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Treponemal Antibody Test (Serological Screening for Syphilis)

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

This test detects antibodies to *Treponema pallidum*, the bacterium responsible for syphilis. It is used to screen for early or latent infections.

Quick summary

["This test helps identify syphilis by detecting the body’s immune response to the infection."]

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

Key facts at a glance

LOINC
75175-0
Short code
FIRSTTREPONEMALTESTRESULT
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
cdc-cs
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 *Treponema pallidum*. These antibodies appear after the infection has been present for some time, often weeks to months. The test is typically performed on serum or plasma from a blood sample.

Why It’s Done

Your healthcare provider may order this test if you have symptoms of syphilis (e.g., rashes, sores, or flu-like illness) or if you’ve been exposed to the bacteria. It’s also used as part of routine screening for sexually transmitted infections (STIs) or during pregnancy.

How the Test Works

The test uses an immunoassay method to detect antibodies against *Treponema pallidum*. If antibodies are found, it suggests past or current infection, though they may remain detectable even after treatment.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm for a blood draw. The process takes a few minutes, and you may feel slight discomfort.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is highly sensitive for syphilis and is often used as a first-line screening tool. However, it may not detect early infections (early syphilis) or infections in the early stages. A non-reactive result does not rule out syphilis, so follow-up testing may be recommended if symptoms persist or exposure is suspected.

Short name

Treponemal Antibody Test

Frequently asked questions

Will this test show if I have syphilis right away?
No, this test typically detects antibodies that develop weeks to months after infection. Early syphilis may not be detected by this test alone. If you suspect exposure, discuss your symptoms and history with your healthcare provider.
What if my test results are positive?
A positive result means your body has produced antibodies to *Treponema pallidum*. Further testing (such as a confirmatory treponemal test) will be needed to confirm syphilis. Treatment with antibiotics can cure syphilis if detected early.
Can I get syphilis from a positive test result?
No, a positive test result indicates an infection, not the test itself. If you’re concerned about exposure, talk to your healthcare provider about next steps, including treatment options.
  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