ABI Prism® 7900HT Sequence Detection System ... - OpenWetWare

Setting the Baseline
and Threshold
Values for the Run
6-10 Real-Time Analysis
Before calculating absolute quantification values, the baseline and threshold values
must be set for all detectors present on the plate.
To set the baseline and threshold values for the run:
Step Action
1 Click the Results tab.
2
The software displays the contents of the Results tabbed page.
If the Amplification Plot is not visible, click the Amplification Plot button ( ).
The software displays the results of the sequence detection run in an amplification
plot of normalized reporter fluorescence (Rn ) versus threshold cycle (CT ).
3 From the Plot drop-down list, select Rn vs. Cycle.
The software plots the analyzed data in the graph of reporter fluorescence versus
cycle number.
4 Identify the components of the linear scale amplification plot and set the baseline so
that the amplification curve growth begins at a cycle number greater than the Stop
baseline cycle.
IMPORTANT Do not adjust the default baseline if the amplification curve growth
begins after cycle 15.
If the amplification plot looks like... Then...
the amplification curve begins after the
maximum baseline (cycle 15).
Do not adjust the baseline.
the maximum baseline is set too high.
Decrease the Stop baseline value by
clicking and dragging the right carrot to an
earlier cycle.
the maximum baseline is set too low.
Increase the Stop baseline value by clicking
and dragging the right carrot to a later cycle.