TP-ab refers to syphilis-specific antibodies, measured quantitatively with a normal value of ≦1. 1. Syphilis-specific antibodies are serum markers of syphilis spirochete infection. Syphilis spirochetes can penetrate intact mucous membranes or tiny abrasions in the skin, and are generally transmitted through direct sexual contact. After infection, the immune system makes reactive antibodies against the syphilis spirochete. 2. Qualitative methods of detection, generally out of the window period test results seronegative can be ruled out syphilis infection, seropositive represents syphilis previous infection or current infection. 3. Through quantitative methods such as chemiluminescence to detect syphilis spirochete antibodies, the normal reference range is 0 to 1, less than or equal to 1 is normal, if greater than 1 means abnormal, suggesting that may be infected with syphilis.