Next-generation Etd Module

At Pittcon 2008, Bruker Daltonics announced ETD II, a next-generation ETD (electron transfer dissociation) module for its HCT-Ultraâ„¢ high capacity ion traps. ETD is a very powerful peptide and protein fragmentation technique that preserves functionally important post-translational modifications (PTMs), such as phosphorylations or glycosylations. With ETD in a spherical high-capacity ion trap, the sequencing and identification of proteins, as well as the identification and localization of PTMs are facilitated with greatly improved scores and confidence.

In 2005, Bruker Daltonics introduced the first commercial ion trap equipped with ETD, which quickly became the market leader for ETD-ITMS due to the unique advantages of its spherical geometry, which easily traps positive analyte ions and negative ions in the same small spherical volume for maximum ETD interaction efficiency. This spherical trap geometry yields far improved ETD sensitivity, with a factor of 10-100x better sensitivity than ETD in linear ion traps. ETD also overcomes the low-mass cut-off in ion traps. Due to its superior ion trap mass accuracy, the HCT-Ultra with ETD enables powerful de novo sequencing capabilities, even for difficult to dissociate proteins.
In 2007, the related PTR (Proton Transfer Reaction) technology was first introduced commercially by Bruker. Due to the HCT-Ultra’s inherent greater m/z range of 3,000, and its better mass resolution that can resolve 3+ and 4+ charge states of peptides on-the-fly at full analytical speed, ETD/PTR on the HCT-Ultra can be used for proteins up to and above 12 kDalton, providing an estimated factor of 3x higher effective protein mass range than on linear ion traps.

Bruker enhances this key proteomics technology even further with the introduction of the improved ETD II accessory. ETD II is based on a novel and compact nCI (negative chemical ionization) source with increased ETD/PTR reactant ion generation, resulting in rapid, sub-fmol sensitivity for the confident characterization of PTMs. In combination with the ETD efficiency and sensitivity advantages of the spherical high capacity trap, ETD II is designed to provide the most sensitive, fastest and robust ETD fragmentation, plus the PTR effective mass range extension for intact protein characterization and top-down PTM characterization.