Hi everyone, I have two questions about the iTRAQ quantitation by libra. (1) Why are the iTRAQ label intensities of peptides in the Libra output files different from the intensities in the native ms/ms spectrum? (2) Suppose a single precursor ion triggers two MS/MS scans (two HCD- CID pair). However only one out of the two HCD-CID scans enabled the peptide and corresponding protein identification, then does Libra uses that particular scan (HCD) for iTRAQ quantitation? Since the Libra output file does not give any information about retention time or scan # for the individual quantified peptides, it is extremely difficult to know which HCD scan (out of many for a precursor ion of a peptide) was used to do the measurement.
Any thoughts folks have on this is appreciated. Thanks! -Rich -- You received this message because you are subscribed to the Google Groups "spctools-discuss" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/spctools-discuss?hl=en.
