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HIV p24 Antigen Antibody Screening Test (Serum/Plasma)

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

This test detects antibodies to the p24 protein of the human immunodeficiency virus (HIV), helping identify if you’ve been exposed to HIV. It’s part of HIV screening to check for infection.

Quick summary

["A simple blood test to check for HIV antibodies that may indicate past or current infection."]

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

Key facts at a glance

LOINC
9664-4
Short code
HIV1 p24 Ab Ser Ql IB
Synonyms
HIV1 p24 Ab Ser Ql IB
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ib
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 looks for antibodies against the p24 protein, a key component of HIV. These antibodies develop after your body encounters the virus, though they may take weeks to months to appear. The test helps determine if you’ve been exposed to HIV, even if you’re not yet showing symptoms.

Why It’s Done

Your healthcare provider may recommend this test if you’re at higher risk for HIV (e.g., unprotected sex, shared needles, or living with someone infected), as part of routine screening, or if you have symptoms that could suggest HIV (e.g., fever, fatigue, or swollen lymph nodes). It’s also used as part of initial HIV testing in many healthcare settings.

How the Test Works

A small blood sample is taken from your arm and sent to a lab. The serum or plasma is tested using an immunoassay method to detect HIV antibodies. This method is highly sensitive and specific, helping to identify potential infection with high accuracy.

What to Expect Before the Test

No special preparation is needed. You may have a slight bruise or soreness at the injection site, but this usually goes away quickly. If you’re on blood-thinning medication, let your provider know before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HIV p24 Antibody Screen

Frequently asked questions

What does a positive result mean?
A positive result means your blood test detected antibodies to HIV, which could indicate past exposure to the virus. This doesn’t confirm HIV infection immediately, so further testing is usually recommended to confirm or rule out HIV. Your provider will guide you on next steps, such as follow-up tests or counseling.
Can I get HIV from this test?
No, you cannot get HIV from this blood test. The test involves a small sample of blood, and the process follows strict safety protocols to prevent any risk of transmission.
How soon after exposure can I get tested?
HIV antibodies may take weeks to months to develop after exposure. Some testing guidelines recommend waiting at least 3 months for screening, but early testing (as little as 4 weeks after exposure) may be done if you’re at high risk. Your provider will determine the best timing 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