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HIV Antibody and Antigen P24 Screening and Confirmation Panel (Serum/Plasma)

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

This test checks for HIV antibodies and the HIV p24 antigen in your blood to help detect the virus that causes AIDS. It’s used as part of routine screening or when you have symptoms that might suggest HIV infection.

Quick summary

Early detection helps manage the virus more effectively and supports better long-term health outcomes.

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

Key facts at a glance

LOINC
85037-0
Short code
HIV 1 + 2 Ab + HIV 1 p24 Ag Pnl SerPl IA
Synonyms
HIV 1 + 2 Ab + HIV 1 p24 Ag Pnl SerPl IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 includes two key components: HIV antibodies (detected via immunoassay methods) and the HIV p24 antigen (detected via immunoassay). Antibodies develop after infection, while the p24 antigen appears earlier in the infection timeline. Together, they help confirm or rule out HIV infection.

Why It’s Done

Healthcare providers use this panel to screen for HIV in asymptomatic individuals, evaluate those with symptoms like fever, fatigue, or unexplained weight loss, or as part of pre-exposure prophylaxis (PrEP) monitoring. It’s also used in high-risk populations or after potential exposure.

Sample Collection and Preparation

Blood is drawn from a vein in your arm, and the sample is processed into either serum (liquid after clotting) or plasma (liquid after centrifugation). This blood sample is then tested in a lab using sensitive immunoassay techniques to detect the presence of HIV markers.

Test Methodology

The test relies on immunoassay methods (such as chemiluminescent immunoassay or fluorescence immunoassay) to identify HIV antibodies and the p24 antigen. These methods use antibodies specific to HIV to bind with the virus markers, triggering a detectable signal in the lab.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

HIV Screening Panel

Frequently asked questions

If the test is positive, it indicates a likely HIV infection, and further diagnostic testing (like viral load testing) is needed to confirm and guide treatment. A negative result means the virus was not detected in this sample, but repeated testing may still be recommended if you have risk factors or symptoms.
What does a positive result mean?
A positive result suggests HIV antibodies or the p24 antigen are present, which strongly indicates an active HIV infection. You’ll need follow-up testing, such as viral load testing, to confirm the diagnosis and determine the best treatment plan. Your healthcare provider will guide you through next steps, including counseling and potential referral to an infectious disease specialist.
What if my test is negative but I suspect I might have been exposed?
A negative result means the virus was not detected in this sample, but HIV can sometimes take weeks to months to develop detectable antibodies. If you suspect exposure, discuss with your provider about retesting after 3–6 months or using a combination of tests (like antibody and antigen tests) for earlier detection.
If you’re at high risk for HIV (e.g., unprotected sex with multiple partners, sharing needles, or having other risk behaviors), your provider may recommend testing every 3–12 months, depending on your risk factors. Regular testing is especially important if you’re on PrEP or have symptoms that could indicate infection.
  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