Electron microscopic examination of ribosome preparations from germinated spores of Aspergillus fumigatus.

Ribosomes were isolated from germinated spores (germlings) of Aspergillus fumigatus and electron microscopy was used to determine qualitatively the extent of cellular contamination. After differential centrifugation, the initial crude preparation contained 80S ribosomes and numerous membrane contaminants in the form of membrane sheets, palisade aggregates, and vesicles 0.10-0.18 micron in size. Gel filtration chromatography of crude ribosomes in Sepharose CL-4B did not remove all of the membrane contamination. Homogenous ribosome suspensions, morphologically free of other cellular component contamination, were then obtained after gel filtration fractions were centrifuged through a 35% sucrose solution. The total ribosome yield from a germling preparation was approximately four times the yield of ribosomes from a comparable spore preparation. Gel diffusion precipitin patterns of germling ribosomes were identical to those of spore ribosomes with both germling and spore ribosomes antisera.