Applied Biosystems Data Explorer 4 Series, User Manual

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Appendix C Data Explorer Toolbox (Visual Basic Macros)
C-12 Applied Biosystems
C
2. If desired, click Label Immonium Ions.
NOTE: Label immonium ions before selecting a
reference peak and starting the search. If you click
Label Immonium Ions after selecting a reference peak,
the amino acid labels applied to the spectrum are
erased, and mass labels are reapplied.
3. Select a peak in the Spec Peak List, then click Set
Selected Peak as Reference.
The software evaluates mass differences between the
reference peak (labeled with *) and all other peaks, and
labels any differences that correspond to amino acid
residues.
4. Select a result peak from the results list, if desired, then
continue the sequence search by clicking the Search
Down or Up buttons.
The newly selected peak is now labeled as the reference
peak, and mass differences minus (if you click Down) or
plus (if you click Up) are labeled if they correspond to an
amino acid residue. You can generate the complete
sequence ladder by appending new results to existing
results.
NOTE: When you search using reference peaks
selected from the Sequence Results list, new results
retain the label of the original reference peak, and new
labels are appended. For example, if you select
433.08(+Thr)(*) as the reference, results are listed as
362.13(+Thr)(-Ala), 331.98(+Thr)(-Thr), and
334.07(+Thr)(-Val). The (+Thr) immediately following
the mass corresponds to the selected reference (the
result of the original search). The residue following
(+Thr) is the residue that corresponds to the mass
difference between the mass and the reference mass.