Immunoassays and Methods to Diagnose Syphilis by Immobilizing a Lipoidal Antigen on a Solid Support

Syphilis, a genital ulcerative disease caused by the bacterium Treponema pallidum, is associated with significant complications if left untreated. Syphilis rates in the United States have been increasing.

CDC scientists have developed a method for capturing anti-lipoidal antibodies that are produced during syphilis infection. This method works by immobilizing a lipoidal antigen including (but not limited to) cardiolipin, lecithin and cholesterol on a solid support such as a nitrocellulose membrane. When the membrane-bound lipoidal antigen is exposed to a patient serum sample, any antibodies specific for the lipoidal antigen will be captured, allowing for easy detection. Detection may be accomplished by a visual, qualitative method producing results that are easy to read and interpret. The test can be used at the point-of-care (POC), in rural areas and/or in field studies. This method is adaptable for use with other antigen-antibody interactions and diagnostics for additional diseases characterized by the presence of anti-lipoidal antibodies.