Product Manual
60061-7 (2021-01) Accula SARS-CoV-2 IFU 15
testing with sequences carrying this mutation show showed a potential for reduced
sensitivity. Please see Table 2.
N gene Reverse Primer
34768 of 35556 complete SARS-CoV-2 genome sequences share 100% homology to
the Reverse Primer.
35470 of 35556 complete SARS-CoV-2 genome sequences share 100% homology
Detection Probe
35435 of 35556 complete SARS-CoV-2 genome sequences share 100% homology to
the Detection Probe.
Capture Probe
35497 of 35556 complete SARS-CoV-2 genome sequences share 100% homology to
the Capture Probe.
In silico analysis revealed that the forward primer is predicted to be bound to the mismatch template at the annealing/extension
temperatures of the assay.
Table 2. Three Accula SARS-CoV-2 test cassette lots were used to test performance with a perfect primer match synthetic
template (Perfect Match (GGG)) or a synthetic template carrying the variant sequence (Mismatch Template (AAC)).
Results Summary for Three Cassette Lots at LoD
Concentration (copy/mL)
1200
Cassette Lot
2011A099
2011C105
2011A1102
Perfect Match Template (GGG)
19/20 (95%)
20/20 (100%)
20/20 (100%)
Mismatch Template (AAC)
20/20 (100%)
17/20 (85%)
18/20 (90%)*
*One invalid result was obtained and repeated, yielding a valid result
Analytical Specificity – Exclusivity (Cross Reactivity)
The table below summarizes the findings of in silico exclusivity analysis examining the homology between the indicated organisms and
the Accula SARS-CoV-2 Test primers and probes. Potential interactions are noted where primer homology exceeds 75%. SARS-CoV is
the only organism identified as potentially cross-reactive by in silico analysis. While the primer binding sites are well conserved between
sequenced isolates of SARS-CoV and SARS-CoV-2, the capture and detection probe binding regions share only 70% and 65% homology
respectively. Probe homology with the consensus of a 226 sequence SARS-CoV alignment is listed in Table 3. Based only on sequence
analysis, we cannot rule out the possibility that the Accula SARS-CoV-2 Test may cross-react with SARS-CoV. However, the low
prevalence of SARS-CoV renders the observation of cross-reactivity unlikely. Indeed, SARS-CoV has not been detected in the human
population since 2004.
In addition to in silico analysis, the Accula SARS-CoV-2 Test will be challenged with nucleic acids isolated from human coronaviruses
OC43, NL63, HKU1 and 229E to confirm the test does not cross-react with these human coronaviruses.
In Silico Analysis of Exclusivity for the Accula SARS-CoV-2 Test
Organism
Homology
SARS-CoV
Forward primer 93.5% homology with SARS-CoV Consensus
Reverse primer 90.3% homology SARS-CoV Consensus
Detection probe 65% homology with SARS-CoV Consensus
Capture probe 70% homology with SARS-CoV Consensus
MERS-CoV
No alignment found
Human coronavirus 229E
No alignment found
Human coronavirus OC43
No alignment found
Human coronavirus HKU1
No alignment found
Human coronavirus NL63
No alignment found
Adenovirus
No alignment found
Human Metapneumovirus
No alignment found
Parainfluenza virus 1-4
No alignment found
Influenza A & B
No alignment found
Enterovirus
No alignment found
Respiratory Syncytial virus
No alignment found
Rhinovirus
No alignment found
Chlamydia pneumoniae
No alignment found
Haemophilus influenza
No alignment found