The Lyme ImmunoBlot is a qualitative assay that detects antibodies to B. burgdorferi strains and species. This test includes IgG and IgM antibodies. IgM antibodies may be present as early as 1 week after a tick bite and will usually remain present for six to eight weeks after initial exposure. IgG antibodies are typically present a few months following initial infection. This test is unavailable for patients over 65 when ordered through physician services.