Borrelia burgdorferi IgG Antibody (Serum/Plasma) - Fluorescent Antibody Test

What This Test Measures

The test looks for specific antibodies (IgG) produced by your immune system in response to *Borrelia burgdorferi*. These antibodies develop after infection and can remain detectable for months or years. The fluorescent antibody technique highlights these antibodies if they are present, allowing lab technicians to identify them under a microscope.

Why It’s Done

Your healthcare provider may order this test if you have symptoms like fever, fatigue, joint pain, or a characteristic rash (e.g., bull’s-eye rash) that could suggest Lyme disease. It’s also used to confirm a diagnosis in people with suspected early or late-stage infection.

A blood sample is drawn from a vein in your arm, and the serum or plasma is separated for testing. This sample is then processed and analyzed in a lab using the fluorescent antibody method.

No special preparation is needed, but avoid taking antibiotics for at least two weeks before testing, as they may affect antibody levels.

A positive result indicates the presence of *Borrelia burgdorferi* antibodies, suggesting past or current infection. However, false positives can occur, so results are often interpreted alongside clinical symptoms and other tests. A negative result means no detectable antibodies were found, but this doesn’t rule out Lyme disease entirely.

A positive result may prompt further testing (e.g., Western blot) to confirm the diagnosis. If you’re at risk of Lyme disease (e.g., due to outdoor activities in endemic areas), follow-up testing may be recommended even with negative results.