To the Editor.
—Krieger et al1 have done a beautiful study on the diagnosis of Trichomonas vaginalis infection. The only criticism I have concerns the preparation of the wet mount. A Popsicle stick (or Papanicolaou smear scraper), not a cotton-tip swab, should be dipped in the vaginal puddle and immediately transferred to a drop of saline already placed on a clean glass slide. This preparation should then promptly (preferably less than a minute and certainly no more than two minutes) be examined under the ordinary light microscope at low power. Trichomonads will lose motility rapidly with delay or under the hot light of the microscope. A coverslip should not be applied until after initial perusal under low power. The "two fast legs" system is necessary to have a high percentage of positive wet preparations.2