Ethos Laboratories SARS-CoV-2 MALDI-TOF Assay

Performance Characteristics

• Entire test performed in-house
• The entire testing of the Ethos Laboratories SARS-CoV-2 MALDI-TOF Assay is performed in-house.

Analytical specificity for the Ethos Laboratories SARS-CoV-2 MALDI-TOF Assay was evaluated by analyzing the ZeptoMetrix NATtrol Respiratory Verification Panel (ZeptoMetrix, Catalog # NATRVP-NNS).This is a qualitative-only control that is formulated to Ct specifications using a ZeptoMetrix in-house RT-PCR assay. Nineteen various organisms were tested in singlicate (n=19) against the NI, N2, N3, ORF1, and ORF1ab genes, and all organisms were negative for all five genes. For analytical accuracy, 107 samples were assessed as part of this evaluation; fifty-three confirmed positive and fifty-four confirmed negative nasopharyngeal swab samples that were originally tested through a RT-PCR workflow using the CDC 2019-nCOV Real-Time RT-PCR EUA and supplied by the Kentucky Division of Laboratory Services (KDLS). Samples were extracted using the KingFisher Flex Purification system using the MagBind Viral DNA/RNA Kit as per the manufacturer’s procedure. 52 out of 54 negative samples yielded negative results (96.3%), and 52 out of 53 positive samples yielded positive results (98.1%), with overall agreement achieving 97.2%. For analytical precision, studies were conducted by spiking known concentrations of SARS-CoV-2 culture fluid control into negative nasal swab VTM matrix. The samples were then extracted and analyzed using to the Ethos Laboratories SARS-CoV-2 MALDI-TOF Assay. Twenty replicates of a predetermined LoD concentration (1 TCID50/mL) were analyzed, with 100% of samples returning a positive results of at least 2 SARS-CoV-2 genes.

LIMITATIONS • The use of this assay as an in vitro diagnostic under the FDA Emergency Use Authorization (EUA) is limited to laboratories that are certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), 42 U.S.C. § 263a, to perform high complexity tests. • Use of this assay is limited to personnel who are trained in the procedure of RT-PCR and mass spectrometry. Failure to follow these instructions may result in erroneous results. • The Ethos Laboratories SARS-CoV-2 MALDI-TOF Assay can be used with the specimen types listed in the Intended Use statement. Other specimen types have not been evaluated and should not be used with this assay. • Samples must be collected, transported, and stored using appropriate procedures and conditions. Improper collection, transport, or storage of specimens may hinder the ability of the assay to detect the target sequences. • Extraction and amplification of nucleic acid from clinical samples must be performed according the specified methods listed in this procedure. Other extraction approaches and processing systems have not been evaluated. • False-negative results may arise from: − Improper sample collection − Degradation of the viral RNA during shipping/storage − Using unauthorized extraction or assay reagents − The presence of RT-PCR inhibitors − Mutation in the SARS-CoV-2 virus − Failure to follow instructions for use • False-positive results may arise from: − Cross contamination during specimen handling or preparation − Cross contamination between patient samples − Specimen mix-up − RNA contamination during product handling Ethos Laboratories SARS-CoV-2 MALDI-TOF Assay Page 14 of 25 • The effect of vaccines, antiviral therapeutics, antibiotics, chemotherapeutic or immunosuppressant drugs have not yet been evaluated. • Please note, Negative results do not preclude infection of SARS-CoV-2 virus and should not be the sole basis of a patient management decision. A positive result indicates detection of nucleic acid from the relevant virus. Nucleic acid may persist even after the virus is no longer viable. • Laboratories are required to report all positive results to the appropriate public health authorities.

Minimal microbe load test can detect

Is proficiency testing performed for this test? HelpWhether the test undergoes periodic internal or external evaluation of the accuracy of test results. Lab-provided.

Yes

Method used for proficiency testingHelpMethod used for external or internal evaluation of the accuracy of test results. Lab-provided.

Intra-Laboratory

PT ProviderHelpProvider used for proficiency testing. Lab-provided.

College of American Pathologists, CAP

PT Description

External proficiency test performed by Ethos Labs for CAP.

FDA Category Designation

EUA - Emergency Use Authorization