Instruction Manual

14
Specimen Result Interpretation for Pooled Specimens
nCoV-N1
nCoV-N3
IPC
Interpretation
Actions
ND
ND
Within +/- 3 Ct of
Negative Control
NOT DETECTED
Report to public health authorities.
DET
DET
Not Applicable (+/-)
POOLED
POSITIVE – DO
NOT REPORT
Repeat each constituent specimen in the pool
as a separate unpooled specimen.
Only one of two SARS-
nCoV-
2 targets are
Detected
Not Applicable (+/-)
POOLED
INCONCLUSIVE –
DO NOT REPORT
Repeat each constituent specimen in the pool
as a separate unpooled specimen.
ND
ND
Undetermined or IPC
out of range (>3Ct)
INVALID
Repeat each constituent specimen in the pool
as a separate unpooled specimen.
Quality Control
Run/assay acceptability criteria:
One replicate of the positive control and one replicate of the negative control are tested in each batch. Each control is
processed as a sample, through nucleic acid isolation and amplification/detection. Controls results (detection cycle or Ct)
are generated for the two SARS-CoV-2 targets, and the Internal Control target. Acceptable control results for the SARS-
CoV-2 and internal control are required for the run to be acceptable. An example of acceptable control results is shown in
the table below. If the Positive Control criteria are not met, the batch is invalid and all specimens must be repeated. If the
Negative Control has a Ct value < 40.00 (and has a valid amplification curve) for one or more of the SARS-CoV-2 targets,
then this control is invalid. This indicates possible contamination of prepared samples. Positive patient results cannot be
reported. Positive specimens on this run must be repeated. Negative specimens may be reported given that all other assay
run criteria are met.
Examples of Acceptance Criteria for Controls
(Detection cycle target ranges for controls)
Control
nCoV-N1
nCov-N3
IPC
nCoV Positive
26.85-32.85
26.20-32.20
26-32*
nCoV Negative
Not Detected
Not Detected
26-32*
*Acceptance range for IPC is determined by negative control value in each run ± 3 Ct
Limitations
1. All users, analysts, and any person reporting diagnostic results should be trained to perform this procedure by a competent
instructor. They should demonstrate their ability to perform the test and interpret the results prior to performing the assay
independently. Quest will limit the distribution of this device to only those users who have successfully completed training
provided by Quest.
2. Performance of the test has only been established in upper and lower respiratory specimens (such as nasopharyngeal or
oropharyngeal swabs, sputum, tracheal aspirates, and bronchoalveolar lavage/wash).
3. Negative results do not preclude SARS-CoV-2 infection and should not be used as the sole basis for treatment or other
patient management decisions. Optimum specimen types and timing for peak viral levels during infections caused by
SARS-CoV-2 have not been determined. Collection of multiple specimens (types and time points) from the same patient
may be necessary to detect the virus.
4. A false negative result may occur if a specimen is improperly collected, transported or handled. False negative results
may also occur if amplification inhibitors are present in the specimen or if inadequate numbers of organisms are present in
the specimen. Positive and negative predictive values are highly dependent on prevalence. False negative test results are
more likely when prevalence of disease is high. False positive test results are more likely when prevalence is moderate to
low.
5. Do not use any reagent past the expiration date.
6. If the virus mutates in the rRT-PCR target region, SARS-CoV-2 may not be detected or may be detected less predictably.