Tandem Mass Tags (TMT®)

In order to allow for differential protein expression analysis of more than two groups (multiplex analysis), we have developed Tandem Mass Tags® (TMT®), simple chemical mass tags which have individual fragmentation patterns in tandem mass spectrometry. Each TMT® in a series comprises a mass reporter group (M) or (M’), a pro-fragmentation linker group (F), a mass normalisation group (N) or (N’) and an amine reactive group.

• M-F-N-(R) First Tag
• M’-F-N’-(R) Second Tag

Unlike other differential tags however, all members of the series have the same overall mass and physical chemical properties ensuring they co-elute during chromatography and mass spectrometry. When the labelled peptides enter the tandem MS ion beam, the TMT®’s pro-fragmentation elements are released giving rise to unique mass to charge signals.

Figure 1 – TMT® differential protein measurement flow diagram. Samples are labelled with different TMT®s and then mixed. After digestion, only TMT® labelled fragments are selected for analysis by LC-MS/MS. The ratio of protein expression between samples is revealed in MS/MS mode by comparing the intensities of the individual reporter group signals.

Using TMT®s it is possible to determine the changes in protein expression levels in response to disease and to study the effects of drug treatments, including dose escalation studies.

To order TMT reagents through Thermo Scientific, click here.