Chapter 3 Peak Detection and Labeling

Charge state not displayed

3

If no charge is displayed, there are a few possible causes:

•Peaks are more than 1 Da apart.

•Filter width is set too high to detect other isotope peaks.

•The maximum charge state for charge state determination is set lower than the charge state of the peak.

•Charge state determination parameters are set such that peaks are determined to have no charge. See Section 3.2.5, Charge State Determination and Examples.

•Peaks are not from the same isotope species.

NOTE: If you set %Base Peak Intensity or %Max Peak Area too low (described on page 3-20),noise peaks can be detected, and charge states can be incorrectly labeled.

3-60 Applied Biosystems