Application of Neutral Red Staining for Evaluation of the Viability of Dermatophytes in Human Skin Scales

Abstract

To elucidate discrepancies in the results obtained by direct microscopic examination and subsequent culture, the viability of dermatophytes in the scales was evaluated by neutral red staining. When the results of the staining of fungal elements in skin scales taken from 110 tinea patients were compared with those of subsequent culture on Sabouraud's dextrose agar, a strong positive correlation was found between the two sets of results. Autoradiographic study using 3H-thymidine showed that grain-positive cells (living cells) were stained with neutral red, whereas negative cells (dead cells) were not stained. These findings suggest that neutral red staining is a useful method for evaluation of the viability of dermatophytes in human skin scales. © 1992, The Japanese Society for Medical Mycology. All rights reserved.