HIV p24 antigen test
Quick answer: This blood test looks for p24, a protein of the HIV virus that appears early in infection. Doctors may order it to detect a very recent HIV infection before antibodies have formed.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
How the test is done
- 1A nurse explains the test and checks your consent
- 2A vein on your arm is cleaned
- 3A needle draws blood into a tube
- 4The lab tests for the HIV p24 protein
What your results can mean
Reading your report
The report usually says positive, negative or borderline; a positive result often needs a confirmatory test, so discuss it with your doctor.
If the result is outside the usual range
A positive result can point to an early HIV infection, before antibodies have formed, and needs confirmation. A negative result does not rule out HIV, as p24 is only detectable for a short time early on.
Who usually has this test
People with a possible recent exposure or symptoms of early HIV infection such as fever, rash and swollen glands.
Risks and aftercare
No special aftercare; results are shared in private.
Names and options
Also called: p24 antigen, HIV p24
Listed by the hospital as
- HIV P 24 ANTIGEN, SERUM
Questions about this test
When is p24 antigen useful?
p24 rises in the first few weeks after infection, before antibodies appear. Many modern HIV tests combine p24 with antibody testing for this reason.
Why can p24 turn negative later?
Once antibodies form, they bind p24 and lower the level in the blood. That is why it is mainly used to detect early infection.
What follows a positive p24 test?
Your doctor will arrange confirmatory HIV tests, often including a viral load test, before any diagnosis is made.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
Waiting area
IVF lab
This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.