A preliminary and rapid microscopic examination is performed on a vaginal swab sample taken from inside the vagina. The swab contents are deposited onto two microscope slides: one with a drop of normal saline and the other with a drop of 10% potassium hydroxide (KOH). The slides are then examined under the microscope to detect: key cells (cloue cells) of bacterial vaginosis (BV), fungal cells or hyphae of candidiasis, and Trichomonas parasites.