LabChip GX/GXII User Manual

Software Reference 159Peak Find Tab (Continued)PlateSettingsMinimumPeak HeightMinimumPeak WidthSlopeThresholdInflectionThresholdStart TimeEnd TimeFilter WidthBaselinePlateauPolynomialOrderThis window contains the following options:Table 1. Plate Peak Find SettingsFunctionSpecifies the height limit below which a peak is not detected. Foreach peak, the difference between the peak start time and the peakapex must be greater than the Min Peak Height value.Specifies the limit (in seconds) for the peak width. Peaks narrower intime than this value are not detected.Represents the amount of change in absorbance units over timerequired to indicate that a peak has occurred. This setting is used todetect the leading and trailing edges of a peak. Increasing this settingmay cause broad rolling bumps to be ignored or merge multiplebumps into a single peak. Decreasing this setting will broaden thepeaks’ width and potentially pick up broad bumps as peaks. See“Peak Identification” on page 260 for more information.Represents the value that the slope minimum must be below totrigger a splitting of the peak. As the threshold is increased, morepeak splitting occurs. See “Inflection Threshold Example” onpage 254 for more information.Specifies the time after the start of a run when the first peak will bedetected (any peaks appearing before this time are ignored). The Geland Graph views will not plot data earlier than this time.Specifies the time after which peak detection stops. The Gel andGraph views will not plot data beyond this time.Specifies the width, in seconds, of the low pass filter to be convolvedwith the data. The width of this filter should be about 6 samples wide(i.e. 0.1 sec for 60 Hz sampling). If this setting is too large, peaks willdevelop spurious side lodes (ringing) due to over-filtering.Specifies a baseline selection parameter for peak finding. The signalis at baseline whenever the slope of the data is less than the slopethreshold setting (positive or negative) for longer than the BaselinePlateau. This rejects brief, low slope areas such as in between nonbaseline-resolvedpeaks.A filter algorithm is used to filter the data, increasing the signal-tonoiseratio. The data is convolved with a polynomial of this order toproduce filter data and a filter slope and decrease the background orbaseline noise and/or spikes in the signal. This value is read only.P/N 127170 Rev. 00 LabChip GX User Manual Caliper Life Sciences, Inc.