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Fluorescent Immunoassay for Antigen Detection in Respiratory Specimen (e.g., SARS-CoV-2)

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

This test detects the presence of a viral protein from the coronavirus responsible for COVID-19 in your respiratory sample, such as nasal or throat swabs.

Quick summary

["Quickly checks for active infection with a simple at-home or clinic test."]

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

Key facts at a glance

LOINC
22825-4
Short code
FLUAV Ag Spec Ql ID
Synonyms
FLUAV Ag Spec Ql ID
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-diffusion
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

How the Test Works

The test uses a fluorescent immunoassay to identify specific viral proteins. When you provide a sample (like a nasal or throat swab), antibodies in the test bind to any virus present. A light-sensitive detector then measures the fluorescence to indicate whether the virus is detected.

What to Expect

Results are typically available in 10–30 minutes. A positive result suggests recent infection, but it may not be as accurate as lab tests for diagnosing COVID-19.

When You Might Need This Test

Doctors may recommend this test for rapid screening before gatherings, travel, or if you have symptoms like fever, cough, or fatigue. It’s not used for monitoring long-term infection status.

Limitations and Considerations

This test is designed for quick, point-of-care use but has lower sensitivity than lab-based PCR tests, especially in the early or late stages of infection. False negatives can occur if the sample is taken too early or if the virus is low.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: This test helps identify active COVID-19 infections quickly, supporting decisions about isolation, treatment, or exposure control. However, it should not replace confirmatory lab testing for critical situations.

Short name

COVID-19 Rapid Antigen Test

Frequently asked questions

Why might I get a false negative result?
A false negative can happen if the test was taken too soon after exposure, if the viral load is low, or if the sample wasn’t collected correctly. If you develop symptoms later, retesting may be needed.
Can I use this test at home?
Yes, many versions of this test are available over-the-counter for home use. Follow the manufacturer’s instructions carefully to ensure accurate results.
Is this test covered by insurance?
Coverage depends on your plan and reason for testing. Some insurers may cover rapid antigen tests for exposure or travel, while others may require a prescription or lab-based testing instead.
  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