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

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

This test checks for antibodies to the human immunodeficiency virus (HIV), which your body makes in response to the virus. It helps determine if you’ve been exposed to HIV.

Quick summary

["An HIV antibody screen is the first step in diagnosing HIV infection."]

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

Key facts at a glance

LOINC
94343-1
Short code
Hu2 IgG Titr Ser IF
Synonyms
Hu2 IgG Titr Ser IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
8
Ref high
61
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82977
SNOMED
3110003
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 after exposure to HIV. These antibodies can appear in your blood within weeks to months after infection, though some people may test negative early in infection. The test uses an immunoassay method to identify these antibodies in serum or plasma.

How the Test Works

Your blood sample is tested to detect specific proteins (antibodies) that your body creates in reaction to HIV. If antibodies are present, the test can indicate past or current infection. This is not a test for the virus itself but for evidence of exposure.

Why It’s Done

Healthcare providers use this test to screen for HIV as part of routine check-ups, especially for high-risk groups (e.g., sexually active individuals, those with multiple sexual partners, or intravenous drug users). It may also be used during pregnancy to prevent mother-to-child transmission.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re pregnant, let your healthcare provider know before the test.

Reference range

Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HIV Antibody Screen

Frequently asked questions

What does a positive result mean?
A positive result indicates the presence of HIV antibodies, which means you may have been infected with HIV. You should contact your healthcare provider immediately for further testing and guidance on next steps, including treatment options and counseling.
Can I get false positives or false negatives?
False positives are rare but possible, especially if you’ve had a recent vaccination or exposure to other viruses. False negatives can occur if you tested too early after infection (within weeks to months). If your initial test is negative but you suspect exposure, repeat testing or additional confirmatory tests may be recommended.
How often should I get tested?
The CDC recommends HIV testing at least once every 6–12 months if you’re at high risk for infection. If you’re pregnant, you should get tested once during pregnancy. If you’re unsure about your risk, discuss testing with your healthcare provider—there’s no harm in getting tested regularly.
  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