Transmission and scanning electron microscopy of whole glioma cells cultured in vitro

Twenty-six lines of malignant glioma cells have been established in our laboratories. The cell lines have all been derived from low-differentiated human astrocytomas which did not differ in their histopathological classification. A representative selection of these lines was cultured on formvar-covered, carbon stabilized, gold, EM grids. After glutaraldehyde and osmium fixation, they were dehydrated, critical-point dried and studied as whole-cell preparations in the transmission electron microscopy (TEM) mode. The specimens were then coated with 10-nm of a gold/palladium alloy and the same cells identified and examined in the scanning electron microscopy (SEM) mode. This combined TEM and SEM method makes it possible to relate intracellular structures to surface details, such as ruffles, endocytotic vacuoles, filopodia and microvilli. The study also revealed a large spectrum of dissimilarities between the studied lines, which underlines the fact that no essential structural features of a tumor type can be drawn from studies on occasional lines of cells derived from it.