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

Performing a Background Run
When to Perform Applied Biosystems recommends running a background plate weekly or as often as
necessary depending on instrument use.
Purpose of
Background Runs
About the
Background
Component
A background run measures the ambient fluorescence in a background plate
containing deionized water. During the run, the 7900HT instrument conducts a
continuous scan of the plate for 2 minutes at 60 °C. Afterwards, the SDS software
averages the spectrum recorded during the run and is used to extract the resulting
spectral component to a calibration file. The software uses the calibration file during
subsequent runs to remove the background signal from the run data.
Because the background signal can change with instrument age, Applied Biosystems
recommends regenerating the Background component calibration every month.
Note Background runs can also be used to detect and troubleshoot sample block
contamination.
Fluorescence collected by the ABI PRISM 7900HT Sequence Detection System
includes a “background” component, a fluorescent signal that is inherent to the
system. The background component is a composite signal found in all spectral data
that consists of fluorescence from several sources including: the background
electronic signal, the sample block, the water within the consumable, and the plastic
consumable itself. Because the background signal can interfere with the precision of
SDS data, the 7900HT instrument has been engineered to minimize the background
signal. Additionally, the SDS software also algorithmically eliminates the background
signal from each fluorescent sample to maximize the instrument’s sensitivity (see
page A-5).
Materials Required The following materials are required to perform a background run:
Material Part Number
One of the following:
♦ Background Plate included in a ABI PRISM Sequence Detection
Systems Spectral Calibration Kit, or
♦ Make a background plate (requires the following)
See page D-4
– ABI PRISM® Optical 394- or 96-Well Reaction Plate
– ABI PRISM® Optical Adhesive Cover or ABI PRISM Optical Flat Caps
– Pipettor, 100-µL (with pipet tips)
Centrifuge, with plate adapter —
System Maintenance 7-13