Surface Plasmon Resonance (SPR) is an optical technique to monitor label-free molecular interactions in real time. It provides information on kinetic processes (association and dissociation), binding affinity and molecule detection. SPR imaging (SPRi) uses SPR in a micro-array approach. It is the ideal solution for rapid and multiplexed investigations. It allows: • the rapid quantification and monitoring of biomolecular interactions • the study of up to several hundreds of label-free bindings simultaneously In a single experiment, different parameters can be studied and compared: association rate, dissociation rate, affinity constant…. Applications range from the monitoring of DNA:DNA, protein:DNA, protein:ligand or peptide:ligand interactions in the fields of drug discovery process, early diagnosis, biosecurity, therapeutic antibodies, etc.