Chlamydia trachomatis Antibody, Qualitative (Serum/Plasma)
This test detects antibodies to *Chlamydia trachomatis*, a bacteria that can cause infections like chlamydia. Antibodies are your body’s immune response to the infection.
["Helps identify past or current chlamydia infection by checking for your immune system’s reaction to the bacteria."]
Key facts at a glance
- LOINC
- 45105-4
- Short code
- CHLAGAN
- Synonyms
- Chlamydia Ag Anal Ql
- Category
- chemistry
- Sample
- serum
- Container
- Sterile transport container or Dacron/flocked swab in viral transport medium (VTM) or specific Chlamydia transport medium
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 13–99 years
- Method
- Enzyme Immunoassay (EIA) for Chlamydia sp. antigen detection
- CPT
- 87320
- SNOMED
- 310861001
- Specimen volume
- Anal swab specimen; minimum volume sufficient for assay
- Stability
- Refrigerate at 2-8°C; stable for up to 24 hours. For prolonged storage, freeze at -70°C or below. Do not freeze at -20°C.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like unusual discharge, pain during urination, or if you’ve been exposed to chlamydia. It’s also used during routine screenings, especially for sexually active individuals. Some providers may order it for partners of someone diagnosed with chlamydia to prevent spread.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample (serum or plasma) via a simple venipuncture. Results are typically qualitative (positive/negative) rather than quantitative.
What the Results Mean
A positive result means your body has produced antibodies to chlamydia, suggesting past infection. A negative result means no detectable antibodies were found at this time. Remember, a negative result does not always mean you’re free of infection—other tests or follow-ups may be needed.
When You Might Need Follow-Up
If you test positive, your provider will guide you on next steps, which may include treatment (often with antibiotics) and retesting. If you test negative but have symptoms, other infections or conditions could be causing them—consult your provider for further evaluation.
Reference range
Negative (No Chlamydia sp. antigen detected)N/A
No special preparation required. Patient should avoid use of rectal medications, enemas, or lubricants for 24 hours prior to specimen collection. Specimen should be collected before initiation of antibiotic therapy when possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Chlamydia Antibody Test (Qualitative)
Frequently asked questions
What does a positive result mean?
Can I get this test if I’m pregnant?
How soon can I get results?
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