The Reporter Ions Quantifier node determines abundance values and the average Reporter S/N value (for Orbitrap FTMS-acquired data) for the quantification spectra. The quantification spectrum shows the abundances of the different mass or reporter tags detected in the spectrum.
The node also validates the quantification spectra and indicates the results in the Quan Info column and the Quan Info Details column, which denotes whether a quantification spectrum can be used for peptide quantification and protein quantification. The Quan Info Details column, hidden by default, shows why a quantification spectrum is rejected by the method. The following are possible entries for the Quan Info Details column:
- No Quan Values: Indicates that no tag was found.
- Missing Values: Indicates that a tag value is missing, the Reject Quan Results with Missing Channels parameter of the Reporter Ions Quantifier node is set to true, and no imputation is used.
- Rejected By Method: Indicates that the precursor interference is above the user-set threshold or that the average reporter ion signal noise value is too low.
- Filtered by Isolation Interference: Indicates that the spectrum isolation interference is above a user-defined threshold.
- Filtered by Average S/N: Indicates that the average signal-to-noise value is below a user-defined threshold.
- Shared: Indicates that different peptide sequences are associated with a quantification spectrum.