Comparación de algunos métodos de procesamiento para Fonsecaea pedrosoi al microscopio electrónico de rastreo

Abstract

Some conventional procedural methods were evaluated for the ultrastructural study of fungi by scanning electron microscope (SEM). Microcultures of Colombian strains of Fonsecaea pedrosoi isolated from patients injuries from the Federico Lleras Acosta Dermatological Institute, Santafé de Bogotá, Colombia, were used. The results showed alterations, distortions or artifacts on the processed fungi by three of the methods used, probably dueto physical or chemical effects during the processing. Fixation with pure acrolein vapors and Os0,crystals with dehydration and high vacuum drying, avoided the loss of come structures and characteristic arrangements, was also fast, provided easy manipulation of the specimen and needed less reagents. The importance of the SEM is emphasized by the morphological, structural and taxonomical study of the fungi: the use of acrolein vapors for fixation and high vacuum drying as methodological alternatives for the processing of biological samples which are difficultto manipulate or that present easy alteration due to their high hydrophillic composition.