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Borrelia burgdorferi IgG Antibody, Serum (Quantitative)

Published: August 9, 2026Updated: August 15, 2026

This test measures the presence of antibodies to *Borrelia burgdorferi*, the bacterium responsible for Lyme disease. Antibodies develop after infection and can help confirm past exposure.

Quick summary

["This test helps diagnose Lyme disease by detecting immune system responses to the Lyme bacterium."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 15, 2026Editorial policy

Key facts at a glance

LOINC
7830-3
Short code
COX2G
Synonyms
C burnet Ph2 IgG Ser-aCnc
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top tube
Units
N/A
Ref low
0
Ref high
1
Critical range
— – 200 N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
Immunofluorescence Assay (IFA)
CPT
86638
SNOMED
313330003
Specimen volume
1-2 mL serum
Stability
Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
Hemolysis max
200
Lipemia max
100
Icterus max
50
TAT
24–96 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 bull’s-eye rash (erythema migrans), flu-like symptoms, or joint/muscle pain. It’s also used to check for past infection in people with ongoing symptoms or a history of tick exposure.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample drawn from a vein, typically in your arm. The sample is sent to a lab for antibody testing.

What the Test Results Mean

Positive results indicate the presence of antibodies, suggesting past infection. Negative results mean no detectable antibodies, but other tests (like Western blot) may be needed for confirmation. False negatives can occur early in infection or with certain conditions.

Common Reasons for Testing

This test is often used as a screening tool to identify Lyme disease, especially in areas with high tick activity. It’s not always definitive on its own, so results may be followed up with additional testing if needed.

Reference range

Negative: <1:16; Equivocal: 1:16; Positive: ≥1:32 (titer)N/A

Specimen: serum

No special preparation required. Specimen should be collected before initiation of antibiotic therapy when possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Borrelia IgG Antibody (Serum)

Frequently asked questions

What symptoms might indicate Lyme disease?
Symptoms of Lyme disease can include a rash (often a red, ring-shaped rash called erythema migrans), fever, chills, headache, joint or muscle pain, fatigue, or swollen lymph nodes. If you’ve had a tick bite and develop these symptoms, especially in a region where Lyme disease is common, this test may be recommended.
How soon after infection can this test detect antibodies?
Antibodies typically develop within 1 to 4 weeks after infection, but some people may not test positive until weeks or months later. Early-stage testing may yield false negatives, so healthcare providers may recommend retesting or additional testing if symptoms persist.
Can this test be used to monitor treatment progress?
While this test can confirm past infection, it’s not typically used to monitor treatment directly. Instead, healthcare providers may rely on symptom improvement, resolution of physical findings, or repeat testing with other methods (like PCR or Western blot) to assess treatment effectiveness.
  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 15, 2026. · Read our editorial policy