DRAFT
September 1, 2004 11:39 am, CH_Real-Time.fm
Chapter 6 Analyzing Real-Time Data
6-18 Applied Biosystems 7900HT Fast Real-Time PCR System and SDS Enterprise Database User Guide
Automatic
Threshold and
Baseline
Determination
The
SDS software features a proprietary AutoC
T
algorithm that can be used to
automatically generate baseline and threshold values for individual detectors. The
algorithm calculates baseline and threshold parameters for a detector based on the
assumption that the data exhibits the “typical” amplification curve shown in
Figure 6-7.
Figure 6-7 Typical Amplification Curve
Experimental error (such as contamination, pipetting inaccuracy, and so on) can
produce amplification curves that deviate significantly from the typical data shown
above. The data from these irregularities can affect the AutoC
T
algorithm by causing
it to generate incorrect baseline and threshold parameters for the associated detector.
For this reason, Applied Biosystems strongly recommends reviewing all baseline and
threshold parameters determined by the AutoC
T
algorithm following analysis of the
study data
.
Linear phase
Cycle
∆R
n
Geometric phase
Background
Baseline
Plateau phase