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COVID-19 (SARS-CoV-2) Antigen Test, Qualitative — Nasal Specimen, Laboratory Test

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

A laboratory test that detects SARS-CoV-2 antigen in a nasal specimen to help identify a current COVID-19 infection.

Quick summary

["A positive result suggests that you currently have a SARS-CoV-2 infection."]

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

Key facts at a glance

LOINC
96084-9
Short code
HEDIS MY 2020 Qn Ur Alb Lab Test
Synonyms
HEDIS MY 2020 Qn Ur Alb Lab Test
Category
urine
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 is this test?

This qualitative antigen test looks for protein from the SARS-CoV-2 virus in a nasal specimen. It is used to help determine whether a person has a current COVID-19 infection.

Why might I need this test?

You may need this test if you have COVID-19 symptoms, were exposed to someone with the infection, or are required to test before travel, work, school, or a medical procedure.

How is the test performed?

A healthcare professional or laboratory worker collects a nasal specimen, usually with a swab, and tests it for SARS-CoV-2 antigen. The result is reported as positive, negative, or sometimes invalid.

How do I prepare for the test?

Follow the laboratory or clinician's instructions about which specimen will be collected. Tell the healthcare professional if you have recently used nasal spray or received nasal medication, because these can sometimes affect the result.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A positive result generally indicates that SARS-CoV-2 antigen is present and may indicate a current infection. A negative result does not completely rule out COVID-19, especially early after exposure or when the amount of virus is low. If you have symptoms or a concerning exposure, ask your clinician whether repeat testing or a nucleic acid test is appropriate.

Short name

COVID-19 Antigen Test

Frequently asked questions

Does a positive COVID-19 antigen test mean I am contagious?
It indicates that you are infected, but it does not by itself determine how much virus you have or how contagious you are. Follow current public-health and clinician guidance about isolation and protecting others.
Can I use a home COVID-19 test instead?
Home rapid antigen tests can detect the same viral antigen, but their collection method and instructions may differ from this laboratory test. Follow the specific directions provided with your test.
What should I do if my result is negative but I have symptoms?
A false-negative result is possible, particularly early in an infection. Contact a healthcare professional about repeat testing or a molecular COVID-19 test if your symptoms continue or your exposure risk is high.
  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