To make a correct diagnosis of a blistering disease, he must extract some of the fluid from the blister and do a Gram stain, and you must scrape the base of the blister to obtain epidermal cells (shown here with the person using #15 scalpel blade) and smear this on a slide. The fluid for Gram stain should be affixed so that it adheres to the slide during the staining process. The scraping for Wright stain that was smeared on the slide should not be heat fixed as this tends to destroy the cell morphology and make it very difficult, if not impossible, to make a diagnosis.
