IgG Antibody to Borrelia burgdorferi (Lyme Disease) by Immunoassay
This test detects antibodies in your blood that your immune system produces in response to the bacteria causing Lyme disease, carried by ticks.
["Helps diagnose Lyme disease infection by identifying your immune system’s reaction to the bacteria."]
Key facts at a glance
- LOINC
- 111305-9
- Short code
- COXPH2G
- Synonyms
- C burnet Ph2 IgG Msmt Ser
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube; plain serum preferred. Avoid hemolyzed, lipemic, or icteric specimens when possible.
- Units
- N/A
- Ref low
- 16
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunofluorescence Assay (IFA)
- CPT
- 86638
- SNOMED
- 122460008
- Specimen volume
- 1-2 mL serum
- Stability
- Stable for 7 days at 2-8°C; for extended storage, freeze at -20°C or colder. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
What This Test Measures
The test looks for IgG antibodies specific to *Borrelia burgdorferi*, the bacterium responsible for Lyme disease. These antibodies develop after your body has been exposed to the bacteria, usually weeks to months after infection. The presence of these antibodies suggests past or ongoing infection, though they may not appear immediately after exposure.
How the Test Works
Your blood sample is tested using an immunoassay method, which detects the IgG antibodies against the Lyme bacteria. This method is highly sensitive and specific for identifying these antibodies in your serum.
When You Might Need This Test
A Lyme IgG antibody test is often recommended if you have symptoms of Lyme disease (such as fever, rash, or joint/muscle pain) after a tick bite, especially in areas where Lyme disease is common. It may also be used to confirm a diagnosis in people with persistent symptoms or after treatment for Lyme disease.
Symptoms and Risk Factors
Lyme disease symptoms can include flu-like illness (fever, chills, fatigue), a characteristic bull’s-eye rash (erythema migrans), and neurological or cardiac issues in advanced stages. Risk factors include living or traveling in tick-infested regions, spending time outdoors without protection, or having had a tick bite.
Reference range
Negative: <1:16; Equivocal: 1:16-1:32; Positive: >1:32. Phase 2 IgG antibodies indicate past exposure or chronic Q fever infection.N/A
No special preparation required. Patients should inform their healthcare provider of any recent antibiotic use, particularly tetracyclines or fluoroquinolones, which may affect antibody response.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Lyme IgG Antibody
Frequently asked questions
When can I expect results?
What does a positive result mean?
Can I get Lyme disease from a positive test?
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 15, 2026. · Read our editorial policy