Applied Biosystems 3500, Руководство пользователя

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Setting
Description
Min. Peak Half Width Specify the smallest half peak width at full height for peak detection. The range is 2 to
99 data points.
Polynomial Degree Adjust to affect the sensitivity of peak detection. You can adjust this parameter to detect
a single base pair difference while minimizing the detection of shoulder effects and/or
noise.
The peak detector calculates the first derivative of a polynomial curve fitted to the data
within a window that is centered on each data point in the analysis range.
Using curves with larger polynomial degree values allows the curve to more closely
approximate the signal and, therefore, captures more of the peak structure in the
electropherogram.
Peak Window Size Enter a window width in data points for peak detection sensitivity. If more than one
peak apex is within the window, all are labeled as a single peak. Note the following:
• The maximum value is the number of data points between peaks.
• The Peak Window Size setting is limited to odd numbers.
To increase peak detection sensitivity: Increase polynomial degree, decrease peak
window size.
To decrease peak detection sensitivity: Decrease polynomial degree, increase peak
window size.
Slope Thresholds Peak
Start and End
Not recommended for use with AmpF
ℓ
STR ™ kit data.
• Peak Start—The peak starts when the first derivative (slope of the tangent) in the
beginning of the peak signal before the inflection point becomes equal to or
exceeds the “Peak Start” value. This threshold is set to 0 by default, which means
that the peak will normally start at the leftmost point where the slope of the
tangent is closest to 0° (horizontal line). A value other than 0 moves the peak start
point toward its center. The value entered must be non-negative.
• Peak End—The peak ends when the first derivative (slope of the tangent) in the
end of the peak signal after the inflection point becomes equal to or exceeds the
“Peak End” value. This value is set to 0 by default, which means that the peak will
normally end at the rightmost point where the slope of the tangent is closest to 0°
(horizontal line). A value other than 0 moves the peak end point toward its center.
The value entered in this field must be non-positive.
Chapter 7 Manage library resources
QC protocols library (primary analysis—HID)
7
3500/3500xL Genetic Analyzer User Guide—Data Collection Software v3.1 189