Consider the following serological tests:
1. Treponema Pallidum Immobilization Test (TPI)
2. T. Pallidum Haemagglutination Assay (TPHA)
3. Fluorescent Treponemal Antibody Absorbed Test (FTA-ABS)
4. Venereal Disease Research Laboratory Test (VDRL)
Which of these are specific for diagnosing syphilis?