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P2013
Label-Free Optical Biosensor for Probing Receptor Biology  Theory, Modeling & Applications
Presenter Ye Fang, Corning Incorporated, USA
Additional Authors: Ann M. Ferrie, Elizabeth Tran, Gary Li, Florence Verrier, Jun Xi, and Meenal Soni
Label-free optical biosensors have migrated from a tool solely for biomolecular interaction analysis to a universal platform for both biochemical and cell-based assays. This poster presents the theoretical analysis and experimental data for the use of resonant waveguide grating (RWG) biosensors to characterize stimulus-mediated cell responses, including receptor signaling. The biosensor is capable of detecting redistribution of cellular contents in directions that are perpendicular and parallel to the sensor surface. This capability relies on online monitoring of cell responses with multiple optical output parameters, including the changes in incident angle wavelength and the shape of the resonant peaks. When the changes in the peak shape contributed to stimulation-modulated inhomogeneous redistribution of cellular contents parallel to the sensor surface, the shift in the incident angle wavelength primarily reflects the stimulation-triggered dynamic mass redistribution (DMR) perpendicular to the sensor surface. The optical signatures are obtained and used to characterize several cellular processes, particularly receptor signaling. A mathematical model is developed to link the bradykinin-mediated DMR signals to the dynamic relocation of intracellular proteins and the receptor internalization during B2 receptor signaling cycle. Chemical biology and cell biology analysis provides evidence linking specific cellular events to a ligand-induced DMR signal. Together with recent advances in instruments for high-throughput screening, the newly discovered ability of optical biosensors for assaying living cells will accelerate a wide adoption of label-free biosensors in both drug discovery processes and fundamental research.