Several types of laboratory tests for Lyme disease are available. These tests identify antibodies to the bacteria that cause Lyme disease, so they are most reliable a few weeks after infection has occurred when the body has time to develop antibodies. But even then, the tests aren't foolproof.
The CDC recommends a two-step process when testing blood for evidence of Lyme disease. Both steps can be done using the same blood sample and include:
Testing antibodies to Borrelia burgdorferi by immunofluorescence (IFA) or ELISA. These tests are extremely sensitive and may yield false positives.
A Western blot test should be performed to confirm the findings of the initial test. This test is much more specific and will rule out any false positives.
Other types of laboratory testing, which have not been adequately established also exist, such as urine antigen tests, immunofluorescent staining for cell wall-deficient forms of Borrelia burgdorferi, and lymphocyte transformation tests. The CDC does not recommend these tests, and encourages patients to ask their health care provider if the tests performed on them for Lyme disease were done using appropriate guidelines and validated methods.