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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.

An internal control line helps ensure that the rapid test has been executed properly, that the kit reagents are performing appropriately, and that adequate flow has occurred through the test strip. Another fluorescent line should form at the Control position on the test strip each time a specimen or control is tested. If no control line is detected, the test will be reported as invalid by Sofia. The Sofia Influenza A+B FIA gives you accuracy and confidence in rapid testing.

Sofia Influenza A+B FIA – the easy-to-use rapid influenza test kit – is one of a growing menu of fluorescent antibody tests available for use on Sofia. This high-quality, qualitative fluorescent test can be used as an aid in the rapid differential diagnosis of acute influenza A and influenza B viral infections.

When testing with Sofia Influenza A+B FIA, a single patient sample may also be used to test with Sofia RSV FIA.

Features & Benefits

CLIA waived for nasal and nasopharyngeal swabs

Easy to perform testing

Compatible with RSV Extraction Reagent

A single sample can be used to run both Sofia Influenza A+B and Sofia RSV

Dual work modes

Adjusts to your volume fluctuations

Self-contained test cassette

Clean, easy to use and dispose of

Fixed-volume pipette

Collects and dispenses correct amount of sample needed for testing

Objective result

Eliminates the subjectivity of a visual result

All components included in kit

Ready to use with Sofia, no need for additional equipment

Room temperature storage

No refrigerator space needed. Rapid influenza tests can be run immediately as needed.

Product Specifications

Product Spec NameProduct Spec Data
Sample type

Nasal swab, nasopharyngeal swab, nasopharyngeal aspirate/wash

Time to results

15 minutes

Kit storage conditions

Room temperature (15°C to 30°C/59°F to 86°F)


Positive and negative

Nasal Swab Sensitivity*

A: 90%, B: 89%

Nasopharyngeal Swab Sensitivity*

A: 97%, B: 90%

Nasopharyngeal Aspirate/Wash Sensitivity*

A: 99%, B: 88%

Nasal Swab Specificity*

A: 95%, B: 96%

Nasopharyngeal Swab Specificity *

A: 95%, B: 97%

Nasopharyngeal Aspirate/Wash Specificity*

A: 96%, B: 96%

Shelf life

24 months from date of manufacture

Transport Media Compatibility

Copan Universal Transport Media, Hank’s Balanced Salt Solution, M4, M4-RT, M5, M6, Modified Liquid Stuarts, Saline, Starplex Multitrans

CLIA Complexity

Waived for nasal and nasopharyngeal swab samples, moderate for nasopharyngeal aspirate/wash

*Refer to Package Insert for additional performance claims.

Ordering Information

Catalog NumberDescriptionKit Size / Case Size
20218 US
20254 XUS

Test Kit


Posters and Publications

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