While previous theory has called for incorporating environmental assessment into the process of strategic job analysis as a precursor to applying selection methods (Singh, 2008), I argue that the method of new-member acquisition itself should be contingent on the nature of the environment.
To avoid the aforementioned side reactions, several parameters need to be optimized: (1) ratio of PTC-to-base-to-precursor, (2) selection of a less basic counteranion such as oxalate, bicarbonate, etc., (3) reaction temperature, and (4) the choice of leaving group.
More specifically, it has been reported that iTRAQ is sensitive to errors in precursor ion selection in comparison to ICAT and DIGE, suggesting mass spectrometer-related interference could introduce substantial random variation [ 32].
In order to gain sufficiently high fragment ion intensities, limited selectivity of precursor selection has to be addressed (e.g., isolation width = 2 or 3 u).
However, factors such as incomplete fragmentation (whereby not all the y- and b-ions are present in the spectrum), imprecise precursor ion selection due to overlapping peptide fragment masses, low signal-to-noise ratio and unpredicted post-translational modifications (PTMs) complicate the manual de novo sequencing.
Data were collected over a broad mass to charge (m/z) precursor ion selection scan range of 375 1,800, utilizing dynamic exclusion to minimize redundant selection of peptides previously selected for CID.
The mass window for precursor ion selection was set to ± 1 m/z.
For collision-induced dissociation, the collision cell was floated at 1 kV, the resolution of the precursor ion selection was set to 150 FWHM, and air was used as the collision gas at 5×10−7 Torr.
The isolation window for the precursor ion selection was set to 2.0 Th.
The MALDI SYNAPT was operated in V-mode, m/z range of 50 1000 and the quadrupole transmission window was set to 1 Da for precursor ion selection.
