PerkinElmer QuantaSmart 1694267, Справочное руководство

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CHAPTER 5
68 PerkinElmer Life and Analytical Sciences
DPM Assays
A DPM assay allows you to quantitate a nuclide or nuclides within a sample. The
data is expressed as DPM (Disintegrations Per Minute). When DPM are being
calculated, the sample must be checked for quench. If a sample is not corrected
for quench, erroneous DPM results may be reported.
For each sample in a DPM assay, the instrument:
„
Measures the activity in a sample vial in Counts Per Minute (CPM).
„
Determines the level of quench via one of the Quench Indicating Parameters
(QIPs).
„
Interpolates the counting efficiency from a quench curve (plots % Efficiency
vs. QIP).
„
Calculates DPM, where DPM=CPM/Efficiency.
Depending on the TriCarb model, four different DPM assays are available:
Single, Dual and Triple DPM Assays allow you to count one, two or three nuclides
in a sample using one, two and three defined counting regions.
FS DPM (Full Spectrum DPM) Assays allow you to count two nuclides in a sample
using the full spectrum of the sample (no defined counting regions).
Performing a DPM Assay
The following tasks are required when performing a DPM Assay.
„
Calibrate the instrument, if necessary.
„
Define and run a Quench Standards Assay so that counting efficiency and
DPM can be determined for the samples.
„
Create a new assay choosing DPM Single, Dual or Triple as the assay type
and define the new assay parameters.
„
Save the assay, OR open an existing DPM assay and edit or review if
necessary.
„
Select a quench standards set for use with the sample nuclide(s).
„
Save the assay in the Assays folder of the Packard\TriCarb directory.
„
Associate (link) the assay parameters with a protocol and attach the
corresponding protocol flag to the first cassette to be counted.
„
Load the cassette(s) with vials and load the instrument with cassettes.
„
Start the instrument.