SARS-CoV-2 and Flu A+B Combo Test Kits
With many respiratory illnesses presenting with similar symptoms, convenient Applied Biosystems™, Quidel™, and BD SARS-CoV-2 and Flu A+B combo test kits help save time and money by enabling clinicians to detect either of the infectious agents with the same test. SARS-CoV-2 and Flu A+B combo test kits require the collection of only a single specimen from patients in order to make a differential diagnosis from the results of just one assay, eliminating the need for multiple costly tests.
Different types of COVID-19 and flu test kits use different testing methodologies. They can either be antigen-based or use molecular techniques. Diagnostic tests for viral antigens or RNA indicate a current infection.
Antigen assays typically detect nucleocapsid proteins from a virus like SARS-CoV-2 or Flu A+B. These tests may use direct or indirect fluorescent immunoassay, immunochromatographic, or lateral flow techniques to produce rapid and accurate results, typically in less than 30 minutes.
Antigen tests incorporate antibodies specific to the viral antigens or device. If antigens are present in the sample, they react and bind to the antibodies, forming antibody-antigen complexes. The complexes migrate across the test strip to a reaction area where secondary antibodies or other reagents are embedded in the membrane.
When the complex reaches the “test” area of the device, it reacts to create a color or other change that indicates a positive result. Most antigen tests also have an internal “control” area to indicate the successful and complete migration of the antibody-antigen complex. Results may be read visually or with the help of a reader or analyzer.
Antigen assays can be CLIA-waived and typically produce results in less than 30 minutes, making them suitable for outpatient or point-of-care use.
Some multiplex molecular assays used in COVID-19 and flu test kits can detect influenza viral nucleic acids and therefore help distinguish influenza virus infection from other respiratory pathogens. These tests are also useful for managing severely immunosuppressed patients or for identifying the cause of an institutional outbreak of respiratory illness.
Molecular assays take advantage of the polymerase chain reaction (PCR) process to make copies of any viral ribonucleic acids (RNA) that has collected from the patient. Even minute amounts of viral RNA can be duplicated or amplified to produce enough material for testing. Various amplification methods may be used, including reverse transcription polymerase chain reaction (RT-PCR).