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Human Immunodeficiency Virus (HIV) Antibody Screening by Immunoassay (Serum/Plasma)

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

This test detects antibodies to HIV, the virus that can cause AIDS, in your blood or plasma. It helps determine if you’ve been exposed to the virus.

Quick summary

["This screening identifies potential HIV exposure, not active infection, and is part of routine or risk-based testing."]

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

Key facts at a glance

LOINC
57977-1
Short code
HIV 2 p16 Ab Ser Ql IB
Synonyms
HIV 2 p16 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 produced by your immune system in response to HIV. These antibodies develop after exposure but may take weeks to months to appear. The immunoassay method detects these antibodies using a highly sensitive process.

How the Test Works

Your blood or plasma sample is analyzed to identify specific antibodies against HIV. If antibodies are found, it suggests past or recent exposure, though further testing (like confirmation) is needed to confirm HIV infection.

Why It’s Done

Doctors may order this test if you have risk factors for HIV (e.g., unprotected sex, shared needles, or HIV-positive partners) or as part of routine screening (e.g., for pregnant women, sexually active adults). It’s not a diagnostic test for active HIV but flags potential exposure.

What to Expect

You’ll provide a blood sample (usually drawn from your arm) in a clinic or lab. Results are typically ready within 24–48 hours. If positive, follow-up testing (like a confirmatory HIV antibody test) is required to confirm infection.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HIV Antibody Screen (Serum/Plasma)

Frequently asked questions

Why might I need this test?
This test helps identify people who may have been exposed to HIV but haven’t yet developed symptoms. Early detection allows for monitoring, prevention strategies (like pre-exposure prophylaxis), or linkage to care if needed. A positive result doesn’t mean you’re infected—it only means antibodies were detected, which requires further evaluation.
What does a positive result mean?
A positive screening result means your test detected HIV antibodies, which could indicate past exposure. However, this test alone isn’t definitive for HIV infection. Your doctor will likely order additional confirmatory tests (e.g., Western blot or fourth-generation HIV antibody/antigen tests) to confirm or rule out HIV.
Can I get false positives?
Yes, rare false positives can occur due to cross-reactions with other viruses (e.g., hepatitis) or certain medications. If your screening test is positive, your doctor will repeat tests to ensure accuracy. False negatives are also possible if tested too early after exposure (antibodies may not yet be detectable).
  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