Currently available Surface plasmon Resonance (SPR) systems allow kinetic measurements in a small number of spots (usually 4) on one sensor-chip. The increasing need to elucidate and follow protein-protein interactions in Proteomics and Biomolecular Engineering requires development of systems with higher throughput in order to accelerate research processes. We present the ProteOn XPR36, a new instrument with parallel sample processing to meet the challenge of higher throughput while maintaining all the unique qualities of SPR optical biosensors. The ProteOn uses a novel microfluidics system to achieve simultaneous measurements in an array of 36 active spots and 42 reference spots. All stages of the biological experiment, from surface immobilization of "ligand" proteins to their subsequent reaction with "analyte" proteins are measured in real time to provide comprehensive data on 36 interactions. In this paper, we demonstrate the efficient application of ProteOn to the selection, ranking and epitope mapping of 20 monoclonal antibody supernatants. The aim of this project was to rank these antibodies on the basis of kinetic binding constants. In addition, epitope-mapping characterization was performed in order to identify antibodies with different epitopes on the IL-9 antigen. The results show that screening and ranking of these 20 hybridoma supernatants were successfully achieved with speed and precision using the ProteOn System. Five high affinity antibodies were identified. One antibody exhibited a significantly higher affinity due to a slower off-rate reinforcing the importance of screening antibodies on the basis of kinetic constants. Epitope mapping of the five top supernatants showed that two supernatants recognize different epitopes on the IL-9 antigen. Both epitope mapping and hybridoma ranking were accomplished with efficiency and accuracy using the parallel processing capability of the ProteOn system.

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