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Updated: Jun 25, 2026

Selected Reaction Monitoring Mass Spectrometry for Absolute Protein Quantification
Published on: August 17, 2015
How specific is my SRM?: The issue of precursor and product ion redundancy
Jamie Sherman1, Matthew J McKay, Keith Ashman
1Department of Chemistry and Biomolecular Sciences, Australian Proteome Analysis Facility, Macquarie University, Sydney, Australia.
Abstract:
Selected reaction monitoring (SRM) MS is proving to be a popular approach for targeted quantitative proteomics. The use of proteotypic peptides as candidates for SRM analysis is a wise first step in SRM method design. The obvious reason for this is the need to avoid redundancy at the sequence level, however this is incidental. The true reason is that homologous peptides result in redundancy in the mass-to-charge domain. This may seem like a trivial subtlety, however, we believe this is an issue of far greater significance than the proteomic community is aware. This VIEWPOINT article serves to highlight the complexity associated with designing SRM assays in light of potential ion redundancy.
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