Chlamydia Antibody Screening Test (Serum)
This test detects antibodies in your blood that may indicate a past or current infection with *Chlamydia trachomatis*, a common sexually transmitted bacterium.
["This screening helps identify if you’ve been exposed to chlamydia, even if you don’t have symptoms."]
Key facts at a glance
- LOINC
- 45012-2
- Short code
- CHL-AB
- Synonyms
- Chlamydia Ab Ser Ql
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme Immunoassay (EIA) or Immunofluorescence Assay (IFA) for detection of antibodies against Chlamydia species
- CPT
- 86631
- SNOMED
- 1089001000119100
- Specimen volume
- 1-2 mL of serum
- Stability
- Serum stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why This Test Matters
Chlamydia is often asymptomatic, meaning you might not notice symptoms like pain, discharge, or unusual bleeding. Antibodies in your blood can signal an immune response to past or recent infection, helping healthcare providers assess exposure risk or confirm prior infection.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, typically drawn from your arm in a clinic or lab setting. Results are usually available within a few days.
How the Test Works
The test uses an immunoassay (a lab method that detects specific antibodies) to identify chlamydia-specific proteins in your serum. It’s not a direct test for the bacterium itself but helps track immune system reactions.
What the Results Mean
A positive result suggests you may have had chlamydia at some point, but it doesn’t confirm active infection. Follow-up testing (like a nucleic acid amplification test) may be needed to check for current infection.
Reference range
Negative: No detectable antibodies. Positive: Indicates presence of antibodies to Chlamydia species, suggesting prior exposure or current infection.N/A
No fasting required. Patient should inform clinician of any current antibiotic therapy, recent infections, or symptoms suggestive of chlamydial infection (e.g., urethral discharge, pelvic pain, conjunctivitis).
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Chlamydia Antibody Screen
Frequently asked questions
Can this test tell me if I have chlamydia right now?
What if my results are positive?
Does this test require fasting?
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