Biomolecular Interaction Analysis Core

Surface Plasmon Resonance (SPR) is used to monitor macromolecular interactions in real time. The Biacore systems use SPR technology for measuring the interactions of macromolecules with each other, and with small molecules. One of the molecular (ligand)is immobilized on carboxymethylated dextran over a gold surface while the second partner (analyte) flows over the immobilized ligand surface. The immobilized ligands are remarkably resilient and maintain their biological activity.

Interaction is detected via SPR, in real time, at high sensitivity, without the use of radioactivity. The bound analyte can be stripped from the immobilized ligand without affecting its activity to allow many cycles of binding and regeneration on the same immobilized surface. These instruments excel over most other methods of affinity measurements in that they are able to measure on-rates (ka in the range of 103 - 5x107M-1s-1) and off-rates (kd of 10-5 - 1 s-1).