Borrelia burgdorferi IgG Antibody, Serologic Test (Serum/Plasma)
This blood test detects antibodies to *Borrelia burgdorferi*, the bacterium responsible for Lyme disease. Antibodies develop after infection and can help confirm a past or current Lyme disease exposure.
["This test helps diagnose Lyme disease by checking for immune system responses to the Lyme bacterium."]
Key facts at a glance
- LOINC
- 31313-0
- Short code
- COXPH2
- Synonyms
- C burnet Ph2 Ab Ser-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top clot tube
- 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
- 12231000
- Specimen volume
- 1 mL serum (minimum 0.5 mL)
- Stability
- Stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 48–96 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms of Lyme disease, such as a bullseye rash (erythema migrans), flu-like illness, or joint/muscle pain. It may also be used if you’ve lived in or traveled to areas where Lyme disease is common and have been exposed to ticks.
What to Expect Before the Test
No special preparation is needed. A blood sample will be drawn from a vein, usually in your arm. You may feel a slight pinch, but it’s a quick process. If you’re on blood-thinning medication, let your provider know before the test.
What the Test Results Mean
Positive results indicate the presence of antibodies, suggesting past or current infection. However, false positives can occur, especially in people who’ve been vaccinated or exposed to other bacteria. Results may take several days to weeks to return.
Possible Side Effects
Most people experience mild discomfort or bruising at the injection site. Rarely, there may be a slight swelling or redness. If you develop fever, chills, or severe pain, contact your provider.
Reference range
Negative: <1:16; Equivocal: 1:16-1:32; Positive: ≥1:64. Phase 2 antibodies indicate acute or recent infection with Coxiella burnetii (Q fever).N/A
No special preparation required. Acute and convalescent serum samples (2-4 weeks apart) are recommended for accurate diagnosis of acute Q fever.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Borrelia IgG Antibody
Frequently asked questions
This test is critical for diagnosing Lyme disease, which can cause long-term complications if untreated, such as joint pain, nerve damage, or heart issues. Early detection improves treatment outcomes and reduces risks.
Yes, vaccination can produce false-positive results on this test. If you’ve been vaccinated, your provider may order additional tests or clarify the results.
Antibodies can persist for months to years after infection, but their levels may decrease over time. If symptoms return, retesting may be needed.
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