Skip to content

Borrelia burgdorferi IgG antibody by Immunofluorescence Assay (serum/plasma)

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

This test detects antibodies in your blood that your immune system produces in response to *Borrelia burgdorferi*, the bacterium responsible for Lyme disease. It helps diagnose infections caused by tick bites.

Quick summary

["This test checks for past or current Lyme disease exposure by measuring specific antibodies in your blood."]

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

Key facts at a glance

LOINC
9708-9
Short code
COXPH1
Synonyms
C burnet Ph1 IgG Titr Ser
Category
chemistry
Sample
serum
Container
Serum separator tube (SST), red-top tube, or gold-top tube
Units
N/A
Ref low
0
Ref high
1
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Immunofluorescence Assay (IFA)
CPT
86638
SNOMED
302002005
Specimen volume
1-2 mL serum (minimum 0.5 mL)
Stability
Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or lower): 30 days. Avoid repeated freeze-thaw cycles.
Hemolysis max
100
Lipemia max
50
Icterus max
20
TAT
48–168 hours
Order
routine

What This Test Measures

The test uses immunofluorescence to identify IgG antibodies against *Borrelia burgdorferi* antigens. These antibodies develop after your body encounters the bacterium, often weeks to months after infection. The method detects these antibodies by binding them to labeled markers under a microscope.

How the Test Works

Your blood sample is processed to separate serum or plasma, where the test looks for IgG antibodies. If antibodies are present, they bind to specific *Borrelia* antigens on a microscopic slide, creating visible markers that indicate a positive result.

Why It Matters

IgG antibodies remain in your system for months or years after infection, making this test useful for diagnosing Lyme disease in early or late stages. It can also help confirm a diagnosis if symptoms are unclear or if other tests are inconclusive.

When You Might Need This Test

Your healthcare provider may recommend this test if you’ve had a tick bite, have symptoms like fever, rash, joint pain, or neurological issues, or if you live in an area with high Lyme disease risk. It’s often used alongside other tests, such as culture or PCR, for confirmation.

Reference range

Negative: <1:200; Equivocal: 1:200; Positive: ≥1:200 (titer endpoint reported as reciprocal of highest dilution with positive reactivity)N/A

Specimen: serum

No fasting required. No special patient preparation needed. Acute and convalescent serum samples (2-4 weeks apart) are recommended for seroconversion assessment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results suggest past or current *Borrelia burgdorferi* infection, but false positives can occur due to cross-reactions with other bacteria or prior vaccinations. Negative results don’t always rule out Lyme disease, especially if testing is done too early. Results should be interpreted alongside clinical findings and other diagnostic tests.

Short name

IgG Antibody to Lyme Disease Spirochete

Frequently asked questions

How soon after infection might I get a positive result?
IgG antibodies typically appear 4–6 weeks after infection, but some people may take longer. Early testing (e.g., IgM antibodies) may be more sensitive right after exposure, but IgG testing is often used for confirmation in later stages.
Can I get this test at home?
No, this test requires a blood sample drawn by a healthcare professional in a clinical setting. Home tests for Lyme disease antibodies are limited and not FDA-approved for the same purpose.
Does this test show active Lyme disease?
This test primarily detects past or chronic infection, not active disease. For active Lyme disease, other tests like culture, PCR, or early IgM antibodies may be needed to confirm current infection.
  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