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HIV p24 Antigen Antibody Screen (Serum/Plasma)

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

This test checks for antibodies to the p24 protein of the human immunodeficiency virus (HIV), which may indicate past or current infection. It is often used as part of initial HIV screening.

Quick summary

["A simple blood test to help detect HIV antibodies, supporting early diagnosis and treatment planning."]

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

Key facts at a glance

LOINC
16978-9
Short code
HIV1 p24 Ab Ser-aCnc
Synonyms
HIV1 p24 Ab 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
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 This Test Measures

The test detects antibodies produced by your immune system in response to the p24 protein of HIV. These antibodies are part of your body’s defense against the virus. The presence of these antibodies suggests exposure to HIV, though they may take weeks to develop after infection.

How the Test Works

This test uses an immunoassay method to identify antibodies against the p24 protein. Blood is drawn from a vein, typically in your arm, and sent to a lab for analysis. The lab processes the sample to detect the presence of these antibodies, which are then measured and reported.

Sample Collection and Preparation

A small amount of blood is collected via a needle inserted into your arm. The blood is then separated into serum or plasma for testing. This process is quick and usually causes only minor discomfort.

When You Might Need This Test

Your healthcare provider may recommend this test if you have risk factors for HIV, such as unprotected sexual contact, shared needles, or other behaviors that increase exposure. It may also be part of routine testing for certain groups, like those with sexually transmitted infections or those living in high-prevalence areas.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HIV p24 Antibody Screen

Frequently asked questions

How long does it take to get results from this test?
Results from this test are typically available within 24 to 72 hours, depending on your healthcare facility’s processing times. Follow-up instructions from your provider will guide you on next steps if your results are positive or if further testing is needed.
Can I have this test if I have never been tested for HIV before?
Yes, this test can be used as part of initial HIV screening, even if you’ve never been tested before. It’s important to discuss your medical history and risk factors with your healthcare provider to determine the best approach for you.
What if my test results are positive?
A positive result on this test means your body may have antibodies to HIV, but it does not confirm the infection. Your healthcare provider will likely order additional tests, such as a confirmatory antibody test or viral load test, to determine if you are infected with HIV. Early diagnosis and treatment are crucial for managing the virus effectively.
  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