Background Runs - Applied Biosystems 7900HT User Manual

Background Runs

Background
Troubleshooting
Table
Isolating
Sample Block
Contamination
Applied Biosystems 7900HT Fast Real-Time PCR System and SDS Enterprise Database User Guide
Table 8-2 Troubleshooting Background Runs
Observation
Software will not extract
background data
Background is too high
(=>2500)
aFluorescent standard units – The measure of amplitude displayed along the Y-axis of the
Background Plot.
Signals exceeding 2500 FSU are considered outside the limit of normal background
fluorescence and indicates that the either the background plate or the sample block
module may be contaminated.
1. If not already open, open the plate document for the background run.
2. In the toolbar, click
The SDS software displays the raw data pane for the background run.
3. Select all wells in the plate document.
4. Inspect the raw background data for an aberrant spectral peak or peaks.
Wells producing raw spectra that exceed 2500 FSU are considered irregular and
could be contaminated. The following figure illustrates the raw data produced
by a run on a sample block module containing a contaminated well.
Possible Cause
During setup, the wrong
plate type was assigned to
the plate document
Background is too high
(≥ 2500 FSU a )
Sample block
contamination
Background plate
contamination
(Hide/Show System Raw Data Pane).
DRAFT
September 1, 2004 11:39 am, CH_Trouble.fm

Background Runs

Recommended Action
Run a new background
plate document with the
proper plate type setting.
See below.
1. Construct and run a new
background plate.
2. See "Isolating
Sample Block
Contamination" below.
Possible contamination
8-9