Targeted mass spectrometry

Targeted mass spectrometry is a mass spectrometry technique that uses multiple stages of tandem mass spectrometry (MSn with n=2 or 3) for ions of specific mass (m/z), at specific time.[1] The values of the m/z and time are defined in an inclusion list which is derived from a previous analysis.

Applications

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Targeted analysis allows the thorough analysis of all ions, at all abundance range above the noise level, at any time window in the experiment. In contrast, non-targeted analysis would, typically, only allow detection of the most abundant 50-100 ions over the entire experiment time. Such limitation of non-targeted analysis makes it less suitable for analyzing highly complex, highly dynamic sample such as human blood serum.[2]

However, the methods of utilizing targeted mass spectrometry are still at a primitive stage, in the sense that the inclusion list used in the targeted analysis is typically manually typed-in by scientists. In addition to that, only one inclusion list is allowed for the entire experiment. Such manual process is both labor-intensive and error-prone. This is largely due to the lack of software to control the mass spectrometer.

Automation

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There have been some efforts in automating the generation of inclusion lists through the solution of external software. In 2010, Wu et al.[3] introduced a semi-automatic method in an effort of identifying low-abundance glyco-peptide. They implemented the automation through iterative experiments and the open-source software GLYPID.[4] With minor modification, this approach can be used in analyzing any other simple or complex samples. In addition to the advantage mentioned before, this semi-automated approach also saves substantial amount of time and efforts for scientists in manually picking ions and re-calibrating instruments.

See also

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References

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  1. ^ Chicooree, Navin; Unwin, Richard D.; Griffiths, John R. (2015). "The application of targeted mass spectrometry-based strategies to the detection and localization of post-translational modifications". Mass Spectrometry Reviews. 34 (6): 595–626. Bibcode:2015MSRv...34..595C. doi:10.1002/mas.21421. ISSN 0277-7037. PMID 24737647.
  2. ^ Gillette, Michael A (2013). "Quantitative analysis of peptides and proteins in biomedicine by targeted mass spectrometry". Nat Methods. 10 (1): 28–34. doi:10.1038/nmeth.2309. PMC 3943160. PMID 23269374.
  3. ^ Yin Wu; Yehia Mechref; Iveta Klouckova; Anoop Mayampurath; Milos V. Novotny; Haixu Tang (2010). "Mapping site-specific protein N-glycosylations through liquid chromatography/mass spectrometry and targeted tandem mass spectrometry". Rapid Communications in Mass Spectrometry. 24 (7): 965–972. doi:10.1002/rcm.4474. PMID 20209665.
  4. ^ "GlyPID". indiana.edu.