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Chlamydia Antibody Test by Serological Screening (Serum)

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

This test detects antibodies in your blood that may indicate past or potential exposure to *Chlamydia trachomatis*, a common bacterial infection often spread through sexual contact.

Quick summary

["Helps assess risk for or history of chlamydia infection."]

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

Key facts at a glance

LOINC
31766-9
Short code
Chlamydia Ag Stl Ql
Synonyms
Chlamydia Ag Stl Ql
Category
chemistry
Sample
stool
Container
Clean container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
87110
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

What This Test Measures

The test looks for antibodies produced by your immune system in response to *Chlamydia trachomatis*. These antibodies can appear after infection, even if symptoms were mild or absent. This screening is typically used to identify exposure rather than confirm an active infection, which would require additional testing.

Why It Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms of chlamydia (e.g., unusual discharge, pain during urination) or if you are at higher risk (e.g., sexually active without protection, new sexual partners). It may also be part of routine screening for sexually transmitted infections (STIs).

Sample Collection and Preparation

A blood sample is drawn from a vein in your arm. The serum portion is separated and tested for antibodies using an immunoassay method. This process is quick and typically done in a lab setting.

What to Expect Before the Test

No special preparation is needed. You may have some mild discomfort or bruising at the injection site, but this usually resolves quickly. Avoid alcohol or certain medications that could interfere with results for 24 hours before testing if instructed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Chlamydia Antibody Screen (Serum)

Frequently asked questions

How long does it take to get results?
Results are usually available within 1–3 business days, depending on lab processing times. Your healthcare provider will contact you directly with the outcome.
What does a positive result mean?
A positive test indicates your body has produced antibodies against *Chlamydia trachomatis*, suggesting past exposure. This does not confirm an active infection but may prompt further evaluation if symptoms or risk factors are present.
Can I get chlamydia even if my test is negative?
Yes, a negative result means no detectable antibodies at this time, but you could still be infected. Chlamydia can be asymptomatic, and exposure may not always trigger an immune response immediately. Follow-up testing or prevention measures (e.g., condoms) are recommended if at risk.
  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