A female patient with a new genital lesion presents to your sexually transmitted disease clinic. She is homeless, has no health insurance, and is an intravenous drug user. You suspect syphilis. Which of these techniques would be most appropriate to emonstrate treponemes?
A) Immunological test such as the VDRL B) Dark-field microscopy C) Acid-fast stain D) Gram stain E) Electrophoresis