Determine the presence or absence of fungal forms in clinical specimens submitted for direct microscopic exam
KOH/calcofluor: Microscopic examination of nails does not have the sensitivity of culture. KOH alone can be difficult to read and time-consuming. KOH plus the whitener calcofluor increases the sensitivity of the smear. The KOH/calcofluor requires a fluorescence microscope for reading but is superior to KOH alone and replaces the PAS stain for detection capabilities. Positive smears using KOH/calcofluor can be expected in about 60% of positive cultures. If the smear is positive then the likelihood that the culture will grow a dermatophyte is greater than if the smear is negative.
Biopsy, body fluid, aspirates, bronchoalveolar lavage (BAL), skin, nails, hair, sinus, sputum, stool, swab of conjunctiva, throat, tissue, urine, or vaginal
50 mL BAL, 5 mL fluid, 2 mL tissue
Sterile leakproof container or swab
Usual sterile preparation.
Biopsy: Surgical specimen in sterile container. A small amount of sterile nonbacteriostatic water should be used to prevent drying.
Body fluid, aspirates: Aspirated material in sterile container.
Skin and nails: Cleanse the area with 70% alcohol prior to specimen collection. Nail scraping should be from a subsurface portion of the infected nail. Skin should be taken from the active border of the lesion.
Hair: Epilate 10 to 12 hairs and place them in a sterile container.
Stool: Random sample in sterile container.
Swabs of throat, nose, nasopharynx, ear, vagina: Swab affected area or visible lesion.
Urine: Clean catch midstream sample in sterile container.
Wound: Purulent material, fluid, scraping of lesion border, or swab (least preferred) in sterile transport container. Swabs cannot be split for other tests.
Avoid contamination of the specimen with commensal organism as much as possible. Specify the source of the specimen and include any pertinent clinical information.
Maintain specimen at room temperature.
Swab without evidence of specimen present; leaking specimen; inappropriate specimen transport device including syringe with needle; unlabeled specimen or name discrepancy between specimen and request label; specimen received after prolonged delay (usually more than 72 hours); specimen received in expired transport; fungal stain (KOH/Calcofluor) cannot be performed on blood