Chlamydia Antibody Screening (Serum/Plasma) by Immunoassay
This test detects antibodies in your blood that your immune system produces in response to *Chlamydia trachomatis*, a common bacterial infection often spread through sexual contact. It helps identify past or current infection, even if you don’t have symptoms.
["This screening helps determine if you’ve been exposed to chlamydia, even when symptoms aren’t present."]
Key facts at a glance
- LOINC
- 38468-5
- Short code
- CHLMC
- Synonyms
- Chlamydia Ab CSF Ql
- Category
- chemistry
- Sample
- csf
- Container
- Sterile CSF collection tube (polypropylene, screw-cap); tube #2 or #3 recommended for microbiology/serology to minimize blood contamination
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–99 years
- Method
- Enzyme Immunoassay (EIA) or Immunofluorescence Assay (IFA) for detection of Chlamydia species antibodies
- CPT
- 86631
- SNOMED
- 313322005
- Specimen volume
- 1-2 mL of cerebrospinal fluid
- Stability
- Refrigerated (2-8°C): up to 7 days; Frozen (-20°C or below): up to 30 days for antibody testing. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 200
- TAT
- 24–72 hours
- Order
- routine
Why This Test Matters
Chlamydia is one of the most common sexually transmitted infections (STIs) in the U.S. and can cause serious health issues if untreated, such as pelvic inflammatory disease (PID) in women, infertility, or chronic pelvic pain. Early detection through antibody screening supports timely treatment and reduces long-term complications.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample (usually from your arm) in a clinic or lab. The test is quick and typically painless. If you’re pregnant, inform your healthcare provider before testing.
What the Test Results Mean
Results can be positive, negative, or inconclusive. A positive result means your body has likely been exposed to chlamydia at some point, but it doesn’t always indicate an active infection. A negative result suggests no recent exposure or infection. Follow-up testing may be recommended if you have symptoms or risk factors.
Next Steps After Testing
If your test is positive, your healthcare provider will guide you on treatment options, which usually involve antibiotics. If you’re sexually active, notify your partners to prevent spreading the infection. If you’re pregnant, discuss treatment options with your doctor to ensure safe outcomes for both you and your baby.
Reference range
Negative: No antibodies detected. Positive: Antibodies to Chlamydia species detected, indicating prior exposure or active infection.N/A
No special patient preparation required. Lumbar puncture is performed by a qualified healthcare provider under sterile conditions. Inform the patient of procedure risks including headache, bleeding, and infection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Chlamydia Antibody Screen
Frequently asked questions
What does a positive result indicate?
Can I get false-positive results?
How long does it take to 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