High-throughput optimization and transfer of binding kinetics assays from BioLayer Interferometry platforms to Surface Plasmon Resonance

Biologics are pharmaceutical drug products whose active drug substance is produced in a living organism by means of recombinant DNA technology. Therapeutic antibodies, which covers roughly a third of the approved biologics, require a full characterization in order to get approval. Biosensors are used in many stages of the drug development process for the characterization of the drug-target interaction, including the binding kinetics of the interaction. To achieve reliable kinetic measurements of the binding interaction, the binding kinetics assay must be thoroughly optimized. The optimization may take weeks using the sensitive Biacore T200 surface plasmon resonance (SPR) –instrument, but the use of a more high-throughput biosensor instrument could speed up the optimization process. The aim of this study was to investigate if and to what extent can the binding kinetics assay conditions be transferred between the Biacore T200 SPR instrument and a more high-throughput FortéBio’s Octet RED96e BioLayer Interferometry (BLI) biosensor instrument. The transferability was investigated by optimizing the individual assay steps first on the BLI platform and subsequently transferring the assay conditions to the SPR instrument using several model proteins. The results from the model proteins suggest that the regeneration conditions are transferred well between the platforms. The regeneration is used between subsequent binding cycles to force the analyte to dissociate from the biosensor enabling multiple measurements using one sensor. The effect of the ionic strength of the running buffer on the non-specific binding was similar on both instruments but the addition of certain additives had the opposite effect on the non-specific binding between the instruments. Thus, the use of BLI platform can speed up the optimization process of binding kinetics assays, but the final optimization of the running buffer must still be performed on the SPR instrument, where the final kinetic measurements are performed