This protocol was developed by Cepheid Medical/Scientific Affairs, to provide assistance to customers who are performing verification studies of the Xpert Xpress SARS-CoV-2/Flu/RSV test, thereby referred to as Xpress SARS CoV2-/Flu/RSV. It concerns one aspect of the verification process, which is the testing of known positive and negative samples. It is the laboratory director’s responsibility to ensure that a complete and adequate verification study is performed in accordance with federal, state, and local laws.*
The objective of this protocol is to facilitate verification studies of the Xpress SARS-CoV-2/Flu/RSV test by describing how to use inactivated organisms from ZeptoMetrix (ZeptoMetrix, Buffalo, NY) to prepare mock or simulated nasopharyngeal (NP), Nasal (NS) swabs, and Nasal Aspirate/Washes (NA/W) for verification testing.
ZeptoMetrix manufactures NATtrol inactivated organisms that will provide positive and negative results for verification studies with Xpress SARS-CoV-2/Flu/RSV test. These materials are supplied in a stable liquid form as individual controls.
The NATtrol inactivated viruses available are shown in Table 1 and include strains of SARS-CoV-2, Influenza A, Influenza B, Respiratory syncytial virus (RSV) B, and Coxsackievirus, all in a purified protein matrix that mimics the composition of a clinical specimen. The NATFRC-6C control material is not used in the creation of simulated or contrived specimens but may be used for future training or blinded proficiency investigations.
Note: Before you start, please read through the procedure in its entirety and print out Verification Charts (1 and 2) Xpert Xpress SARS-CoV2/Flu/RSV by clicking on the paperclip icon and selecting the PDF files (Figure 1). The charts contain specimen numbering/labeling information that is used throughout the procedure. Also, remember to change gloves between processing specimens.