Rapid intraoperative examination of tissues for fungi is important for the surgical control of infection. Staining of frozen or paraffin-embedded tissues with calcofluor white (CFW) is a rapid nonspecific method for the identification of fungal infection. When viewed with a fluorescence microscope, fungal elements stained with CFW are sharply delineated from surrounding tissue and easily identified. Calcofluor white also stains tissue elements such as keratin, collagen, and elastin, which provide useful landmarks for the examination. To a much lesser degree, bacteria are also stained with CFW.