Advances in Multiple Reaction Monitoring (MRM) for Targeted Proteomics in Biomedical Research.

Targeted proteomics has emerged as a cornerstone of quantitative biomedical research, enabling precise, reproducible measurement of predefined proteins across complex biological matrices. Among targeted mass spectrometry approaches, multiple reaction monitoring (MRM), typically performed on triple quadrupole (QQQ) instruments, remains the gold standard for sensitive and accurate protein quantitation. Over the past decade, substantial advances in instrumentation, experimental workflows, and computational tools have significantly expanded the analytical depth, throughput, and accessibility of MRM-based assays. Concurrently, innovative strategies for proteome-wide quantitation are addressing longstanding challenges related to standardization, cost, and scalability. This chapter provides a comprehensive overview of the principles underlying MRM, recent technological and methodological advancements, and emerging applications in biomedical research, with an emphasis on biomarker validation, clinical proteomics, and absolute proteome profiling.