For label-free interaction measurements, Bio.services provides surface plasmon resonance (SPR) service based on our unique ProteOn XPR36 protein interaction array system. Bio.services has extensive experience in providing SPR services. You can count on us to assist you through your project.

SPR is an optical phenomenon which allows monitoring binding of any two unlabeled molecules in real time. The SPR signal is based on changes in the refractive index at the surface of a gold sensor chip as an analyte flows in a microfluidic channel and binds to a ligand immobilized on the sensor chip. Monitoring the changes in the SPR signal over time results in a plot of the binding response versus time called sensogram. Fitting of the sensogram data allows calculation of binding parameters, such as KD, Kon and Koff. On top of the kinetic constants, SPR measurements can be applied for:

  • Determination of specificity
  • Studying thermodynamics of interaction
  • Investigating mechanism of action
  • Epitope characterization or affinity screening