Antibody interaction analysis

Understand antibody kinetics and selectivity

Benefits

SPR biosensor-based technology has several advantages over conventional methods for antibody characterization (such as enzyme immunoassays and radioimmunoassay): No labelling is required, sample consumption is low, the method is fast and the output is information rich. Flexible experimental design can provide information about such diverse parameters as interaction model, affinity, rate constants, temperature- and pH dependency as well as epitope specificity.

Deliverables

  • KD values
  • Kinetic constants (kon, koff)
  • Mechanistic model
  • Epitope reactivity matrix showing the binding ability of pairs of Abs to an antigen.
  • Temperature and pH dependency of the interactions

Technical details

In epitope mapping, epitope specificity is determined by testing the ability of pairs of monoclonal antibodies (mAbs) to bind simultaneously to an antigen. Typically, a first mAb is immobilized onto the chip surface and then utilized to capture an antigen of interest. A second mAb is subsequently flowed over the antigen surface. If the second mAb is directed towards an epitope distinct from that of the first mAb (non-competitive), it will bind, whereas if it is directed towards an epitope closely related to the epitope of the first mAb it will interfere with binding (competitive).

Epitope mapping

A) Immobilized mAbs on a chip surface with captured antigen and two types of ”secondary” mAbs. Green mAbs are non-competitive binders whereas red mAbs are competitive.

B) A reactivity matrix showing the binding ability of pairs of mAbs to an antigen along with epitope pattern definitions.

C) A diagram representing the relationship between epitopes. Overlapping epitopes are competitive, non-overlapping epitopes are non-competitive.