Pathology Most commonly used treponemal test in diagnosis of syphilis is: A TPI (Treponema pallidum immobilisation) B TPIA (Treponema pallidum immune adherence) C TPHA (Treponema pallidum haemagglutination) D FTA ABS (Fluorescent treponemal antibody absorption test) 💡 Explanation Most commonly used treponemal test in diagnosis of syphilis is: ✓ Correct Answer: C. TPHA (Treponema pallidum haemagglutination)