Chlamydia IgG Antibody (Serum) – Immunoassay
This test detects antibodies in your blood that your immune system produces in response to *Chlamydia trachomatis*, a common bacterial infection often causing sexually transmitted infections (STIs).
["Helps identify past exposure to chlamydia, even if symptoms are no longer present."]
Key facts at a glance
- LOINC
- 22183-8
- Short code
- Chlamydia IgG CSF-aCnc
- Synonyms
- Chlamydia IgG CSF-aCnc
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
What This Test Measures
The test looks for IgG antibodies, a type of immune protein your body makes after being exposed to chlamydia. Unlike IgM (which appears shortly after infection), IgG antibodies can stay in your system for months or years, indicating past infection rather than an active one.
Why It’s Ordered
Your healthcare provider may order this test if you have risk factors for chlamydia (e.g., multiple sexual partners, unprotected sex) or if you’ve had symptoms like unusual discharge, pain during urination, or pelvic pain—even if tests for active infection (like culture or PCR) came back negative.
Sample Collection and Preparation
A blood sample is drawn from a vein in your arm. The blood is processed to separate serum (the liquid part without clotting factors), which is then tested for IgG antibodies using an immunoassay method. This process is quick and typically done in a lab.
Interpretation and Results
Results are qualitative (positive/negative) rather than numeric. A positive result suggests you’ve likely been exposed to chlamydia at some point, but it doesn’t confirm an active infection. Follow-up testing may be needed if you’re at risk of complications or symptoms persist.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
While IgG antibodies indicate past exposure, they don’t always mean you’re immune to reinfection. Chlamydia can return, so ongoing precautions (like regular STI screenings and safe sex practices) are important. This test is often used alongside other tests (like PCR) to assess overall STI risk or history.
Short name
IgG Antibody to Chlamydia (Serum)
Frequently asked questions
Does this test show if I currently have chlamydia?
Can I get chlamydia again even if this test is positive?
What does a positive result mean for my health?
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