Characterization of the Breast Cancer Marker Candidate LAG3 Protein in Human Plasma by Direct SPRi-MALDI-MS Analysis from Antibody Arrays

Proteomics plays an important role in biomarker discovery as prerequisite for later utilization. In this study, we coupled Surface Plasmon Resonance imaging (SPRi) with MALDI-TOF mass spectrometry to permit the multiplexed quantification of binding by SPRi and the molecular characterization of interacting partners by subsequent MS analysis. Hyphenation of the two technologies is applied to the detection and characterization of LAG3 (potential breast cancer biomarker) in human serum1.