Applied Biosystems 7500 - Background Fluorescence; Guidelines for Calibration

Chapter 6 Analyzing Data in an RQ Study
Adjusting the Baseline and Threshold
Applied Biosystems 7300/7500/7500 Fast Real-Time PCR System Relative Quantification Getting Started Guide 67
Notes
6
Threshold Set Correctly
The threshold is set in the exponential phase of the
amplification curve.
Threshold settings above or below the optimum
increase the standard error of the replicate groups.
Threshold Set Too Low
The threshold is set below the exponential phase of
the amplification curve. The standard error is
significantly higher than that for a plot where the
threshold is set correctly. Drag the threshold bar up
into the exponential phase of the curve.
Threshold Set Too High
The threshold is set above the exponential phase of
the amplification curve. The standard error is
significantly higher than that for a plot where the
threshold is set correctly. Drag the threshold bar down
into the exponential phase of the curve.