Hochaufl�sende Gefrier�tzung

Bachmann, L.; Abermann, R.; Hp, Zingsheim

doi:10.1007/bf00268707

Cited by 33 publications

(9 citation statements)

References 13 publications

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“…4,6,7,8) gives a finer grain than platinumkarbon (Pt/C) replication (Figs. 3, 5, 9, lo), as reported by Bachmann et al (1969Bachmann et al ( , 1985 and Gross et al (1985). Ta/W replicas are on average 0.2 nm thick (i.e., 10-20% of the thickness of PtlC replicas as measured by a quartz crystal monitor).…”

Section: Replication Methodsmentioning

confidence: 98%

Freeze‐Fracture, Deep‐Etch, and Freeze‐Substitution Studies of Olfactory Epithelia, With Special Emphasis on Immunocytochemical Variables

Menco

1995

Microscopy Res & Technique

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Freeze-fracturing and deep-etching are a well-suited set of methods to study membrane and cytoplasmic features. Various approaches are available. Possible variables include tissue preparation, fracturing only or fracturing followed by etching, modes and materials of replication, and various ways of combining freeze-fracturing and/or deep-etching with (immuno)cytochemistry. Freeze-substitution, in particular combined with embedding in methacrylate resins such as the Lowicryls, is becoming rather widely accepted for purposes of ultrastructural (immuno)cytochemistry. Most investigators active in this field agree that this combination yields superior results compared to (immuno)cytochemistry combined with more conventional means of thin section transmission electron microscopy. Yet relatively little information is available on the variations that can occur with different approaches of freeze-substitution immunocytochemistry. This review deals with some of the variations in freeze-fracturing, freeze-etching, and freeze-substitution as applied to olfactory epithelial structures and with the effectiveness of observations obtained by application of the above sets of methods in relating the special morphology of olfactory epithelial cellular structures with those obtained by other approaches. Indeed, the data obtained continue to provide an integral image in which that morphology can be related to the special biochemistry, cell and molecular biology, and electrophysiology of olfactory epithelial structures.

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Section: Replication Methodsmentioning

confidence: 98%

Freeze‐Fracture, Deep‐Etch, and Freeze‐Substitution Studies of Olfactory Epithelia, With Special Emphasis on Immunocytochemical Variables

Menco

1995

Microscopy Res & Technique

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“…Ta/W has the advantage in that it provides a finer grain, and the replicas can thus be thinner than Pt/C replicas. Hence, especially at a high magnification, Ta/W replicas describe better the outlines of the structures of interest (Bachmann et al, 1969;Gross et al, 1985;Plattner and Zingsheim, 1983;Southworth et al, 1975;Zingsheim and Plattner, 1976;Zingsheim et al, 1970). Under very high vacuum conditions (pressure < 10pgmbar) at very low temperatures (-260°C) Pt/C shadowing also gives a fine grain replica (Gross et al, 1985).…”

Section: Freeze-fracture Freeze-etch and Freeze-substitution Technomentioning

confidence: 95%

“…Walley, Cressington Scientific, Watford, U.K., personal communication). The heat load on the samples is approximately equivalent for both replication mixtures, and Ta/W is actually somewhat better in that respect (Bachmann et al, 1969). Replication can be carried out unilaterally at angles of, most commonly, around 45", or by rotary replication (Chandler, 1986), for which angles of around 20" to 25" are suggested to be optimal.…”

Section: Freeze-fracture Freeze-etch and Freeze-substitution Technomentioning

confidence: 99%

A survey of ultra‐rapid cryofixation methods with particular emphasis on applications to freeze‐fracturing, freeze‐etching, and freeze‐substitution

Menco

1986

J. Elec. Microsc. Tech.

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“…High-resolution shadowing with tantalum-tungsten was performed with an electron-beam evaporator designed to minimize damage to biological specimens (5,6,13). The high evaporation rates obtainable with this evaporator allowed a short evaporation time of 10 sec, and a large source-to-specimen distance of 18 cm.…”

Section: Methodsmentioning

confidence: 99%

“…Modification of an electron-bombardment gun has eliminated the obstacle to the biological application of this technique, and such high-resolution shadowing has been successfully applied in freeze-etching (5). In this study, we used an electron-bombardment evaporator to shadow monomeric and dimeric samples of tRNA with tantalumtungsten.…”

mentioning

confidence: 99%

High-Resolution Shadowing of Transfer RNA

Abermann

Yoshikami

1972

Proc. Natl. Acad. Sci. U.S.A.

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High-resolution shadowing with metals that melt at high temperatures was used to study macromolecules. Molecules of transfer RNA shadowed with tantalum-tungsten are readily visualized in an electron microscope. Mounting procedures for tRNA were perfected that reproducibly gave uniform distributions of both monomeric and dimeric tRNA particles, and allowed a statistical assessment of their gross shapes and sizes. Monomeric tRNA yielded a fairly homogeneous population of rod-shaped particles, with axial dimensions of about 40 X 85 A. Dimers of yeast alanine tRNA held together by hydrogen bonds and dimers constructed by covalent linkage of the amino-acid acceptor (3'-) termini of monomers both gave slightly more heterogeneous populations of particles. Yet, their structures were also basically rod shaped, with their lengths ranging to about twice that of the monomer; this result indicates an endto-end arrangement of the monomeric units within both dimers. These results suggest that the amino-acid acceptor terminus and the antLcodon region are at the ends of the rod-shaped, dehydrated tRNA monomer visible by electron microscopy, consistent with the generally accepted view of tRNA structure in solution suggested by other workers using other methods. This study demonstrates that highresolution shadowing with tantalum-tungsten provides a means to examine the three-dimensional structures of relatively small biological macromolecules.

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Hochaufl�sende Gefrier�tzung

Cited by 33 publications

References 13 publications

Freeze‐Fracture, Deep‐Etch, and Freeze‐Substitution Studies of Olfactory Epithelia, With Special Emphasis on Immunocytochemical Variables

Freeze‐Fracture, Deep‐Etch, and Freeze‐Substitution Studies of Olfactory Epithelia, With Special Emphasis on Immunocytochemical Variables

A survey of ultra‐rapid cryofixation methods with particular emphasis on applications to freeze‐fracturing, freeze‐etching, and freeze‐substitution

High-Resolution Shadowing of Transfer RNA

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