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Chapter 3 Algorithms
Size-Calling Methods (Classic and Advanced Modes)
Global Southern Method
Overview
This method is similar to the Least Squares method in that it
compensates for standard fragments that may run anomalously. The
method creates a best-fit line through all the available points, and
then uses values on that line to calculate the fragment values.
Figure 3-19 Global Southern Method
Global Southern
Method Equations
How the Global
Southern Method
Works
52
Equation
Description
L = [ c ⁄ ( m – m0 ) ] + L0
Attempts to describe the reciprocal
relationship between the mobility, m,
and the length, L0, of the standard
fragments.
∑ i { Li – [ c ⁄ ( ( mi – m0 ) + L0 ) ] }2
The fitting constants L0, m0, and c
are calculated by a least-squares fit
to minimize the left side quantity.
All points in the standard are weighted equally, and the curve is not
constrained to go through any specific point. The software can
analyze a large range of fragment sizes with this method. For best
results, use a standard that brackets all the fragments of interest.
GeneMapper® Software Version 4.1 Reference and Troubleshooting Guide