Hello Islam

In my best known it will be difficult to find the exact balancer group identity due to manufacturer patent, they are some images of the generic structure for this tags an also for the 4-plex.

some references are:

https://www.researchgate.net/publication/283567390_Dissecting_the_iTRAQ_data_analysis

https://www.researchgate.net/publication/275947010_Stable_isotope_labelling_methods_in_mass_spectrometry-based_quantitative_proteomics

Chapter Dissecting the iTRAQ data analysis

Article Stable isotope labelling methods in mass spectrometry-based ...

Hello Oscar,

Thanks for your consideration.

SCIEX are still somewhat secretive with regard to the 8plex structure? Have you asked them directly ([email protected])?