Chlamydia Antibody Screening (Serum/Plasma)
This test detects antibodies in your blood that may indicate past or possible exposure to the chlamydia bacterium, a common sexually transmitted infection.
["This screening helps identify if you’ve been exposed to chlamydia, even if you don’t have symptoms."]
Key facts at a glance
- LOINC
- 5082-3
- Short code
- CHLAB
- Synonyms
- Chlamydia Ab Ser IA-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube without anticoagulant
- Units
- N/A
- Ref low
- 0.9
- Ref high
- 1.1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (Enzyme Immunoassay/EIA)
- CPT
- 86631
- SNOMED
- 10828004
- Specimen volume
- 1-2 mL of serum (minimum 0.5 mL)
- Stability
- Stable at room temperature for 8 hours; refrigerated (2-8°C) for 7 days; frozen (-20°C or below) for up to 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may recommend this test if you have symptoms of chlamydia (such as unusual discharge, pain during urination, or pelvic pain in women), if you’re sexually active and at higher risk (e.g., new or multiple partners), or as part of routine screening for sexually transmitted infections (STIs). It can also be used during pregnancy to check for infection.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm in a clinic or lab. The test is quick and typically done while you’re sitting or lying down.
What the Test Results Mean
A positive result means your blood contains antibodies against chlamydia, suggesting past or current infection. A negative result means no detectable antibodies were found at this time. Follow-up testing or treatment may be recommended based on your symptoms and risk factors.
Possible Side Effects or Risks
There are usually no side effects from a blood draw, but you might experience mild bruising, soreness, or swelling at the injection site. Rarely, there could be a slight reaction to the needle.
Reference range
Negative: <0.9 (antibody index or index value); Equivocal: 0.9-1.1; Positive: >1.1. Reference values vary by assay manufacturer.N/A
No fasting required. No special preparation needed prior to specimen collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Chlamydia Antibody Screen
Frequently asked questions
Chlamydia is a bacterial infection that can cause serious health issues if untreated, including pelvic inflammatory disease (PID) in women, infertility, or complications during pregnancy. Early detection through antibody screening helps guide treatment and prevent complications.
A positive result indicates you may have been exposed to chlamydia. Your healthcare provider will discuss next steps, which may include retesting, treatment, or further evaluation to address any symptoms or risks.
Yes, a negative antibody test means no antibodies were detected at this time, but you could still have an active chlamydia infection. If you have symptoms or are at risk, retesting or other diagnostic tests (like PCR) may be needed to confirm or rule out infection.
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 14, 2026. · Read our editorial policy