PerkinElmer QuantaSmart 1694267, Reference Manual

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ASSAYS
PerkinElmer Life and Analytical Sciences 85
Background Subtract
Mark this box to subtract background CPM from all samples. The background
value is established in one of three ways and is selected from the following:
1
st
Vial
The instrument counts the first vial in the cassette for either ten minutes or the
defined protocol count time (whichever is greater) and establishes a CPM value
for each region; these are the background values subtracted from each sample
within each region of the assay.
IPA
The instrument subtracts the background values established during the calibration
and Instrument Performance Assessment (IPA) procedures from the entire
spectrum of the samples. The background spectra are stored during these
procedures and are available for any counting region.
Manual
Enter the CPM values you would like the instrument to subtract from the entire
spectrum of the samples.
Note: In Quench Standards assays, the 1
st
Vial background
subtraction option is not available. Background subtraction is only
applied to the reported data for quench standards and has no
impact on the spectrum for each standard. Any background
subtraction that occurs in DPM assays will apply to the quench
standards used for the purpose of recalculating the quench curve
in the DPM assay.