (M)

Sensorgram comparison

Reportable value:

• Similarity score (%)
• Comparison of samples to „pool” of reference data -> similarity corridor
• Applicable for complex interactions without defined fitting model

Surrogate potency assays

Reportable value:

• % relative potency compared to reference
• Dose-response curve
• Evaluation: PLA, 4PL

Calibration-free concentration analysis (CFCA)

Reportable value: active concentration

• Established assays, e.g.: Fc receptor kinetics and affinity: FcRn, FcγRIa, FcγRIIa, FcγRIIb, FcγRIIIa, FcγRIIIb

ELISA

• different assay formats, such as direct, indirect, sandwich or competitive ELISA can be applied
• Determination of relative potency
• Concentration / content of analyte

Established assays, e.g.: C1q binding (potency), Residual host cell protein (HCP) determination

Glycosylation analysis

• Lectin array technology (GlycoStation)