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Updated: Aug 2, 2026

Real Time Measurements of Membrane Protein:Receptor Interactions Using Surface Plasmon Resonance (SPR)
Published on: November 29, 2014
Real-time measurement of spontaneous antigen-antibody dissociation
Simone Kulin1, Rani Kishore, Joseph B Hubbard
1Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
We report observations in real time of thermally driven adhesion and dissociation between a monoclonal IgE antibody and its specific antigen N-epsilon-2,4-dinitrophenyl-L-lysine. Both molecules were attached to the surfaces of different polystyrene microspheres trapped by optical tweezers. Monitoring spontaneous successive attachment and detachment events allowed a direct determination of the reaction-limited detachment rate k(off) for a single bond and also for multiple bonds. We observed both positive and negative cooperativity between multiple bonds depending on whether the antigen was linked to the microsphere with or without a tether, respectively.
We report observations in real time of thermally driven adhesion and dissociation between a monoclonal IgE antibody and its specific antigen N-epsilon-2,4-dinitrophenyl-L-lysine. Both molecules were attached to the surfaces of different polystyrene microspheres trapped by optical tweezers. Monitoring spontaneous successive attachment and detachment events allowed a direct determination of the reaction-limited detachment rate k(off) for a single bond and also for multiple bonds. We observed both positive and negative cooperativity between multiple bonds depending on whether the antigen was linked to the microsphere with or without a tether, respectively.

