Mass
spectrometry is a powerful analytical technique that is used to identify
unknown compounds, to quantify known compounds, and to elucidate the
structure and chemical properties of molecules. Detection of compounds
can be accomplished with very minute quantities. Mass spectrometry
provides valuable information for protein identification, thus it is
essential to the study of proteomes.
A mass spectrometer is an
instrument that can separate charged atoms or molecules according to
their mass-to-charge ratio. Relative molecular masses of organic compounds
and biopolymers can be measured in this way. The sample is introduced
into the mass spectrometer, which is generally kept under high vacuum.
Compounds are converted into gas phase molecules either before or during
the ionization process, which takes place in the ion source. The produced
ions are repelled out of the ion source and accelerated towards the
analyzer region. Although both positive and negative ions may be
generated at the same time, one polarity is chosen and either positive or
negative ions are analyzed and recorded. Molecules that do not ionize,
i.e. remain neutral, are pumped away and will not be detected.
The Mass
Spectrometry laboratory at the Maiman
Institute for Proteome Research is equipped with a state-of-the
art Voyager DE-STR MALDI-TOF
and a Q-STAR
Pulsar LC/MS/MS mass spectrometers. The
facility is currently offering services to analyze intact proteins,
peptides and other bio-molecules.
Methods for preparation of peptides from proteins separated by 1D
and 2D gels have been evaluated and we are pleased to offer protocols and
advice on sample preparation to potential users.
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