The Syphilis Ab Rapid Test Cassette uses a combination of syphilis antigen-colloidal gold conjugate and immobilized syphilis antigen to detect T. pallidum antibodies (IgG, IgM and IgA) qualitatively and selectively in whole blood, serum or plasma.

Treponema pallidum is a spirochete bacterium and the causative agent of the venereal disease syphilis.  Its natural course presents in three stages: primary, secondary and tertiary or late syphilis with long periods of latency or inactive disease. Primary syphilis infection is defined by the presence of a chancre at the site of inoculation. The antibody response to the T. pallidum bacterium can be detected within 4 to 7 days after the chancre appears and remains detectable until the patient receives adequate treatment.