The fine structure of the intracytoplasmic organelles of mycobacteria was studied by means of electron microscopy of ultrathin sections. A well-preserved nuclear apparatus was obtained by fixation with OsO(4) in acetate-veronal buffer, containing calcium and tryptone, or in collidine-HCl buffer, followed by uranyl-acetate treatment and embedding in araldite. A low density nuclear region was fil...

Citric acid is found along with uranyl in the subsurface of former nuclear facilities because of its use as a decontamination agent in the nuclear industry. Citrate’s metal chelating properties affect the mobility of uranyl in the subsurface and consequently, citrate biodegradation may significantly impact uranyl fate and transport. Under the non-growth conditions considered, low (micromolar) u...

A procedure for the in vitro growth of well-ordered two-dimensional sheets from ribosomal particles using salts and salt-alcohol mixtures has been developed. Employing this procedure, ordered two-dimensional sheets of the wild type as well as of mutated 50 S ribosomal subunits from Bacillus stearothermophilus can readily be obtained. These sheets, stained with uranyl acetate or gold-thioglucose...

The staining affinity of electron dense stains to mouse palatal elastic fibers and periodontal oxytalan fibers was assessed and compared. Tissues were stained routinely with uranyl acetate and lead citrate or with elastic tissue stains including: (1) silver tetraphenylporphine sulfonate, (2) tannic acid technique, and (3) a high iron diamine sequence. Staining results were assessed with an elec...

Resolution for 125I-labeled specimens under electron microscope (EM) autoradiographic conditions was assessed experimentally. With this isotope the size of the silver halide crystal was the most important resolution-limiting factor. Heavy metal staining such as is routinely used in preparing animal tissues for EM autoradiography produced an improvement in resolution of approximately 15-20%. For...

on a conventional ultramicrotome. Semi-thin sections on grids were stained with the Giemsa method and methylene blue-azure II-basic fuchsin. Staining without removal of the embedding matrix was sharp and brilliant. These stained sections were observed under a light microscope. For electron microscopy, they were doubly stained with uranyl acetate and lead salt. Identical sites on such sections c...