Dark ground microscopy is used for: (A) TPI, (B) Kahn's test, (C) FTA-ABS, (D) VDRL
Answer is A. Treponema pallidum immobilization (TPI) test Serum of patient with complement and T. pallidum are maintained in a complex medium anaerobically If the antibodies are present, the Treponemes are immobilized when examined under dark ground illumination.