MRM (Multiple Reaction Monitoring) is a targeted mass spectrometry acquisition mode, and the mainstream method in this regard, commonly used for relative or absolute quantification of peptides or other small molecules. With a wide linear dynamic range, and excellent sensitivity, accuracy, and reproducibility, even a high specificity in the presence of chemical standards, MRM is mainly achieved by triple quadrupole mass spectrometry, and PRM is supported by Orbitrap instruments.
Application Scenarios: Absolute quantification of peptides (with external standards or with stable-isotope labeled internal standards)
MRM: Sciex TripleTOF 5600, Sciex 4500 MD
SRM: Thermo Scientific Altis
PRM: Thermo Scientific Q Exactive