When are antibody competition experiments informative?

Why

In sequential binding experiments, saturate antigen with one antibody and measure whether the second can still bind. Reciprocal ordering helps reveal asymmetric behavior from affinity, kinetics or steric obstruction. A lack of second binding may reflect true epitope overlap, spatial crowding, conformational effects or antigen displacement.

Therefore, binning provides an operational grouping rather than a residue-level map. Monitor antigen integrity and aggregation, avoid sensor overloading and repeat with different immobilization orientations when the antigen is multivalent. For a candidate antibody pair, non-competition is encouraging for sandwich assays or bispecific targeting but does not guarantee simultaneous binding on native cell surfaces.

Validate promising pairs with structural, mutational or cell assays as appropriate.