To detect the multinucleated giant cells confirming the presence of a herpes infection.
Microscope, Bunsen burner, glass microscope slide, 5% methylene blue or Wright stain or Giemsa stain, immersion oil, and sterile scalpel or hypodermic needle.
Unroof a fresh, uncrusted vesicle with a sterile hypodermic needle or scalpel.
Scrape the floor of the vesicle with the scalpel and smear scrapings of the lesion onto a glass microscope slide.
Let air dry.
Fix specimen with absolute alcohol or gentle heat.
Stain with blue stain (5% methylene blue, Wright stain, or Giemsa stain) for 5 seconds, rinse, and air dry.
View preparation through immersion oil at high power (×40-50).
Tzanck Preparation. A Tzanck preparation of both the roof and floor of a herpetic vesicle demonstrating a multinucleated giant cell. (Photo contributor: Department of Dermatology, Wilford Hall USAF Medical Center and Brook Army Medical Center, San Antonio, TX.)