Antibody-based enrichment of peptides on magnetic beads for mass-spectrometry-based quantification of serum biomarkers

摘要: A major bottleneck for validation of new clinical diagnostics is the development highly sensitive and specific assays quantifying proteins. We previously described a method, stable isotope standards with capture by antipeptide antibodies, wherein tryptic peptide selected as stoichiometric representative protein from which it cleaved, enriched biological samples using immobilized quantitated mass spectrometry against spiked internal standard to yield measure concentration. In this study, we optimized magnetic-bead-based platform amenable high-throughput demonstrated that antibody followed can achieve ion signal enhancements on order 103, precision (CVs <10%) accuracy (relative error ∼20%) sufficient biomarkers in physiologically relevant ng/mL range. These methods are generally applicable any or fluid interest hold great potential providing desperately needed bridging technology between biomarker discovery application.