Steen Laboratory
Equipment
The Proteomics Center at the Children's Hospital is equipped with state of the art instrumentation, which allows our researchers to push the limits with biological mass spectrometry experiments. These resources provide a unique opportunity for developing methods that allow cutting edge research. Mass spectrometry is a rapidly evolving field and as such has important implications in several areas of research, including protein biomarker discovery and validation/screening. The reagent / instrumentation costs and lack of expertise are a significant barrier to the widespread adoption of mass spectrometry in many laboratories. Children's Hospital has invested in equipment that is accessible to all researchers in the community as a pooled resource.
Mass Spectrometers
The LTQ (Thermo Finnigan) is a linear quadrupole ion trap, arguably the fastest and most sensitive instrument on the market for protein identification. The system is equipped with a micro autosampler and fitted for multidimensional microscale capillary liquid chromatography. The high speed and sensitivity is at the expense of resolution and mass accuracy, which are both rather low. Nevertheless, it is the workhorse of the Proteomics Center.
LTQ FT from Thermo Electron is a hybrid instrument. It combines a linear quadrupole ion trap in the front and a Fourier Transform Ion Cyclotron Resonance (FT ICR) mass analyzer at the back end. The FT ICR is euipped with a 7 Tesla superconducting magnet. The instrument is fitted for microscale capillary liquid chromatography (Surveyor HPLC system) and a micro autosampler (Spark Holland). This is an ultra high resolution, ultra high accuracy mass spectrometer which is capable of a resolution 500 000 FWHM at m/z 400. The LTQ FT is also equipped with an electron gun and an IR laser, thus electron capture dissociation and IRMPD (infra-red multiphoton dissociation) can be performed using this instrument. These dissociation methods are ideal for labile modifications.
The LTQ-Orbitrap from Thermo Electron is another hybrid instrument. It combines a linear quadrupole ion trap in the front and a novel resonance mass analyzer at the back end, which has nearly the same mass accuracy as the FT ICR, but better sensitivity. The instrument is fitted for microscale capillary liquid chromatography (Exigent HPLC system) and a micro autosampler (Spark Holland).
QSTAR XL (ESI; ABI/MDS SCIEX) is another hybrid tandem mass spectrometer. It has a quadrupole mass analyzer at the front end and a time-of-flight (TOF) analyzer at the back end. The instrument is fitted with a microscale capillary liquid chromatography system (Agilent 1100) and a micro autosampler (Spark Holland). It is the newest generation of the QSTAR XL and is equipped with a nano DCI source. This source provides more efficient ionization of peptides from solvents with a high aqueous content. The QSTAR is a high resolution, high accuracy instrument that can be used for protein modification analysis.
