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Antibody Detection to Influenza Virus Nucleoprotein (Serum/Plasma)

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

This test measures antibodies your immune system produces in response to exposure to the influenza virus. It helps determine if you’ve been infected or vaccinated.

Quick summary

["Helps track past exposure or immunity to flu strains."]

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

Key facts at a glance

LOINC
101424-0
Short code
FLUAV H3 RNA Resp Ql NAA+probe
Synonyms
FLUAV H3 RNA Resp Ql NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
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

Why This Test Is Done

Doctors may order this test to investigate unexplained flu-like symptoms, evaluate immune response after vaccination, or assess exposure risk in high-risk groups (e.g., healthcare workers, elderly). It’s also used in research or outbreak investigations.

What to Expect Before the Test

No special preparation is needed. A blood sample is drawn from a vein in your arm. You may feel a brief pinch, but it’s quick and painless. If you’re on blood thinners, let your provider know before testing.

What the Results Mean

Positive results indicate your immune system has detected the virus’s nucleoprotein, suggesting past infection or vaccination. Negative results mean no detectable antibodies at this time. Interpretation depends on clinical context (e.g., timing since exposure).

Common Causes of Positive Results

Positive results can occur after natural flu infection, vaccination (including seasonal flu shots), or rare cross-reactions with other viruses. False positives are uncommon but possible if you’ve had recent exposure or a related illness.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test supports diagnosis of past infection, guides vaccination strategies, or confirms exposure in outbreaks. It’s particularly useful for monitoring immune response in high-risk populations or research settings. Results should always be reviewed by your healthcare provider in the context of your symptoms and medical history.

Short name

Influenza Nucleoprotein Antibody

Frequently asked questions

Will this test show if I have the flu right now?
No. This test detects antibodies produced after exposure, not active infection. For current flu symptoms, you’d need a rapid antigen test or viral PCR test instead.
Can I get this test at home?
No. This is a blood test typically done in a lab or clinic. A healthcare provider will draw your blood, and results are usually reported within days.
What if my results are positive but I don’t feel sick?
Positive results could mean you had a mild infection you didn’t notice or were exposed to the virus without symptoms. Your provider may recommend follow-up testing or monitoring based on your situation.
  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