DRAFT
September 25, 2007 1:07 am, 4376782_Maintain_the_System.fm
Chapter 6 Maintain the System
Regular Maintenance
Applied Biosystems StepOne
™
and StepOnePlus
™
Real-Time PCR Systems
Installation, Networking, and Maintenance Guide
94
Notes
Perform a Background Calibration
Perform a background calibration monthly, or as often as necessary, depending on
instrument use.
Materials
Required
•
Background plate from the spectral calibration kit for your instrument
:
– StepOne
™
Real-Time PCR System Spectral Calibration Kit (PN 4371433)
– StepOnePlus
™
Real-Time PCR System Spectral Calibration Kit (PN 4371435)
Note: Alternatively, create a background plate as described in “How to Create a
Background Plate” on page 99.
• Powder-free gloves
• Safety glasses
• Centrifuge with reaction plate adapter
• StepOne system cable, yellow (from the system packing kit)
Calibration
Guidelines
• Make sure the centrifuge you use is clean. Before centrifuging, wipe down the
bucket using a tissue.
• Handle the calibration plates with care to prevent contamination. To avoid
contaminating the reaction plate, do not place plates on a lab bench. Always return
the calibration plate to its original bag.
Purpose of the
Calibration
A background calibration measures the level of background fluorescence in the
instrument. During a background calibration run, the system:
• Performs continuous reads of a background plate containing PCR buffer for 10 min
at 60 ° C.
• Averages the spectra recorded during the run and extracts the resulting spectral
component to a calibration file.
The StepOne
™
software uses the calibration file during subsequent runs to remove the
background fluorescence from the run data.
Background Fluorescence
Fluorescence data collected by the system includes a fluorescent spectral component
inherent to the system, commonly referred to as background fluorescence. This
background fluorescence is a composite signal found in all signal data that consists of
fluorescence from several sources, including:
• Background electronic signal
• Contaminants in the sample block(s)
• The plastic consumable (plates and caps)