Syphilis serology: Treponemal antibody detection (qualitative, donor-specific)
This test checks for antibodies to *Treponema pallidum*, the bacterium responsible for syphilis. It helps determine if you’ve been exposed to the infection.
["A positive result may indicate past or current syphilis infection; results alone don’t confirm diagnosis without additional testing."]
Key facts at a glance
- LOINC
- 75173-5
- Short code
- DATEOFFIRSTTREPONEMALTEST
- Synonyms
- —
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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
This test detects antibodies produced by your immune system in response to *Treponema pallidum*. Antibodies are proteins your body makes to fight infections. If present, they suggest exposure to the bacteria, though they may remain detectable even after treatment. The test is qualitative, meaning it only tells you if antibodies are present (positive) or not (negative), not the exact amount.
Why It’s Ordered
Your healthcare provider may order this test to screen for syphilis, especially if you have symptoms like skin rashes, sores, fever, or muscle aches. It’s also used in routine testing for sexually transmitted infections (STIs) or during pregnancy to check for syphilis.
How the Test Works
A blood sample is taken from a vein in your arm. The lab analyzes it to detect antibodies against *Treponema pallidum*. The result is reported as positive or negative, with no numeric value provided for antibody levels.
What to Expect Before the Test
No special preparation is needed. You may have a small bruise or needle site soreness afterward, but this is normal. If you’re pregnant or have a bleeding disorder, let your provider know before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive result means your body has detected antibodies to syphilis bacteria, which could indicate past infection or ongoing exposure. However, syphilis can be treated with antibiotics if caught early. A negative result means no detectable antibodies were found in this sample, but repeated testing may be needed if you have symptoms or risk factors. Always follow up with your healthcare provider for interpretation and next steps.
Short name
Treponemal Test (Qualitative)
Frequently asked questions
How long does it take to get results?
Can I have false positives or negatives?
Does this test replace other syphilis tests?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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