To measure the pH, apply a small amount of vaginal secretions to a strip of pH paper and spread with a wooden spatula. The normal pH of vagina is 3.8 to 4.2. Certain factors may alter the pH, such as saline, the lubricant of the speculum, and menstrual secretions. It is cheap and easy to perform. The yield is higher with KOH than with saline preparations.
Bacteria suggestive of lactobacilli are a normal finding.
They appear as long and rod-shaped organisms. White blood cells indicate trichomonas or cervicitis. Other findings as indicated above under lower power. The addition of KOH to a vaginal swab produces a strong fishy odor due tot he release of amines produced by bacterial overgrowth.