PerkinElmer QuantaSmart 1694267, Reference Manual

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ASSAYS
PerkinElmer Life and Analytical Sciences 69
Quench Set
The Quench Set field is displayed only in DPM Assays. This field displays the
quench set you selected for the Sample Nuclide in the assay. When using a
quench set, counting efficiency is determined for each sample in the assay. By
selecting the Constant Quench option in this field, counting efficiency will only be
determined for the first sample in the assay. The counting efficiency for this
sample is used to calculate DPM for all the samples in the assay. The Constant
Quench option is advantageous since it results in a reduction in the amount of
time required to count the samples in an assay.
FS DPM Assay
The Full Spectrum DPM method is used for regionless counting of dual label
samples. It uses the Quench Indicating Parameters, Spectral Index of the Sample
(SIS) and transformed Spectral Index of the External standard (tSIE), as well as a
spectral unfolding technique to separate the composite spectrum of the sample.
The composite spectrum is separated into two component spectra, each of which
is the result of a different nuclide. Spectrum unfolding yields the actual CPM for
each nuclide and a quench correlation curve comparing SIS vs. tSIE and Efficiency
vs. tSIE is used to determine the DPM of the unknown samples.
Maximum accuracy with this method is obtained when the concentration of
nuclides in the sample falls in the range of 50:1 to 1:8 (low energy to high energy
nuclide). The quench standards used for FS DPM should be of the same chemistry
and geometry as your unknown samples.