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HIV-1 Antibody Screening by Immunoassay (Serum/Plasma)

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

This test checks for antibodies to the human immunodeficiency virus (HIV) in your blood or plasma. Antibodies develop after exposure to HIV, typically within weeks to months.

Quick summary

["Detects early HIV exposure to guide next steps in care and testing."]

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

Key facts at a glance

LOINC
21009-6
Short code
Deprecated HIV1 Ser IB-Imp
Synonyms
Deprecated HIV1 Ser IB-Imp
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 identifies HIV-1 antibodies using an immunoassay method. This means it detects specific proteins (antibodies) your immune system produces in response to HIV. If antibodies are found, it suggests past or potential current infection.

How the Test Works

A small blood sample is drawn and tested in a lab. The immunoassay detects antibodies against HIV-1 by measuring their presence in your serum or plasma. Results are reported as positive or negative.

Why It Matters for You

A positive result means further testing (like a confirmatory HIV antibody test) is needed to confirm infection. A negative result does not rule out HIV if you’ve recently been exposed.

When You Might Need This Test

This screening test is often used as part of routine testing for sexually active individuals, those with risk factors (like shared needles or unprotected sex), or as part of pre-exposure prophylaxis (PrEP) monitoring.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HIV Antibody Screen

Frequently asked questions

Why was I asked to take this test?
Your healthcare provider may recommend this test if you have symptoms of HIV (like fever, fatigue, or swollen lymph nodes), have risk factors for infection, or are part of a screening program.
What does a positive result mean?
A positive result means your body has detected HIV antibodies, which may indicate past or current infection. You’ll need follow-up testing to confirm and begin appropriate care.
Can I still be at risk if my test is negative?
Yes, HIV testing is not 100% accurate immediately after exposure. If you’ve had recent exposure, retesting after 3 months is recommended for accurate results.
  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