Mass-Linked Immuno-Selective Assays in Targeted Proteomics

摘要

The issue of how to rapidly identify and quantify multiple proteins of known structure in biological samples is a subject of great interest today, particularly in the biomarker validation and clinical proteomics arenas. The potential of mass spectrometry (MS) in this endeavor is an important issue. Will MS-based methods be superior to current protein-assay technology for routine monitoring? Does MS have sufficient sensitivity and accuracy for clinical use? Can it compete with conventional assays in cost, speed, ease of use, and reliability? In short, what role will MS play in the future of routine protein assays? The ease and speed with which peptides can be resolved, fragmented, sequenced, identified, and quantified in the gas phase is an extremely valuable asset of MS, as we have learned from proteomics. But as a prelude, proteins in samples must undergo purification and enrichment along with reduction, alkylation, and proteolysis in many cases before they are ready for MS analysis. Whereas MS analysis occurs in milliseconds or less, much of the preliminary sample preparation is achieved in lengthy manual or robotic steps with substantial variability and expenditure of time. Although tolerable in discovery, extensive sample manipulation, deficiencies in selectivity, and poor reproducibility compromise MS detection strategies in routine analysis.