Techniques which serve to quantify protein content by means of mass spectrometry. The principle lies in the introduction of a mass tag to an internal standard protein/peptide containing different stable isotopes than the protein/peptide in the sample. Mass resolved signals originating in the internal standard and the sample are read individually and evaluated.
Note: In the case of a complex sample, the use of multiple reaction monitoring allows for the resolution of multiple overlapping signals.
Source:
PAC, 2018, 90, 1121. 'Terminology of bioanalytical methods (IUPAC Recommendations 2018)' on page 1164 (https://doi.org/10.1515/pac-2016-1120)