SURFACE-PLASMON RESONANCE BIOMOLECULAR INTERACTION ANALYSIS MASS-SPECTROMETRY .1. CHIP-BASED ANALYSIS

The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) in concert with surface plasmon resonanc e-based biomolecular interaction analysis (SPR-BIA) is reported. A chi p-based biosensor unit was used to simultaneously monitor biomolecular interactions taking place on four different regions of the sensor chi p (now cells). Species retained during SPR-BIA were then identified by performing MALDI-TOF directly from within the area of the now cells. Analyses were performed on an antibody/antigen/antibody system with de tection limits in the low-femtomole range, The combined assay demonstr ates the use of SPR-BIA to evaluate the relative stability of sequenti al solution-phase interactions, as well as, upon MALDI-TOF analysis, t he ability to unambiguously confirm the presence of species retained d uring the interaction analysis.