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HIV P24 Antigen Qualitative, Plasma/Serum

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

This test detects the presence of a protein (P24 antigen) produced by the HIV virus in your blood. It helps determine if you have an active HIV infection.

Quick summary

["This test can help identify early HIV infection by detecting the virus’s protein components in your bloodstream."]

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

Key facts at a glance

LOINC
33630-5
Short code
HIV PI gene Mut Det Islt
Synonyms
HIV PI gene Mut Det Islt
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
86701
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 the Purpose of This Test?

The HIV P24 antigen test is primarily used to screen for early HIV infection. It can detect HIV as soon as the virus starts multiplying in your body, sometimes even before antibodies develop. This test is often used in combination with other tests, such as HIV antibody tests, for accurate diagnosis.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is then sent to a lab where it is tested for the presence of the P24 antigen using an immunoassay method. This process helps identify whether the virus is actively replicating in your system.

What Does a Positive Result Mean?

A positive result means the test detected the P24 antigen, indicating that you likely have an active HIV infection. This result should be confirmed with additional testing, such as an HIV antibody test, to ensure accuracy. Always follow up with your healthcare provider for further guidance.

What Does a Negative Result Mean?

A negative result means the P24 antigen was not detected in your blood sample at the time of testing. This does not definitively rule out HIV infection, as the virus may not yet be producing detectable levels of the antigen. If you suspect you have been exposed to HIV, discuss further testing with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Why Is This Test Important?

Short name

HIV P24 Antigen Test

Frequently asked questions

Why Was I Asked to Take This Test?
You may have been asked to take this test if you have recently been exposed to HIV, have symptoms of infection, or are part of a screening program for early detection. Early diagnosis is crucial for managing HIV and improving long-term health outcomes.
What Should I Expect After the Test?
After your blood sample is collected, you can typically resume normal activities immediately. Results are usually available within a few days to a week, depending on the lab’s processing time. Your healthcare provider will discuss the results with you and recommend next steps, such as additional testing or treatment options.
How Often Should I Get This Test?
The frequency of this test depends on your medical history, risk factors, and healthcare provider’s recommendations. If you are at high risk for HIV, your provider may advise regular testing. Follow their guidance to ensure proper monitoring and care.
  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