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Chlamydia IgG Antibody (Serum/Plasma) – Confirmatory Test

Published: August 9, 2026Updated: August 16, 2026

This test detects antibodies to *Chlamydia trachomatis*, a common bacterial infection that can affect the reproductive system, eyes, or respiratory tract. It helps confirm past exposure rather than an active infection.

Quick summary

["This test checks for immunity to chlamydia from past infection, not current illness."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
16591-0
Short code
Chlamydia IgG CSF IF-aCnc
Synonyms
Chlamydia IgG CSF IF-aCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82784
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why This Test May Be Ordered

Your healthcare provider may recommend this test if you have symptoms of past chlamydia exposure (e.g., persistent sore throat, eye irritation, or reproductive concerns) or if you’ve been exposed to the bacteria. It’s also used in screening for conditions linked to prior infection, such as pelvic inflammatory disease or reactive arthritis.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample (usually drawn from your arm) in a serum or plasma tube. Avoid alcohol for 24 hours before testing if instructed, as it may affect results.

What the Test Results Mean

A positive result means your body has produced antibodies against chlamydia, indicating past infection. A negative result suggests no detectable antibodies, meaning either you’ve never been infected or the infection cleared without leaving detectable antibodies.

Common Reasons for Testing

This test is often used in: - Screening for conditions linked to chlamydia (e.g., chronic pelvic pain, infertility). - Evaluating individuals with symptoms of reactive arthritis or eye infections. - Assessing exposure history in sexually transmitted disease (STD) counseling.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Chlamydia IgG Antibody

Frequently asked questions

Why might this test be important for my health?
If positive, it confirms past exposure but does not indicate whether the infection was treated. This test helps guide further evaluation for chronic conditions or assesses immunity status in high-risk groups (e.g., sexually active individuals).
Can this test detect an active chlamydia infection?
No, this test only detects antibodies, which appear after the infection has resolved. For active infection, a culture, nucleic acid amplification test (NAAT), or other diagnostic methods are used.
How long do results take?
Results are typically available within 2–5 business days, depending on lab processing times. Follow-up with your provider for interpretation and next steps.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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