Advancing the sensitivity of selected reaction monitoring-based targeted quantitative proteomics


  • Tujin Shi,

  • Dian Su,

  • Tao Liu,

  • Keqi Tang,

  • David G. Camp II,

  • Wei-Jun Qian,

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  • Richard D. Smith

    Corresponding author
    1. Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
    • Correspondence: Dr. Richard D. Smith, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA

      E-mail: Fax: +1-509-371-6564

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Selected reaction monitoring (SRM) – also known as multiple reaction monitoring (MRM) – has emerged as a promising high-throughput targeted protein quantification technology for candidate biomarker verification and systems biology applications. A major bottleneck for current SRM technology, however, is insufficient sensitivity for, e.g. detecting low-abundance biomarkers likely present at the low ng/mL to pg/mL range in human blood plasma or serum, or extremely low-abundance signaling proteins in cells or tissues. Herein, we review recent advances in methods and technologies, including front-end immunoaffinity depletion, fractionation, selective enrichment of target proteins/peptides including posttranslational modifications, as well as advances in MS instrumentation which have significantly enhanced the overall sensitivity of SRM assays and enabled the detection of low-abundance proteins at low- to sub-ng/mL level in human blood plasma or serum. General perspectives on the potential of achieving sufficient sensitivity for detection of pg/mL level proteins in plasma are also discussed.