The cost of the syphilis spirochete antibody test is about $30, but you cannot check for syphilis spirochete antibodies alone. If syphilis is suspected, a non-syphilis spirochete antibody test, also known as a rapid plasma reactin test, is also required and costs about $30. The titer of non-syphilis spirochete antibodies is used to determine whether the person has been infected with syphilis. A titer above 1:8 is considered to be infected with syphilis; a titer below 1:8 may be a false positive, such as pregnancy, cirrhosis of the liver, and acute infectious diseases, which can lead to false positives. It is recommended that 2-3 months after the occurrence of unclean sexual intercourse, blood tests should be taken to clarify whether syphilis is infected, but if clinical symptoms appear, such as hard chancre, it is necessary to go to a regular hospital for dark field examination of secretions in a timely manner.