The Sofia Influenza A+B Fluorescent Immunoassay (FIA) uses advanced immunofluorescence-based lateral-flow technology to detect influenza A and influenza B viral nucleoprotein antigens in nasal and nasopharyngeal swab and nasopharygeal aspirate/wash specimens taken directly from symptomatic patients.

The Sofia Influenza A+B FIA involves the disruption of influenza A and B viral antigens. To perform the rapid influenza A and B test, the patient specimen is placed in the Reagent Tube, during which time the virus particles in the specimen are disrupted, exposing internal viral nucleoproteins. After disruption, the specimen is dispensed into the Cassette sample well. From the sample well, the specimen migrates through a test strip containing various unique chemical environments. If influenza A or B viral antigens are present, they will be trapped in a specific location.

Sofia will scan the test strip and measure the immunofluorescent signal by processing the results using method-specific algorithms and display the test results (Positive, Negative, or Invalid) on its display screen. The test results can also be automatically printed on an integrated printer if this option is selected.