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Fluorescent Immunoassay for Anti-Viral Antibodies (e.g., Influenza Virus Neutralizing Antibodies)

Published: August 9, 2026Updated: August 16, 2026

This test measures antibodies your immune system produces in response to an influenza virus infection. It helps determine if you’ve been exposed to the virus and whether your body has developed immunity.

Quick summary

["Assists in diagnosing past exposure or immunity to influenza virus infection via antibody detection."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
31438-5
Short code
FLUAV IgM Ser-aCnc
Synonyms
FLUAV IgM Ser-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

The test detects specific antibodies (immunoglobulins) your immune system creates after encountering an influenza virus. These antibodies are part of your body’s defense mechanism and can indicate whether you’ve been infected or vaccinated against influenza.

Why It’s Done

Healthcare providers may order this test if you have symptoms of influenza (e.g., fever, cough, fatigue) or if you’ve been exposed to someone with influenza. It can also help assess immunity after vaccination or prior exposure.

Sample Collection and Preparation

A blood sample is drawn from a vein in your arm. The serum (liquid part of blood) is then tested using a fluorescent immunoassay method to identify the presence of specific antibodies.

What to Expect Before the Test

No special preparation is needed, but inform your provider if you’re on blood-thinning medications or have bleeding disorders. Avoid alcohol before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results suggest past exposure to influenza, indicating immunity. Negative results may mean you haven’t been exposed or vaccinated recently. This test is not used for diagnosing active influenza but can guide vaccination decisions or monitor immune response.

Short name

Influenza Antibody Test (FIA)

Frequently asked questions

Will this test show if I currently have the flu?
No, this test detects antibodies from past exposure or vaccination, not active infection. For diagnosing active flu, a viral test (e.g., rapid antigen or PCR) is needed.
How long does it take to get results?
Results are typically available within 24 to 48 hours, depending on lab processing times.
Can I get this test at home?
No, this test requires a blood sample collected by a healthcare professional in a clinical setting.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy