[Use of freeze-fracturing to observe the ultrastructure of Candida albicans with scanning electron microscopy].
The development of the techniques of sample preparation for the observation of ultrastructure with scanning electron microscopy (SEM) include, among others, the method O-D-O reported by Tanaka and Naguro in 1981, based on the initial fixing of the specimen (eukaryotic tissue) in 1% OsO4; treatment with dimethyl sulphoxide (DMSO) as a cryoprotectant, followed by cryofracture, removal of cytoplasmatic matrix by psot-fixing with 1% OsO4 and a further conductive stain. In this paper we report the application of the method O-D-O in a culture of Candida albicans modifying the pre-fixing carried out overnight and excepting the osmic maceration, in order to observe the cell ultrastructure of this eukaryotic microorganism with SEM at a normal resolution. Through the tridimensional images obtained, in which we can observe the fracture of Candida albicans without cytoplasmatic matrix but with details of a normal and deformed cell wall, as well as cells conserving their cytoplasmatic matrix where globose and filamentous structures become evident and suggest a pattern of organization and cells with a very clear character of what we believe is the nuclear zone of the microorganism, we night conclude that our method is suitable for eukaryotic unicellular organisms in order to observe the cell ultrastructure with SEM at normal resolution and show images comparable with those reported with SEM at high resolution, contributing to the development of the ultrastructural cytology, traditionally restricted to the transmission electron microscopy (TEM). These findings reveal an additional aid which will allow to obtain a clearer aspect of the complex cell structure of unicellular organisms.
Portillo
S A
SA
Universidad de Carabobo, Facultad de Ciencias de la Salud, Laboratorio de Microscopia Electrónica, Ciadana, Maracay, Estado Aragua, Venezuela.
Castejón
O C
OC
Araujo
B
B
D002176:Candida albicans / Q000648:ultrastructure*; D005614:Freeze Fracturing; D008855:Microscopy, Electron, Scanning
Uso de criofractura para observación de la ultraestructura en Candida albicans con microscopía electrónica de barrido.